From nobody Wed Dec 20 23:07:01 2023 X-Original-To: freebsd-arm@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4SwTjJ6CSHz55S33 for ; Wed, 20 Dec 2023 23:07:16 +0000 (UTC) (envelope-from marietto2008@gmail.com) Received: from mail-ej1-x62c.google.com (mail-ej1-x62c.google.com [IPv6:2a00:1450:4864:20::62c]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1D4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4SwTjJ2gYrz3bdK for ; Wed, 20 Dec 2023 23:07:16 +0000 (UTC) (envelope-from marietto2008@gmail.com) Authentication-Results: mx1.freebsd.org; none Received: by mail-ej1-x62c.google.com with SMTP id a640c23a62f3a-a22f59c6ae6so19071666b.1 for ; Wed, 20 Dec 2023 15:07:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1703113634; x=1703718434; darn=freebsd.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=5tvXPRe/mAQjg0sddjHVIyS7OLk6FPp+bxTAGQzZ2XI=; b=Hn00AfiP9yyOBYe+fthKsOSCuuITsMUm/HM9qziswGp41dYe/Mm/s8A++ooUTtLjKX Lhs9dSITk5uXxVodC2cBB+wsd6ES/vAeFQcHtUb3IeJvEiA21h+0SLNoCRH+FtKyIyZT c2KdBT62DWkECzLKR3oWRS0QqHtS6YVrLN7Nwk2PiRBOy6oV7nrSmMJfvF7Qds4ncNJJ 9ss54N5Ys2L0X/749n+sl+dqK/lXA/+iyQjYalwDFz1D564TnawcIBLz8TNjQTeylzvA zu4uPABj2+kw5QQ0n7bXoLk+k2ovf6dVvFacv1r5f3pqPBMu7HI6hXHA0HOe65MQ0hTd NKHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1703113634; x=1703718434; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=5tvXPRe/mAQjg0sddjHVIyS7OLk6FPp+bxTAGQzZ2XI=; b=vaCQSXnqSZmRBT4u1++HPn7q7LiWqscQSwx/od7vtZpmMaQIgU54cJzX3sM+uLWWod 2bESfKwarvsjt9KqpiEWBejz7n1xTKVIlbdAG1uj7On0mKWcOPnPql/ZUJpuuxctKXhx xpRhaxGiUXm3FQsKRfTzYm2s1s24b9evBiB1+XXXYAD/AHorscXbEebiz1Jxeb6vC4DO UM6+26DVTbQfz6BjnzWRO1EqGEwSGs4nEFbWjilsmIEziGTIk4bS/DWOR/PZTU6b8a4C ydKtYWeUYf5mLd/vTy4dzDX5H2BwfJs7o+OvhGGRF/pArPG+Oa6o4i3toj2seads0NBf x7Vg== X-Gm-Message-State: AOJu0YyVfieojbCF0OkuOAQnW8ohnBZSmhDY6cYHBrybvwMqma+nHOS3 LTJyV4fgi3IDXOjvQ4fXsQBZ5G+x0Fc1gTmkXJk= X-Google-Smtp-Source: AGHT+IEfs6aJRtOA9pYaP2n4IkEAZ05Il064hHM4MIu1DqmwA2xfvqr6aym2jGZNgvCtg/w6gOb18nQgDpIG4Mg6Q1U= X-Received: by 2002:a17:906:2b16:b0:a23:6a65:9fc3 with SMTP id a22-20020a1709062b1600b00a236a659fc3mr1174610ejg.63.1703113634075; Wed, 20 Dec 2023 15:07:14 -0800 (PST) List-Id: Porting FreeBSD to ARM processors List-Archive: https://lists.freebsd.org/archives/freebsd-arm List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-arm@freebsd.org MIME-Version: 1.0 References: <97aa980b9b44.6eb7f9d5c54e7@mailgate.us> <54C44649-91A1-4A41-B2BA-FFCCACD0099D@edc.ro> In-Reply-To: From: Mario Marietto Date: Thu, 21 Dec 2023 00:07:01 +0100 Message-ID: Subject: Re: How to boot FreeBSD for arm 32 bit as DomU with u-boot on my ARM Chromebook To: Warner Losh Cc: titus , freebsd-arm Content-Type: multipart/alternative; boundary="0000000000002bd665060cf90b00" X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:15169, ipnet:2a00:1450::/32, country:US] X-Spamd-Bar: ---- X-Rspamd-Queue-Id: 4SwTjJ2gYrz3bdK --0000000000002bd665060cf90b00 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Warner,you didnt read one of my last email,where i said that i have fixed that bug and I can boot my freebsd image with qemu and even the network interface works well. I remember to you that my project is to boot freebsd under xen. Thanks. Il mer 20 dic 2023, 23:49 Warner Losh ha scritto: > > > On Wed, Dec 20, 2023 at 12:25=E2=80=AFAM titus wrote: > >> for the panic @ dhcp see >> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D271288 >> https://forums.freebsd.org/threads/kernel-panic-on-armv7-with-qemu.89016= / >> >> its a problem with virtio net driver (was fixed by forum user _martin bu= t >> never went in the main tree) >> if you emulate another nic type will work >> > > Indeed it does. > > https://reviews.freebsd.org/D43136 > > should fix the problem. I think it's the right thing to do. It's what a > lot of other drivers do. > > Warner > > >> On Dec 20, 2023, at 6:52 AM, Warner Losh wrote: >> >> I'd think you'd need the right virtualization loader. I'm not entirely >> sure the u-boot.bin you've been creating is for a dom-u.. >> If I misunderstood, then the below isn't good advice. Chain booting the >> u-boot, the first u-boot initializes things so you want >> to start with stage after the SPL But the different error messages >> suggest that it's trying to reboot with kexec, which >> isn't supported on armv7 at the moment. >> >> If you could boot in kvm, I think that the following would work.... >> Though I'm not entirely sure how to >> specify the two .fd files in your setup. The use of qemu is to have an >> easy env to debug things... I don't >> have a chromebook to try... >> >> My first instinct would be to try qemu on x86 (this is the first step of >> many to get to your destination). >> >> If you could boot the GENERIC_SD image that we produce using qemu + >> edk2-arm-code.fd that would >> be a huge first step. This will give you the boot loader, I believe, to >> boot in the VM that you need better >> than going via the u-boot route. Since you are booting in a virtualized >> environment, I think it wouldn't >> matter which one :). >> >> So, I did the following to boot the virtualized armv7 FreeBSD >> environment, following a post on the forums I found and knew to have the >> right recipe: >> >> https://forums.freebsd.org/threads/run-boot-freebsd-arm-32bit-image-in-q= emu.80765/ >> >> 1. pkg install qemu >> 2. mkdir qemu-armv7-env >> 3. cd qemu-armv7-env >> 4. fetch >> https://download.freebsd.org/releases/arm/armv7/ISO-IMAGES/14.0/FreeBSD-= 14.0-RELEASE-arm-armv7-GENERICSD.img.xz >> 5. xz -d -T 0 FreeBSD-14.0-RELEASE-arm-armv7-GENERICSD.img.xz >> 6. dd if=3D/dev/zero of=3Dpflash0.img bs=3D1m count=3D64 >> 7. dd if=3D/dev/zero of=3Dpflash1.img bs=3D1m count=3D64 >> 8. dd if=3D/usr/local/share/qemu/edk2-arm-code.fd of=3Dpflash0.img >> conv=3Dnotrunc >> 9. dd if=3D/usr/local/share/qemu/edk2-arm-vars.fd of=3Dpflash1.img >> conv=3Dnotrunc >> 10. cat > start-freebsd-arm.sh >> #!/bin/sh >> qemu-system-arm \ >> -M virt \ >> -m 1024 \ >> -drive file=3Dpflash0.img,format=3Draw,if=3Dpflash,readonly=3Don \ >> -drive file=3Dpflash1.img,format=3Draw,if=3Dpflash \ >> -drive file=3D$1.img,if=3Dvirtio,cache=3Dwritethrough \ >> -nographic \ >> -serial mon:stdio >> ^D >> 11. chmod +x start-freebsd-arm.sh >> 12. ./start-freebsd-arm.sh FreeBSD-14.0-RELEASE-arm-armv7-GENERICSD >> >> But I hit a snag with this on qemu 8.1.2 and 8.1.3 with both 13.2 and >> 14.0: >> >> Starting devd. >> Starting dhclient. >> DHCPDISCOVER on vtnet0 to 255.255.255255 port 67 interval 7 >> Fatal kernel mode data abort: 'Alignment Fault' on read >> trapframe: 0xc4b36a60 >> FSR=3D00000001, FAR=3Ddd96701a, spsr=3D20000013 >> r0 =3D00000000, r1 =3D00000001, r2 =3D00000001, r3 =3Dc4b36b4c >> r4 =3D00000014, r5 =3Dd6618800, r6 =3Ddd96702e, r7 =3D0000022c >> r8 =3D00000000, r9 =3D0000022c, r10=3Ddd96701a, r11=3Dc4b36b90 >> r12=3D4300ffff, ssp=3Dc4b36af0, slr=3Dc04a9728, pc =3Dc04a9750 >> >> panic: Fatal abort >> cpuid =3D 0 >> time =3D 1680843057 >> KDB: stack backtrace: >> #0 0xc035786c at kdb_backtrace+0x48 >> #1 0xc02fdd20 at vpanic+0x140 >> #2 0xc02fdbe0 at vpanic+0 >> #3 0xc06304ac at abort_align+0 >> #4 0xc063052c at abort_align+0x80 >> #5 0xc063017c at abort_handler+0x480 >> #6 0xc060f480 at exception_exit+0 >> #7 0xc04a9750 at udp_input+0x288 >> #8 0xc0473f54 at ip_input+0x1e0 >> #9 0xc04447c0 at netisr_dispatch_src+0xf8 >> #10 0xc043bf2c at ether_demux+0x1a4 >> #11 0xc043d5e4 at ether_nh_input+0x480 >> #12 0xc04447c0 at netisr_dispatch_src+0xf8 >> #13 0xc043c404 at ether_input+0x50 >> #14 0xc01c0838 at vtnet_rx_vq_process+0x880 >> #15 0xc01b70d0 at vtpci_intx_intr+0xac >> #16 0xc02b87f0 at ithread_loop+0x2ec >> #17 0xc02b465c at fork_exit+0xc0 >> Uptime: 19s >> >> I don't know if this is a problem with qemu or FreeBSD's kernel... >> >> Warner >> >> On Tue, Dec 19, 2023 at 3:25=E2=80=AFPM Mario Marietto >> wrote: >> >>> I've asked some help on the channel #arm on Reddit and someone replied = : >>> >>> >>> https://www.reddit.com/r/arm/comments/18mcir8/i_cant_boot_freebsd_for_a= rm32_bit_as_domu_with/ >>> >>> Maybe his answer can be useful to understand why it does not work. >>> >>> On Tue, Dec 19, 2023 at 8:33=E2=80=AFPM Stefano Stabellini < >>> sstabellini@kernel.org> wrote: >>> >>>> +Michal >>>> >>>> Hi Mario, >>>> >>>> I am not sure about booting FreeBSD, but I am certain that u-boot work= s >>>> fine as DomU kernel on ARMv8 (not sure about ARMv7). With this config >>>> file: >>>> >>>> name=3D"test" >>>> kernel=3D"u-boot.bin" >>>> extra =3D "console=3Dhvc0" >>>> memory=3D256 >>>> vcpus=3D1 >>>> disk =3D [ 'FreeBSD-13.2-RELEASE-armv7.img,raw,xvda' ] >>>> >>>> I don't know for sure if you can boot FreeBSD but you should definitel= y >>>> be able to see the u-boot command line prompt. The fact that you are >>>> getting this message: >>>> >>>> xc: error: panic: xg_dom_core.c:689: xc_dom_find_loader: no loader >>>> found: Invalid kernel >>>> >>>> Means that something is not right in the u-boot configuration or u-boo= t >>>> build. Michal and Artem (CCed) might know more. From what I recall, >>>> there was nothing special required to get u-boot.bin to boot as domU >>>> kernel, so now I wonder if it is an ARMv7 vs. ARMv8 issue. >>>> >>>> Cheers, >>>> >>>> Stefano >>>> >>>> >>>> On Tue, 19 Dec 2023, Mario Marietto wrote: >>>> > ....I see that some other interesting files have been produced by >>>> u-boot when I have compiled it : >>>> > >>>> > u-boot >>>> > u-boot.lds >>>> > u-boot.bin >>>> > u-boot.map >>>> > u-boot-nodtb.bin >>>> > u-boot.dtb >>>> > u-boot.srec >>>> > u-boot-dtb.bin >>>> > u-boot.sym >>>> > >>>> > So,maybe I should use a different u-boot* file for booting FreeBSD ? >>>> > >>>> > >>>> > On Tue, Dec 19, 2023 at 4:28=E2=80=AFPM Mario Marietto < >>>> marietto2008@gmail.com> wrote: >>>> > Hello to everyone. >>>> > >>>> > I have compiled the needed u-boot.bin from scratch using this >>>> procedure : >>>> > >>>> > # git clone https://github.com/u-boot/u-boot.git >>>> > # cd u-boot >>>> > # ARCH=3Darm CROSS_COMPILE=3Darm-linux-gnueabihf- make snow_defconfi= g : >>>> this line generates the file .config >>>> > # nano .config and I've added these parameters : >>>> > >>>> > CONFIG_ARMV7_NONSEC=3Dn >>>> > CONFIG_EFI_GRUB_ARM32_WORKAROUND=3Dy >>>> > >>>> > the uboot-bin file is generated with this command : >>>> > >>>> > # ARCH=3Darm CROSS_COMPILE=3Darm-linux-gnueabihf- make >>>> > >>>> > At this point,I took a look inside the .config file and I saw that >>>> the parameter "CONFIG_ARMV7_NONSEC=3Dn" has been removed. So,for >>>> > some reason,it is not accepted and this could be a problem.... >>>> > >>>> > These are the xen config files that I've used : >>>> > >>>> > nano freebsd.cfg >>>> > >>>> > name=3D"test" >>>> > kernel=3D"u-boot.bin" >>>> > extra =3D "console=3Dhvc0" >>>> > memory=3D256 >>>> > vcpus=3D1 >>>> > disk =3D [ 'FreeBSD-13.2-RELEASE-armv7.img,raw,xvda' ] >>>> > >>>> > nano start-freebsd >>>> > >>>> > xl create freebsd.cfg >>>> > xl console freebsd >>>> > >>>> > This is what happens when I launch the vm : >>>> > >>>> > # ./start-freebsd >>>> > >>>> > Parsing config from freebsd.cfg >>>> > xc: error: panic: xg_dom_core.c:689: xc_dom_find_loader: no loader >>>> found: Invalid kernel >>>> > libxl: error: libxl_dom.c:571:libxl__build_dom: xc_dom_parse_image >>>> failed >>>> > libxl: error: libxl_create.c:1640:domcreate_rebuild_done: Domain >>>> 1:cannot (re-)build domain: -3 >>>> > libxl: error: libxl_domain.c:1183:libxl__destroy_domid: Domain >>>> 1:Non-existent domain >>>> > libxl: error: libxl_domain.c:1137:domain_destroy_callback: Domain >>>> 1:Unable to destroy guest >>>> > libxl: error: libxl_domain.c:1064:domain_destroy_cb: Domain >>>> 1:Destruction of domain failed >>>> > freebsd is an invalid domain identifier (rc=3D-6) >>>> > >>>> > >>>> > On Mon, Dec 18, 2023 at 12:39=E2=80=AFPM Mario Marietto < >>>> marietto2008@gmail.com> wrote: >>>> > So,ok,I should have said "the second u-boot" ; since the first >>>> u-boot binary is the "u-boot binary located in the RO >>>> > memory" of the Chromebook". Sorry for the confusion. >>>> > >>>> > On Mon, Dec 18, 2023 at 12:35=E2=80=AFPM Mario Marietto < >>>> marietto2008@gmail.com> wrote: >>>> > ---> There are no specific options in u-boot devoted to FreeBS= D >>>> > >>>> > This is an important factor. So,what about if,instead of compiling a >>>> new version of u-boot on the partition 2,I will >>>> > recompile the u-boot customized version created by the virtual open >>>> system in 2014,that should be installed on the first >>>> > partition ? It could work if there are no differences between the >>>> u-boot that should boot Linux and the u-boot that >>>> > should boot FreeBSD. >>>> > >>>> > Can you give a look at the u-boot source code created by virtual ope= n >>>> systems ? You can find it on my google drive : >>>> > >>>> > >>>> https://drive.google.com/file/d/1eAaZMfd6CU0xiqQfH7sq5wGVzzO09BRm/view= ?usp=3Dsharing >>>> > >>>> > I need to understand if I can recompile it without problem so that i= t >>>> can satisfy my needs (the ability of the file >>>> > u-boot.bin to boot FreeBSD as domU under Xen,as explained by Stefano >>>> Stabellini,the xen developer that suggested to me >>>> > what I could do to have FreeBSD virtualized under Xen on my Arm >>>> Chromebook) ; otherwise the risk is to find later >>>> > problems that will make me troubles and that I will not able to fix. >>>> > >>>> > I gave a look at the virtual open system u-boot and I didn't see any >>>> arndale_defconfig inside. So,If I have understood >>>> > correctly,I should put that file inside the root of the u-boot sourc= e >>>> code,let's say here : >>>> > >>>> > marietto:/home/marietto/Desktop/Files/u-boot_FreeBSD/u-boot-vos # ls >>>> > >>>> > .checkpatch.conf README doc >>>> net >>>> > .git api drivers >>>> onenand_ipl >>>> > .gitignore arch dts >>>> post >>>> > COPYING board examples >>>> rules.mk >>>> > CREDITS boards.cfg fs >>>> scripts >>>> > MAINTAINERS common include >>>> snapshot.commit >>>> > MAKEALL config.mk lib >>>> spl >>>> > Makefile cros mkconfig >>>> test >>>> > PRESUBMIT.cfg disk nand_spl >>>> tools >>>> > >>>> > and I should do : make and make install ? and the file I >>>> need,u-boot.bin will be generated ? >>>> > >>>> > I didn't find any pre made configuration file inside : >>>> > >>>> > u-boot-vos # find . -type f -name "exynos*" >>>> > >>>> > ./include/exynos-fb.h >>>> > ./include/configs/exynos5-common.h >>>> > ./doc/device-tree-bindings/spi/exynos-spi.txt >>>> > ./doc/device-tree-bindings/usb/exynos-usb.txt >>>> > ./drivers/power/exynos-tmu.c >>>> > ./drivers/power/exynos-cpufreq.c >>>> > ./drivers/video/exynos-fb.c >>>> > ./drivers/spi/exynos_spi.c >>>> > ./board/samsung/dts/exynos5250-spring.dts >>>> > ./board/samsung/dts/exynos5250-smdk5250.dts >>>> > ./board/samsung/dts/exynos5250-snow.dts >>>> > ./board/samsung/dts/exynos5250-daisy.dts >>>> > ./arch/arm/include/asm/arch-exynos5/exynos-cpufreq.h >>>> > ./arch/arm/include/asm/arch-exynos5/exynos-tmu.h >>>> > ./arch/arm/dts/exynos5250.dtsi >>>> > ./arch/arm/dts/exynos-periph-id.dtsi >>>> > ./arch/arm/cpu/armv7/exynos5/exynos_cache.c >>>> > >>>> > u-boot-vos # find . -type f -name "arndale*" >>>> > >>>> > For sure I can't use a newer version of u-boot because otherwise the >>>> patches needed to bypass the bootloader protections >>>> > of the Arm Chromebook (such as a lot of different patches needed to >>>> boot correctly Linux) will be broken ; anyway,since >>>> > it works,I don't need to use an updated version of u-boot. >>>> > >>>> > ----> As per my experience, you have to respect these two options, >>>> compiling u-boot for >>>> > FreeBSD: >>>> https://github.com/freebsd/freebsd-ports/blob/main/sysutils/u-boot-mas= ter/files/FreeBSD_Fragment >>>> > >>>> > It says that I should use these parameters : >>>> > >>>> > CONFIG_ARMV7_NONSEC=3Dn >>>> > CONFIG_EFI_GRUB_ARM32_WORKAROUND=3Dy >>>> > >>>> > These are the parameters used to configure a Linux kernel. I don't >>>> understand what's the relation between the compilation >>>> > of a linux kernel and u-boot. In the past I tried to recompile >>>> u-boot,but I didn't have the need to set up those >>>> > parameters,so I don't know how to do it (but I know how to recompile >>>> a Linux kernel). >>>> > >>>> > ---> I'm not sure that I'm getting you right, as I don't understand >>>> what you mean under "the first u-boot". >>>> > >>>> > >>>> > I'm talking about first u-boot because the whole procedure to boot >>>> Linux on the ARM Chromebook,that's explained here : >>>> > >>>> > >>>> http://www.virtualopensystems.com/en/solutions/guides/kvm-on-chromeboo= k/ >>>> > >>>> > >>>> > at some point they say : >>>> > >>>> > >>>> > To be able to run KVM on ARM platforms, the kernel has to be booted >>>> in hypervisor mode. Because of this relatively recent >>>> > requirement (due to the introduction of the virtualization >>>> extensions), up until now all booting methods would boot the >>>> > kernel in the standard Supervisor mode. >>>> > >>>> > For the ARM Chromebook the default boot procedure doesn't allow us t= o >>>> boot in hypervisor mode. Although the laptop's boot >>>> > mechanism is based on the frequently used u-boot, the binary is >>>> located in RO memory. Fortunately, a chained u-boot >>>> > mechanism can be used (i.e. starting another u-boot after the >>>> original). We can then enter hypervisor mode from our >>>> > custom iteration of u-boot and subsequently load our kernel and >>>> userspace. >>>> > >>>> > So,the first u-boot is the u-boot provided by virtual open >>>> systems,that's able to chainload the "u-boot binary located in >>>> > RO memory" , that does not boot Chrome OS in hypervisor mode. We >>>> don't need it if we want to boot Linux with kvm or xen >>>> > enabled. >>>> > >>>> > >>>> > On Sun, Dec 17, 2023 at 1:28=E2=80=AFAM Stanislav Silnicki < >>>> stanislav.silnicki@mailgate.us> wrote: >>>> > I'm not an expert in the topic, I only know, that ARM has >>>> divided hardware into two worlds - Secure and >>>> > Not-So, strictly limiting any software, running in non-secure >>>> world with access to functions and >>>> > resources. >>>> https://developer.arm.com/documentation/den0013/d/Security/TrustZone-h= ardware-architecture?lang=3Den >>>> >>>> > >>>> > I'm not sure, that I'm getting you right, as I don't understand what >>>> you mean under "the first u-boot". >>>> > >>>> > As I understand, virtualization (HYP) is running in non-secure world= ( >>>> https://developer.arm.com/documentation/ddi0406/c/System-Level-Archite= cture/The-System-Level-Programmers--Model/The-Virtualization-Extens >>>> > ions), so my guess (only guess!!!), virtualization software has to >>>> prepare (configure) HW platform in the way, >>>> > that FreeBSD kernel will not lack any resources, required to >>>> configure MPU, VA, etc. >>>> > So, if you lucky to boot virtualizer, which is aware of target OS, >>>> that maybe you can boot the kernel. Although, I >>>> > doubt, that you need to boot 'second' u-boot to boot the kernel - >>>> there is simply ubldr, which you can hook somehow >>>> > from virtualizer.... >>>> > >>>> > Stan >>>> > >>>> > >>>> > >>>> > Mario Marietto wrote: >>>> > >>>> > >>>> > ---> As I understand, it makes sure that u-boot keeps in secur= e >>>> mode during boot and passes control to >>>> > ubldr, which boots FreeBSD kernel, in that mode. >>>> > >>>> > Can you elaborate your sentence more ? I know that the bootloader >>>> secure mode is bypassed by the virtual open >>>> > systems u-boot. Are you saying that when the control passes to the >>>> second u-boot,it will happen in secure >>>> > mode,so that the bypass that happened loading the first u-boot,is >>>> annulled ? If this is true,maybe can I boot >>>> > FreeBSD using the virtual-open-system custom u-boot ? Is this >>>> compatible with FreeBSD ? Where can I find the >>>> > u-boot.bin that the xen developer talked about ? thanks bro'. >>>> > >>>> > >>>> > >>>> > On Sun, Dec 17, 2023 at 12:35=E2=80=AFAM Stanislav Silnicki < >>>> stanislav.silnicki@mailgate.us> wrote: >>>> > Hi Mario, >>>> > >>>> > U-Boot beast is hiding in this den: >>>> https://source.denx.de/u-boot/u-boot.git >>>> > I took a brief look at your post and it seems to me, that >>>> option CONFIG_CMO_BY_VA_ONLY is irrelevant to >>>> > your target armv7 32 bit >>>> > platform: >>>> https://source.denx.de/u-boot/u-boot/-/blob/master/arch/arm/cpu/armv8/= Kconfig?ref_type=3Dheads#L3 >>>> > >>>> > As for compiling the u-boot, it is a doable task, given that you >>>> understand what you are doing. There >>>> > are no specific options in u-boot devoted to FreeBSD. It is a boot >>>> loader, whose mission to make basic >>>> > hardware initialization, read you kernel file from some media into >>>> RAM and then pass it control. >>>> > >>>> > Basically, you can grab some defconfig, prepared for any other >>>> Exynos5250 based board (say, this one: >>>> > >>>> https://source.denx.de/u-boot/u-boot/-/blob/master/configs/arndale_def= config?ref_type=3Dheads) >>>> and adopt >>>> > it somehow. >>>> > >>>> > As per my experience, you have to respect these two options, >>>> compiling u-boot for >>>> > FreeBSD: >>>> https://github.com/freebsd/freebsd-ports/blob/main/sysutils/u-boot-mas= ter/files/FreeBSD_Fragment >>>> > >>>> > As I understand, it makes sure, that u-boot keeps in secure mode >>>> during boot and passes control to >>>> > ubldr, which boots FreBSD kernel, in that mode. Otherwise, there a >>>> lot of surprises you may realize. >>>> > >>>> > Hope, this will help to progress you tasks >>>> > Stan >>>> > >>>> > Mario Marietto wrote: >>>> > >>>> > >>>> > Hello. >>>> > >>>> > I'm trying to boot FreeBSD for arm32 bit as DomU on my ARM >>>> Chromebook. Basically there are >>>> > two ways to accomplish this task : >>>> > >>>> > 1) to write a patch that allows the FreeBSD kernel to boot as = a >>>> zImage file. This could be >>>> > accomplished applying this patch to a specific file that's on >>>> the source code of FreeBSD : >>>> > >>>> > >>>> > >>>> https://xenbits.xen.org/gitweb/?p=3Dp...8;hb=3D0782e25d98cc13914727170= 35f986c979edef0c9 >>>> > >>>> > >>>> > This patch was written by Julien Grall a lot of time ago and >>>> now it does not work anymore. >>>> > This is the reason : >>>> > >>>> > >>>> > It appears FreeBSD-CURRENT removed the last step >>>> converting the kernel file to >>>> > kernel.bin. The patch can be readily rebased, but withou= t >>>> kernel.bin that >>>> > doesn't do too much >>>> > >>>> > >>>> > >>>> > So,without a rebase of that patch the first option is not applicable= . >>>> And I'm not able to fix it. >>>> > >>>> > 2) booting FreeBSD using U-Boot,as explained to me by a xen develope= r >>>> : >>>> > >>>> > >>>> > I was trying to explain why and how Julien's patch works so >>>> that you could be the one >>>> > to re-do something similar or fix the patch on the FreeBSD >>>> kernel that you are >>>> > working with. I am happy to help review and write patches but = I >>>> don't work with the >>>> > FreeBSD kernel so I wouldn't be able to help you quickly. >>>> However, I might have a >>>> > suggestion. Do you know if FreeBSD can be booted by U-Boot ? >>>> Because U-Boot >>>> > definitely boots as Xen on ARM guest firmware/bootloader. You >>>> should be able to build >>>> > U-Boot and use the U-Boot binary as Xen guest kernel, then >>>> U-Boot could load FreeBSD >>>> > from disk or network and start it. For instance as domU config >>>> file: >>>> > >>>> > kernel=3D"/home/petalinux/u-boot.bin" >>>> > disk =3D [ '/home/petalinux/test.img,raw,xvda' ] >>>> > >>>> > I know it is important to build u-boot with the following >>>> config to make it work on >>>> > Xen. >>>> > >>>> > CONFIG_CMO_BY_VA_ONLY=3Dy >>>> > >>>> > >>>> > >>>> > This option seems more doable to me according to my knowledge. But I >>>> need to understand how to do >>>> > it. >>>> > >>>> > Well,let's say that on the ARM Chromebook I'm forced to use and >>>> install a customized version of >>>> > u-boot,created by virtual open systems,because it is the only one >>>> that allows bypassing its >>>> > bootloader protection. You can find more information here : >>>> > >>>> > >>>> http://www.virtualopensystems.com/en/solutions/guides/kvm-on-chromeboo= k/?vos=3Dtech >>>> > >>>> > This is the relevant section to read : >>>> > >>>> > >>>> > Bootloader : >>>> > >>>> > If you wish to skip this chapter you can download a >>>> pre-compiled binary of the >>>> > bootloader: >>>> > >>>> > >>>> > $ wget >>>> > >>>> http://www.virtualopensystems.com/downloads/guides/kvm_on_chromebook/n= v_u-boot-snow.kpart >>>> > >>>> > >>>> > To be able to run KVM on ARM platforms, the kernel has to be >>>> booted in hypervisor >>>> > mode. Because of this relatively recent requirement (due to th= e >>>> introduction of the >>>> > virtualization extensions), up until now all booting methods >>>> would boot the kernel in >>>> > the standard Supervisor mode. For the ARM Chromebook the >>>> default boot procedure >>>> > doesn't allow us to boot in hypervisor mode. Although the >>>> laptop's boot mechanism is >>>> > based on the frequently used u-boot, the binary is located in >>>> RO memory. Fortunately, >>>> > a chained u-boot mechanism can be used (i.e. starting another >>>> u-boot after the >>>> > original). We can then enter hypervisor mode from our custom >>>> iteration of u-boot and >>>> > subsequently load our kernel and userspace. >>>> > >>>> > Checkout the needed u-boot code : >>>> > >>>> > >>>> > $ git clone git://github.com/virtualopensystems/u-boot.git$ cd >>>> u-boot$ >>>> > ./scripts/build.sh >>>> > >>>> > >>>> > If successful, a message about how to copy the bootloader on >>>> the USB flash disk or SD >>>> > card will appear. We will use it later when preparing the boot >>>> medium to start our >>>> > system. If you have followed the Setting up the boot medium >>>> chapter and you have a >>>> > prepared boot device, then you can update u-boot by running : >>>> > >>>> > >>>> > $ sudo dd if=3Dnv_uboot-snow.kpart of=3D/dev/sdX1 >>>> > >>>> > >>>> > >>>> > so,the needed u-boot that we must use should be installed on the >>>> first partition of the sd card. >>>> > >>>> > There is another relevant section to read : >>>> > >>>> > >>>> > Setting up the boot medium >>>> > >>>> > Now it is time to copy all the relevant files that we created >>>> in the previous >>>> > chapters,and use them to boot Chromebook with a different >>>> kernel and OS. In all these >>>> > examples the device /dev/sdX is used. Take extra care to chang= e >>>> the examples to the >>>> > device that you have attached. Insert the boot medium on your >>>> workstation and >>>> > carefully execute the following step. First we need to properl= y >>>> format the boot >>>> > medium. >>>> > >>>> > In the uboot source directory : >>>> > >>>> > >>>> > $ sudo ./scripts/sdcard.sh /dev/sdX >>>> > >>>> > >>>> > This will erase all data and create 4 partitions in the medium= , >>>> along with copying >>>> > the u-boot binary to the first partition: >>>> > >>>> > >>>> > Partition 1 =3D ChromeOS signed binary (V.O.S chained u-boot) >>>> > Partition 2 =3D not used >>>> > Partition 3 =3D EXT2 partition for u-boot files (uImage and >>>> exynos5250-snow.dtb) >>>> > Partition 4 =3D EXT4 partition for userspace files >>>> > >>>> > >>>> > With u-boot being copied, next is the kernel image and DTB >>>> file. From the kernel >>>> > source execute : >>>> > >>>> > >>>> > $ mkdir ../mnt/ >>>> > $ sudo mount /dev/sdX3 ../mnt/ >>>> > $ sudo cp arch/arm/boot/uImage ../mnt/ >>>> > $ sudo cp arch/arm/boot/dts/exynos5250-snow.dtb ../mnt/ >>>> > $ sudo umount /dev/sdX3 >>>> > >>>> > >>>> > Finally, we have to copy the Ubuntu userspace filesystem that >>>> we created earlier: >>>> > >>>> > >>>> > $ sudo mount /dev/sdX4 mnt/$ sudo cp -a ./precise/* mnt/$ sudo >>>> umount /dev/sdX4 >>>> > >>>> > >>>> > >>>> > Now,my idea is to chainload the already chain loaded u-boot created >>>> by V.O.S to the new u-boot >>>> > that we need for booting FreeBSD and that can be installed in the >>>> partition n.2,as shown in this >>>> > scheme,because it is not used : >>>> > >>>> > >>>> > Partition 1 =3D ChromeOS signed binary (V.O.S chained u-boot) >>>> > Partition 2 =3D not used (maybe we can install the u-boot for arm 32 >>>> bit,compatible with FreeBSD on >>>> > this partition) >>>> > Partition 3 =3D EXT2 partition for u-boot files (uImage and >>>> exynos5250-snow.dtb) >>>> > Partition 4 =3D EXT4 partition for userspace files >>>> > >>>> > >>>> > Take in consideration that default boot string is hardcoded here,in >>>> the snow.h file of the custom >>>> > u-boot created by VOS : >>>> > >>>> > >>>> > >>>> https://github.com/virtualopensyste...18a39b6c177dff58a/include/config= s/snow.h#L101 >>>> > >>>> > >>>> > and it needs to be recompiled because it should point to the >>>> partition n.2,where I will install >>>> > the u-boot files as explained here : >>>> > >>>> > >>>> > https://wiki.freebsd.org/arm/Chromebook >>>> > >>>> > >>>> > I have some questions to ask before I start working on this. >>>> > >>>> > 1) The xen developer said : >>>> > >>>> > >>>> > You should be able to build U-Boot and use the U-Boot binary a= s >>>> Xen guest kernel... >>>> > >>>> > >>>> > >>>> > where is the u-boot binary,according to this document ? >>>> > >>>> > https://wiki.freebsd.org/arm/Chromebook >>>> > >>>> > I don't see it. >>>> > >>>> > >>>> > 2) where is the source code of the file that I can get here : >>>> > >>>> > >>>> http://commondatastorage.googleapis.com/chromeos-localmirror/distfiles= /nv_uboot-snow-simplefb.kpart.bz2 >>>> > >>>> > I need the source code if I want to recompile u-boot so that it can >>>> point to the partition 4. >>>> > >>>> > Maybe it can be found on this link : >>>> > >>>> > http://linux-exynos.org/dist/chromebook/nv_uboot/ >>>> > >>>> > but it can't be opened.... >>>> > >>>> > >>>> > 3) in this specific scenario the source code of u-boot should run on >>>> arm 32 bit,not on arm >>>> > 64,because I have the Samsung Chromebook "SNOW" model XE303C12,that'= s >>>> powered by a Samsung Exynos >>>> > 5250 (ARMv7 32 bit Cortex A15) Soc. >>>> > >>>> > >>>> > 4) I'm not sure if I can chainload the customized u-boot created by >>>> V.O.S that should be >>>> > installed on the first partition with the u-boot tailored for bootin= g >>>> FreeBSD that should be >>>> > installed on the partition 2.... >>>> > >>>> > >>>> > 5) the xen developer said that u-boot should be compiled enabling >>>> this option : >>>> > >>>> > >>>> > Code: >>>> > >>>> > CONFIG_CMO_BY_VA_ONLY=3Dy >>>> > >>>> > >>>> > Well,can you provide some good source that can help me to understand >>>> how I can recompile u-boot >>>> > for FreeBSD ? thanks. >>>> > >>>> > -- >>>> > Mario. >>>> > >>>> > >>>> > >>>> > -- >>>> > Mario. >>>> > >>>> > >>>> > >>>> > -- >>>> > Mario. >>>> > >>>> > >>>> > >>>> > -- >>>> > Mario. >>>> > >>>> > >>>> > >>>> > -- >>>> > Mario. >>>> > >>>> > >>>> > >>>> > -- >>>> > Mario. >>>> > >>>> > >>> >>> >>> >>> -- >>> Mario. >>> >> >> --0000000000002bd665060cf90b00 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Warner,you didnt read one of my last email,where i said t= hat i have fixed that bug and I can boot my freebsd image with qemu and eve= n the network interface works well. I remember to you that my project is to= boot freebsd under xen. Thanks.

