Date: Mon, 18 Dec 2023 12:39:47 +0100 From: Mario Marietto <marietto2008@gmail.com> To: Stanislav Silnicki <stanislav.silnicki@mailgate.us> Cc: freebsd-arm@freebsd.org Subject: Re: How to boot FreeBSD for arm 32 bit as DomU with u-boot on my ARM Chromebook Message-ID: <CA%2B1FSijoPkRZRaU6tujaMJZeFd3CSyUN%2Bh4y0_NrrB5VWLgwpA@mail.gmail.com> In-Reply-To: <CA%2B1FSih7C0HEun99LHEwvyYRiH0PaLwwgnoQLHB69TWz2ykDZg@mail.gmail.com> References: <CA%2B1FSiit5NJ_W7f5mssivkGGLevXh_XmSB7ZxZbQe1dgev0_Pg@mail.gmail.com> <97aa980b9b44.6eb7f9d5c54e7@mailgate.us> <CA%2B1FSiheSwrO7Tz3F3Nmu4vcC2E=ONRX8nF3bhQGV0UDOFTrww@mail.gmail.com> <da024d1687f3a.2f0c601bba502@mailgate.us> <CA%2B1FSih7C0HEun99LHEwvyYRiH0PaLwwgnoQLHB69TWz2ykDZg@mail.gmail.com>
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--000000000000241867060cc737b6 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable 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 FreeBSD > > 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 customiz= ed > version created by the virtual open system in 2014,that should be install= ed > on the first partition ? It could work if there are no differences betwee= n > 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 open > systems ? You can find it on my google drive : > > > https://drive.google.com/file/d/1eAaZMfd6CU0xiqQfH7sq5wGVzzO09BRm/view?us= p=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 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 arnd= ale_defconfig > inside. So,If I have understood correctly,I should put that file inside t= he > root of the u-boot source 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-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 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-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 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 boo= t > 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 iteratio= n > 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 no= t > 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-har= dware-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-Architect= ure/The-System-Level-Programmers--Model/The-Virtualization-Extensions), >> so my guess (only guess!!!), virtualization software has to prepare >> (configure) HW platform in the way, that FreeBSD kernel will not lack an= y >> 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 ca= n >> hook somehow from virtualizer.... >> >> Stan >> >> >> >> Mario Marietto wrote: >> >> >> ---> As I understand, it makes sure that u-boot keeps in secure 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 annull= ed >> ? 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/K= config?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_defc= onfig?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-mast= er/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 mo= de. >>> 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=3D0782e25d98cc139147271703= 5f986c979edef0c9 >>> <https://xenbits.xen.org/gitweb/?p=3Dpeople/julieng/freebsd.git;a=3Dblo= b_plain;f=3Dsys/arm/conf/XENVIRT;h=3Dff6433392e6fc2d5fa7c1ad1f7c40155003af9= a8;hb=3D0782e25d98cc1391472717035f986c979edef0c9> >>> >>> >>> This patch was written by Julien Grall a lot of time ago and now it doe= s >>> 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 without >>> 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 developer : >>> >>> >>> 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 Fre= eBSD >>> 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 Xe= n on >>> ARM guest firmware/bootloader. You should be able to build U-Boot and u= se >>> the U-Boot binary as Xen guest kernel, then U-Boot could load FreeBSD f= rom >>> 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 mak= e >>> 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 ca= n >>> find more information here : >>> >>> >>> http://www.virtualopensystems.com/en/solutions/guides/kvm-on-chromebook= /?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/nv= _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 = the >>> introduction of the virtualization extensions), up until now all bootin= g >>> 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 afte= r >>> the original). We can then enter hypervisor mode from our custom iterat= ion >>> 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 th= e >>> 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 kern= el >>> and OS. In all these examples the device /dev/sdX is used. Take extra c= are >>> to change the examples to the device that you have attached. Insert the >>> boot medium on your workstation and carefully execute the following ste= p. >>> First we need to properly 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 create= d >>> 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 b= e >>> installed in the partition n.2,as shown in this scheme,because it is no= t >>> 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/configs= /snow.h#L101 >>> <https://github.com/virtualopensystems/u-boot/blob/eecfeb578e296ef3b739= ac918a39b6c177dff58a/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 : >>> >>> >>> You should be able to build U-Boot and use the 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-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 ar= m >>> 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 A= 15) >>> 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 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 ho= w >>> I can recompile u-boot for FreeBSD ? thanks. >>> >>> -- >>> Mario. >>> >>> >> >> -- >> Mario. >> >> > > -- > Mario. > --=20 Mario. --000000000000241867060cc737b6 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr">So,ok,I should have said "the second u-boot" ; s= ince the first u-boot binary is the "u-boot binary located in the RO m= emory" of the Chromebook". Sorry for the confusion.<br></div><br>= <div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Mon, De= c 18, 2023 at 12:35=E2=80=AFPM