Il mer 20 dic 2023, 23:49 Warner Losh <<= a href=3D"mailto:imp@bsdimp.com">imp@bsdimp.com> ha scritto:


On W= ed, Dec 20, 2023 at 12:25=E2=80=AFAM titus <titus@edc.ro> wrote:
for the panic @ d= hcp see=C2=A0

its a problem with virtio= net driver (was fixed by forum user _martin but never went in the main tre= e)
if you emulate another nic type will work

Indeed it does.


should fix t= he problem. I think it's the right thing to do. It's what a lot of = other drivers do.

Warner
=C2=A0
On Dec 20, 2023, at 6:52 AM, Warner Losh <imp@bsdimp.com> wrote:

I'd = think you'd need the right virtualization loader. I'm not entirely = sure the u-boot.bin you've been creating is for a dom-u..=C2=A0
If I misunderstood, then the below isn't good advice. Chain booting = the u-boot, the first u-boot initializes things so you want
to st= art with stage after the SPL But the different error messages suggest that = it's trying to reboot with kexec, which
isn't supported o= n armv7 at the moment.

If you could boot in kv= m, I think that the following would work....=C2=A0 Though I'm not entir= ely sure how to
specify the two .fd files in your setup. The use = of qemu is to have an easy env to debug things... I don't
hav= e a chromebook to try...

My first instinct wou= ld be to try qemu on x86 (this is the first step of many to get to your des= tination).

If you could boot the GENERIC_SD image = that we produce using qemu + edk2-arm-code.fd that would
be a hug= e first step. This will give you the boot loader, I believe, to boot in the= VM that you need better
than going via the u-boot route. Since y= ou are booting in a virtualized environment, I think it wouldn't
<= div>matter which one :).

So, I did the following t= o boot the virtualized armv7 FreeBSD environment, following a post on the f= orums I found and knew to have the right recipe:

1. pkg install qemu
2. mkdir qemu-armv7-env
3. cd qe= mu-armv7-env
5. xz -d -T 0 FreeBSD-14.0-RELEASE-arm-armv7-GENERICSD.i= mg.xz
6. dd if=3D/dev/zero of=3Dpflash0.img bs=3D1m count=3D647. dd if=3D/dev/zero of=3Dpflash1.img bs=3D1m count=3D64
8. dd if=3D/us= r/local/share/qemu/edk2-arm-code.fd of=3Dpflash0.img conv=3Dnotrunc
9. d= d if=3D/usr/local/share/qemu/edk2-arm-vars.fd of=3Dpflash1.img conv=3Dnotru= nc
10. cat > start-freebsd-arm.sh
#!/bin/sh
qemu-= system-arm \
=C2=A0 -M virt \
=C2=A0 -m 1024 \
=C2=A0 -drive file= =3Dpflash0.img,format=3Draw,if=3Dpflash,readonly=3Don \
=C2=A0 -drive fi= le=3Dpflash1.img,format=3Draw,if=3Dpflash \
=C2=A0 -drive file=3D$1.img,= if=3Dvirtio,cache=3Dwritethrough \
=C2=A0 -nographic \
=C2=A0 -serial= mon:stdio
^D
11. chmod +x start-freebsd-arm.sh
12. ./start-freebsd-arm.sh FreeBSD-14.0-RELEASE-arm-armv7-GENERICSD

But I hit a snag with this on qemu 8.1.2 and 8.1.3 wi= th both 13.2 and 14.0:

Starting devd.
Starting = dhclient.
DHCPDISCOVER on vtnet0 to 255.255.255255 port 67 interval 7Fatal kernel mode data abort: 'Alignment Fault' on read
trapfra= me: 0xc4b36a60
FSR=3D00000001, FAR=3Ddd96701a, spsr=3D20000013
r0 =3D= 00000000, r1 =3D00000001, r2 =3D00000001, r3 =3Dc4b36b4c
r4 =3D00000014,= r5 =3Dd6618800, r6 =3Ddd96702e, r7 =3D0000022c
r8 =3D00000000, r9 =3D00= 00022c, r10=3Ddd96701a, r11=3Dc4b36b90
r12=3D4300ffff, ssp=3Dc4b36af0, s= lr=3Dc04a9728, pc =3Dc04a9750

panic: Fatal abort
cpuid =3D 0
t= ime =3D 1680843057
KDB: stack backtrace:
#0 0xc035786c at kdb_backtra= ce+0x48
#1 0xc02fdd20 at vpanic+0x140
#2 0xc02fdbe0 at vpanic+0
#3= 0xc06304ac at abort_align+0
#4 0xc063052c at abort_align+0x80
#5 0xc= 063017c at abort_handler+0x480
#6 0xc060f480 at exception_exit+0
#7 0= xc04a9750 at udp_input+0x288
#8 0xc0473f54 at ip_input+0x1e0
#9 0xc04= 447c0 at netisr_dispatch_src+0xf8
#10 0xc043bf2c at ether_demux+0x1a4#11 0xc043d5e4 at ether_nh_input+0x480
#12 0xc04447c0 at netisr_dispatc= h_src+0xf8
#13 0xc043c404 at ether_input+0x50
#14 0xc01c0838 at vtnet= _rx_vq_process+0x880
#15 0xc01b70d0 at vtpci_intx_intr+0xac
#16 0xc02= b87f0 at ithread_loop+0x2ec
#17 0xc02b465c at fork_exit+0xc0
Uptime: = 19s

I don't know if this is a problem with qem= u or FreeBSD's kernel...

Warner

On Tu= e, Dec 19, 2023 at 3:25=E2=80=AFPM Mario Marietto <marietto2008@gmai= l.com> wrote:
I've asked some help on the channel #arm on = Reddit and someone replied :

=

Maybe his answer can be useful to understand why it doe= s not work.

On Tue, Dec 19, 2023 at 8:33=E2=80=AFPM Stefano Stabe= llini <sstabellini@kernel.org> wrote:
+Michal

Hi Mario,

I am not sure about booting FreeBSD, but I am certain that u-boot works
fine as DomU kernel on ARMv8 (not sure about ARMv7). With this config
file:

name=3D"test"
kernel=3D"u-boot.bin"
extra =3D "console=3Dhvc0"
memory=3D256
vcpus=3D1
disk =3D [ 'FreeBSD-13.2-RELEASE-armv7.img,raw,xvda' ]

I don't know for sure if you can boot FreeBSD but you should definitely=
be able to see the u-boot command line prompt. The fact that you are
getting this message:

xc: error: panic: xg_dom_core.c:689: xc_dom_find_loader: no loader found: I= nvalid kernel

Means that something is not right in the u-boot configuration or u-boot
build. Michal and Artem (CCed) might know more. From what I recall,
there was nothing special required to get u-boot.bin to boot as domU
kernel, so now I wonder if it is an ARMv7 vs. ARMv8 issue.

Cheers,

Stefano


On Tue, 19 Dec 2023, Mario Marietto wrote:
> ....I see that some other interesting files have been produced by u-bo= ot when I have compiled it :
>
> u-boot
> u-boot.lds
> u-boot.bin
> u-boot.map
> u-boot-nodtb.bin
> u-boot.dtb
> u-boot.srec
> u-boot-dtb.bin
> u-boot.sym
>
> So,maybe I should use a different u-boot* file for booting FreeBSD ? >
>
> On Tue, Dec 19, 2023 at 4:28=E2=80=AFPM Mario Marietto <mariett= o2008@gmail.com> wrote:
>=C2=A0 =C2=A0 =C2=A0 =C2=A0Hello to everyone.
>
> I have compiled the needed u-boot.bin from scratch using this procedur= e :
>
> # git clone https://github.com/u-boot/u-boot.git=
> # cd u-boot
> # ARCH=3Darm CROSS_COMPILE=3Darm-linux-gnueabihf- make snow_defconfig = : this line generates the file .config
> # nano .config and I've added these parameters :
>
> CONFIG_ARMV7_NONSEC=3Dn
> CONFIG_EFI_GRUB_ARM32_WORKAROUND=3Dy
>
> the uboot-bin file is generated with this command :
>
> # ARCH=3Darm CROSS_COMPILE=3Darm-linux-gnueabihf- make
>
> At this point,I took a look inside the .config file and I saw that the= parameter "CONFIG_ARMV7_NONSEC=3Dn" has been removed. So,for
> some reason,it is not accepted and this could be a problem....
>
> These are the xen config files that I've used :
>
> nano freebsd.cfg
>
> name=3D"test"
> kernel=3D"u-boot.bin"
> extra =3D "console=3Dhvc0"
> memory=3D256
> vcpus=3D1
> disk =3D [ 'FreeBSD-13.2-RELEASE-armv7.img,raw,xvda' ]
>
> nano start-freebsd
>
> xl create freebsd.cfg
> xl console freebsd
>
> This is what happens when I launch the vm :
>
> # ./start-freebsd
> =C2=A0
> Parsing config from freebsd.cfg
> xc: error: panic: xg_dom_core.c:689: xc_dom_find_loader: no loader fou= nd: Invalid kernel
> libxl: error: libxl_dom.c:571:libxl__build_dom: xc_dom_parse_image fai= led
> libxl: error: libxl_create.c:1640:domcreate_rebuild_done: Domain 1:can= not (re-)build domain: -3
> libxl: error: libxl_domain.c:1183:libxl__destroy_domid: Domain 1:Non-e= xistent domain
> libxl: error: libxl_domain.c:1137:domain_destroy_callback: Domain 1:Un= able to destroy guest
> libxl: error: libxl_domain.c:1064:domain_destroy_cb: Domain 1:Destruct= ion of domain failed
> freebsd is an invalid domain identifier (rc=3D-6)
>
>
> On Mon, Dec 18, 2023 at 12:39=E2=80=AFPM Mario Marietto <mariet= to2008@gmail.com> wrote:
>=C2=A0 =C2=A0 =C2=A0 =C2=A0So,ok,I should have said "the second u-= boot" ; since the first u-boot binary is the "u-boot binary locat= ed in the RO
>=C2=A0 =C2=A0 =C2=A0 =C2=A0memory" of the Chromebook". Sorry = for the confusion.
>
> On Mon, Dec 18, 2023 at 12:35=E2=80=AFPM Mario Marietto <mariet= to2008@gmail.com> wrote:
>=C2=A0 =C2=A0 =C2=A0 =C2=A0---> There are no specific options in u-b= oot devoted to FreeBSD
>
> This is an important factor. So,what about if,instead of compiling a n= ew version of u-boot on the partition 2,I will
> recompile the u-boot customized version created by the virtual open sy= stem in 2014,that should be installed on the first
> partition ? It could work if there are no differences between the u-bo= ot that should boot Linux and the u-boot that
> should boot FreeBSD.
>
> Can you give a look at the u-boot source code created by virtual open = systems ? You can find it on my google drive :
>
> = https://drive.google.com/file/d/1eAaZMfd6CU0xiqQfH7sq5wGVzzO09BRm/view?usp= =3Dsharing
>
> I need to understand if I can recompile it without problem so that it = can satisfy my needs (the ability of the file
> u-boot.bin to boot FreeBSD as domU under Xen,as explained by Stefano S= tabellini,the xen developer that suggested to me
> what I could do to have FreeBSD virtualized under Xen on my Arm Chrome= book) ; otherwise the risk is to find later
> problems that will make me troubles and that I will not able to fix. >
> I gave a look at the virtual open system u-boot and I didn't see a= ny arndale_defconfig inside. So,If I have understood
> correctly,I should put that file inside the root of the u-boot source = code,let's say here :
>
> marietto:/home/marietto/Desktop/Files/u-boot_FreeBSD/u-boot-vos # ls > =C2=A0
> .checkpatch.conf =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0README =C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0doc =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= net
> .git =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0api =C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0drivers =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0onenand_ipl
> .gitignore =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0arch =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0dts =C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0post
> COPYING =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0board =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= examples =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0rules.mk
> CREDITS =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0boards.cfg =C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0fs =C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0scripts
> MAINTAINERS =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0common =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0include =C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0snapshot.commit
> MAKEALL =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0config.mk =C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0lib =C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0spl
> Makefile =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0cros =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= mkconfig =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0test
> PRESUBMIT.cfg =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0disk =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0nand_spl =C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= tools
>
> and I should do : make and make install ? and the file I need,u-boot.b= in will be generated ?=C2=A0
>
> I didn't find any pre made configuration file inside :
>
> u-boot-vos # find . -type f -name "exynos*"=C2=A0
>
> ./include/exynos-fb.h
> ./include/configs/exynos5-common.h
> ./doc/device-tree-bindings/spi/exynos-spi.txt
> ./doc/device-tree-bindings/usb/exynos-usb.txt
> ./drivers/power/exynos-tmu.c
> ./drivers/power/exynos-cpufreq.c
> ./drivers/video/exynos-fb.c
> ./drivers/spi/exynos_spi.c
> ./board/samsung/dts/exynos5250-spring.dts
> ./board/samsung/dts/exynos5250-smdk5250.dts
> ./board/samsung/dts/exynos5250-snow.dts
> ./board/samsung/dts/exynos5250-daisy.dts
> ./arch/arm/include/asm/arch-exynos5/exynos-cpufreq.h
> ./arch/arm/include/asm/arch-exynos5/exynos-tmu.h
> ./arch/arm/dts/exynos5250.dtsi
> ./arch/arm/dts/exynos-periph-id.dtsi
> ./arch/arm/cpu/armv7/exynos5/exynos_cache.c=C2=A0
>
> u-boot-vos # find . -type f -name "arndale*"
>
> For sure I can't use a newer version of u-boot because otherwise t= he patches needed to bypass the bootloader protections
> of the Arm Chromebook (such as a lot of different patches needed to bo= ot correctly Linux) will be broken ; anyway,since
> it works,I don't need to use an updated version of u-boot.
>
> ----> As per my experience, you have to respect these two options, = compiling u-boot for
> FreeBSD:=C2=A0https://github.com/freebsd/freebsd-ports/blob/mai= n/sysutils/u-boot-master/files/FreeBSD_Fragment
>
> It says that I should use these parameters :
>
> CONFIG_ARMV7_NONSEC=3Dn
> CONFIG_EFI_GRUB_ARM32_WORKAROUND=3Dy
>
> These are the parameters used to configure a Linux kernel. I don't= understand what's the relation between the compilation
> of a linux kernel and u-boot. In the past I tried to recompile u-boot,= but I didn't have the need to set up those
> parameters,so I don't know how to do it (but I know how to recompi= le a Linux kernel).
>
> ---> I'm not sure that I'm getting you right, as I don'= t understand what you mean under "the first u-boot".
>
>
> I'm talking about first u-boot because the whole procedure to boot= Linux on the ARM Chromebook,that's explained here :
>
> http://www.v= irtualopensystems.com/en/solutions/guides/kvm-on-chromebook/
>
>
> at some point they say :
>
>
> To be able to run KVM on ARM platforms, the kernel has to be booted in= hypervisor mode. Because of this relatively recent
> requirement (due to the introduction of the virtualization extensions)= , up until now all booting methods would boot the
> kernel in the standard Supervisor mode.
>
> For the ARM Chromebook the default boot procedure doesn't allow us= to boot in hypervisor mode. Although the laptop's boot
> mechanism is based on the frequently used u-boot, the binary is locate= d in RO memory. Fortunately, a chained u-boot
> mechanism can be used (i.e. starting another u-boot after the original= ). We can then enter hypervisor mode from our
> custom iteration of u-boot and subsequently load our kernel and usersp= ace.
>
> So,the first u-boot is the u-boot provided by virtual open systems,tha= t's able to chainload the "u-boot binary located in
> RO memory" , that does not boot Chrome OS in hypervisor mode. We = don't need it if we want to boot Linux with kvm or xen
> enabled.
>
>
> On Sun, Dec 17, 2023 at 1:28=E2=80=AFAM Stanislav Silnicki <stanislav.silnicki@mailgate.us> wrote:
>=C2=A0 =C2=A0 =C2=A0 =C2=A0I'm not an expert in the topic, I only k= now, that ARM has divided hardware into two worlds - Secure and
>=C2=A0 =C2=A0 =C2=A0 =C2=A0Not-So, strictly limiting any software, runn= ing in non-secure world with access to functions and
>=C2=A0 =C2=A0 =C2=A0 =C2=A0resources.=C2=A0https://developer.= arm.com/documentation/den0013/d/Security/TrustZone-hardware-architecture?la= ng=3Den
>
> I'm not sure, that I'm getting you right, as I don't under= stand what you mean under "the first u-boot".
>
> As I understand, virtualization (HYP) is running in non-secure world(<= a href=3D"https://developer.arm.com/documentation/ddi0406/c/System-Level-Ar= chitecture/The-System-Level-Programmers--Model/The-Virtualization-Extens" r= el=3D"noreferrer noreferrer" target=3D"_blank">https://developer.arm.com/do= cumentation/ddi0406/c/System-Level-Architecture/The-System-Level-Programmer= s--Model/The-Virtualization-Extens
> ions), so my guess (only guess!!!), virtualization software has to pre= pare (configure) HW platform in the way,
> that FreeBSD kernel will not lack any resources, required to configure= MPU, VA, etc.
> So, if you lucky to boot virtualizer, which is aware of target OS, tha= t maybe you can boot the kernel. Although, I
> doubt, that you need to boot 'second' u-boot to boot the kerne= l - there is simply ubldr, which you can hook somehow
> from virtualizer....
>
> Stan
>
>
>
> Mario Marietto wrote:
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0---> As I understand, it makes sure that = u-boot keeps in secure mode during boot and passes control to
>=C2=A0 =C2=A0 =C2=A0 =C2=A0ubldr, which boots FreeBSD kernel, in that m= ode.
>
> Can you elaborate your sentence more ? I know that the bootloader secu= re mode is bypassed by the virtual open
> systems u-boot. Are you saying that when the control passes to the sec= ond u-boot,it will happen in secure
> mode,so that the bypass that happened loading the first u-boot,is annu= lled ? If this is true,maybe can I boot
> FreeBSD using the virtual-open-system custom u-boot ? Is this compatib= le with FreeBSD ? Where can I find the
> u-boot.bin that the xen developer talked about ? thanks bro'.
>
>
>
> On Sun, Dec 17, 2023 at 12:35=E2=80=AFAM Stanislav Silnicki <stanislav.silnicki@mailgate.us> wrote:
>=C2=A0 =C2=A0 =C2=A0 =C2=A0Hi Mario,
>
> U-Boot=C2=A0 beast is hiding in this den: ht= tps://source.denx.de/u-boot/u-boot.git
> I took a brief look at your post and it seems to me, that option=C2=A0= CONFIG_CMO_BY_VA_ONLY=C2=A0is irrelevant to
> your target armv7 32 bit
> platform:=C2=A0https://source.denx.de/u-boot/u-boot/-/blob/mas= ter/arch/arm/cpu/armv8/Kconfig?ref_type=3Dheads#L3
>
> As for compiling the u-boot, it is a doable task, given that you under= stand what you are doing. There
> are no specific options in u-boot devoted to FreeBSD. It is a boot loa= der, whose mission to make basic
> hardware initialization, read you kernel file from some media into RAM= and then pass it control.
>
> Basically, you can grab some defconfig, prepared for any other Exynos5= 250 based board=C2=A0 (say, this one:
> https://source.denx.de/u-boot/u-boot/-/blob/master/configs/arndale= _defconfig?ref_type=3Dheads) and adopt
> it somehow.
>
> As per my experience, you have to respect these two options, compiling= u-boot for
> FreeBSD:=C2=A0https://github.com/freebsd/freebsd-ports/blob/mai= n/sysutils/u-boot-master/files/FreeBSD_Fragment
>
> As I understand, it makes sure, that u-boot keeps in secure mode durin= g boot and passes control to
> ubldr, which boots FreBSD kernel, in that mode. Otherwise, there a lot= of surprises you may realize.
>
> Hope, this will help to progress you tasks
> Stan
>
> Mario Marietto wrote:
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0Hello.
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0I'm trying to boot FreeBSD for arm32 bit= as DomU on my ARM Chromebook. Basically there are
>=C2=A0 =C2=A0 =C2=A0 =C2=A0two ways to accomplish this task :
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A01) to write a patch that allows the FreeBSD = kernel to boot as a zImage file. This could be
>=C2=A0 =C2=A0 =C2=A0 =C2=A0accomplished applying this patch to a specif= ic file that's on the source code of FreeBSD :
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0https://xenbits.xen.org/gitweb/?p=3Dp...8;hb= =3D0782e25d98cc1391472717035f986c979edef0c9
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0This patch was written by Julien Grall a lot= of time ago and now it does not work anymore.
>=C2=A0 =C2=A0 =C2=A0 =C2=A0This is the reason :
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0It appears FreeBSD-CURR= ENT removed the last step converting the kernel file to
>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0kernel.bin. The patch c= an be readily rebased, but without kernel.bin that
>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0doesn't do too much=
>
>
>
> So,without a rebase of that patch the first option is not applicable. = And I'm not able to fix it.
>
> 2) booting FreeBSD using U-Boot,as explained to me by a xen developer = :
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0I was trying to explain why and how Julien&#= 39;s patch works so that you could be the one
>=C2=A0 =C2=A0 =C2=A0 =C2=A0to re-do something similar or fix the patch = on the FreeBSD kernel that you are
>=C2=A0 =C2=A0 =C2=A0 =C2=A0working with. I am happy to help review and = write patches but I don't work with the
>=C2=A0 =C2=A0 =C2=A0 =C2=A0FreeBSD kernel so I wouldn't be able to = help you quickly. However, I might have a
>=C2=A0 =C2=A0 =C2=A0 =C2=A0suggestion. Do you know if FreeBSD can be bo= oted by U-Boot ? Because U-Boot
>=C2=A0 =C2=A0 =C2=A0 =C2=A0definitely boots as Xen on ARM guest firmwar= e/bootloader. You should be able to build
>=C2=A0 =C2=A0 =C2=A0 =C2=A0U-Boot and use the U-Boot binary as Xen gues= t kernel, then U-Boot could load FreeBSD
>=C2=A0 =C2=A0 =C2=A0 =C2=A0from disk or network and start it. For insta= nce as domU config file:
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0kernel=3D"/home/petalinux/u-boot.bin&qu= ot;
>=C2=A0 =C2=A0 =C2=A0 =C2=A0disk =3D [ '/home/petalinux/test.img,raw= ,xvda' ]
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0I know it is important to build u-boot with = the following config to make it work on
>=C2=A0 =C2=A0 =C2=A0 =C2=A0Xen.
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0CONFIG_CMO_BY_VA_ONLY=3Dy
>
>
>
> This option seems more doable to me according to my knowledge. But I n= eed to understand how to do
> it.
>
> Well,let's say that on the ARM Chromebook I'm forced to use an= d install a customized version of
> u-boot,created by virtual open systems,because it is the only one that= allows bypassing its
> bootloader protection. You can find more information here :
>
> h= ttp://www.virtualopensystems.com/en/solutions/guides/kvm-on-chromebook/?vos= =3Dtech
>
> This is the relevant section to read :
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0Bootloader :
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0If you wish to skip this chapter you can dow= nload a pre-compiled binary of the
>=C2=A0 =C2=A0 =C2=A0 =C2=A0bootloader:
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0$ wget
>=C2=A0 =C2=A0 =C2=A0 =C2=A0http://www.virtualopensystems.com/downloads/= guides/kvm_on_chromebook/nv_u-boot-snow.kpart
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0To be able to run KVM on ARM platforms, the = kernel has to be booted in hypervisor
>=C2=A0 =C2=A0 =C2=A0 =C2=A0mode. Because of this relatively recent requ= irement (due to the introduction of the
>=C2=A0 =C2=A0 =C2=A0 =C2=A0virtualization extensions), up until now all= booting methods would boot the kernel in
>=C2=A0 =C2=A0 =C2=A0 =C2=A0the standard Supervisor mode. For the ARM Ch= romebook the default boot procedure
>=C2=A0 =C2=A0 =C2=A0 =C2=A0doesn't allow us to boot in hypervisor m= ode. Although the laptop's boot mechanism is
>=C2=A0 =C2=A0 =C2=A0 =C2=A0based on the frequently used u-boot, the bin= ary is located in RO memory. Fortunately,
>=C2=A0 =C2=A0 =C2=A0 =C2=A0a chained u-boot mechanism can be used (i.e.= starting another u-boot after the
>=C2=A0 =C2=A0 =C2=A0 =C2=A0original). We can then enter hypervisor mode= from our custom iteration of u-boot and
>=C2=A0 =C2=A0 =C2=A0 =C2=A0subsequently load our kernel and userspace.<= br> >
>=C2=A0 =C2=A0 =C2=A0 =C2=A0Checkout the needed u-boot code :
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0$ git clone git://github.com/virtualopensystems/u-boot.git$ cd u-boot$
>=C2=A0 =C2=A0 =C2=A0 =C2=A0./scripts/build.sh
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0If successful, a message about how to copy t= he bootloader on the USB flash disk or SD
>=C2=A0 =C2=A0 =C2=A0 =C2=A0card will appear. We will use it later when = preparing the boot medium to start our
>=C2=A0 =C2=A0 =C2=A0 =C2=A0system. If you have followed the Setting up = the boot medium chapter and you have a
>=C2=A0 =C2=A0 =C2=A0 =C2=A0prepared boot device, then you can update u-= boot by running :
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0$ sudo dd if=3Dnv_uboot-snow.kpart of=3D/dev= /sdX1
>
>
>
> so,the needed u-boot that we must use should be installed on the first= partition of the sd card.
>
> There is another relevant section to read :
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0Setting up the boot medium
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0Now it is time to copy all the relevant file= s that we created in the previous
>=C2=A0 =C2=A0 =C2=A0 =C2=A0chapters,and use them to boot Chromebook wit= h a different kernel and OS. In all these
>=C2=A0 =C2=A0 =C2=A0 =C2=A0examples the device /dev/sdX is used. Take e= xtra care to change the examples to the
>=C2=A0 =C2=A0 =C2=A0 =C2=A0device that you have attached. Insert the bo= ot medium on your workstation and
>=C2=A0 =C2=A0 =C2=A0 =C2=A0carefully execute the following step. First = we need to properly format the boot
>=C2=A0 =C2=A0 =C2=A0 =C2=A0medium.
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0In the uboot source directory :
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0$ sudo ./scripts/sdcard.sh /dev/sdX
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0This will erase all data and create 4 partit= ions in the medium, along with copying
>=C2=A0 =C2=A0 =C2=A0 =C2=A0the u-boot binary to the first partition: >
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0Partition 1 =3D ChromeOS signed binary (V.O.= S chained u-boot)
>=C2=A0 =C2=A0 =C2=A0 =C2=A0Partition 2 =3D not used
>=C2=A0 =C2=A0 =C2=A0 =C2=A0Partition 3 =3D EXT2 partition for u-boot fi= les (uImage and exynos5250-snow.dtb)
>=C2=A0 =C2=A0 =C2=A0 =C2=A0Partition 4 =3D EXT4 partition for userspace= files
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0With u-boot being copied, next is the kernel= image and DTB file. From the kernel
>=C2=A0 =C2=A0 =C2=A0 =C2=A0source execute :
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0$ mkdir ../mnt/
>=C2=A0 =C2=A0 =C2=A0 =C2=A0$ sudo mount /dev/sdX3 ../mnt/
>=C2=A0 =C2=A0 =C2=A0 =C2=A0$ sudo cp arch/arm/boot/uImage ../mnt/
>=C2=A0 =C2=A0 =C2=A0 =C2=A0$ sudo cp arch/arm/boot/dts/exynos5250-snow.= dtb ../mnt/
>=C2=A0 =C2=A0 =C2=A0 =C2=A0$ sudo umount /dev/sdX3
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0Finally, we have to copy the Ubuntu userspac= e filesystem that we created earlier:
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0$ sudo mount /dev/sdX4 mnt/$ sudo cp -a ./pr= ecise/* mnt/$ sudo umount /dev/sdX4
>
>
>
> Now,my idea is to chainload the already chain loaded u-boot created by= V.O.S to the new u-boot
> that we need for booting FreeBSD and that can be installed in the part= ition n.2,as shown in this
> scheme,because it is not used :
>
>
> Partition 1 =3D ChromeOS signed binary (V.O.S chained u-boot)
> Partition 2 =3D not used (maybe we can install the u-boot for arm 32 b= it,compatible with FreeBSD on
> this partition)
> Partition 3 =3D EXT2 partition for u-boot files (uImage and exynos5250= -snow.dtb)
> Partition 4 =3D EXT4 partition for userspace files
>
>
> Take in consideration that default boot string is hardcoded here,in th= e snow.h file of the custom
> u-boot created by VOS :
>
>
> h= ttps://github.com/virtualopensyste...18a39b6c177dff58a/include/configs/snow= .h#L101
>
>
> and it needs to be recompiled because it should point to the partition= n.2,where I will install
> the u-boot files as explained here :
>
>
> https://wiki.freebsd.org/arm/Chromebook >
>
> I have some questions to ask before I start working on this.
>
> 1) The xen developer said :
>
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0You should be able to build U-Boot and use t= he U-Boot binary as Xen guest kernel...
>
>
>
> where is the u-boot binary,according to this document ?
>
> https://wiki.freebsd.org/arm/Chromebook >
> I don't see it.
>
>
> 2) where is the source code of the file that I can get here :
>
> http://commondatastorage.googleapis.com/chromeos-localmi= rror/distfiles/nv_uboot-snow-simplefb.kpart.bz2
>
> I need the source code if I want to recompile u-boot so that it can po= int to the partition 4.
>
> Maybe it can be found on this link :
>
> http://linux-exynos.org/dist/chrome= book/nv_uboot/
>
> but it can't be opened....
>
>
> 3) in this specific scenario the source code of u-boot should run on a= rm 32 bit,not on arm
> 64,because I have the Samsung Chromebook "SNOW" model XE303C= 12,that's powered by a Samsung Exynos
> 5250 (ARMv7 32 bit Cortex A15) Soc.
>
>
> 4) I'm not sure if I can chainload the customized u-boot created b= y V.O.S that should be
> installed on the first partition with the u-boot tailored for booting = FreeBSD that should be
> installed on the partition 2....
>
>
> 5) the xen developer said that u-boot should be compiled enabling this= option :
>
>
> Code:
>
> CONFIG_CMO_BY_VA_ONLY=3Dy
>
>
> Well,can you provide some good source that can help me to understand h= ow I can recompile u-boot
> for FreeBSD ? thanks.
>
> --
> Mario.
>
>
>
> --
> Mario.
>
>
>
> --
> Mario.
>
>
>
> --
> Mario.
>
>
>
> --
> Mario.
>
>
>
> --
> Mario.
>
>


--
Mario.

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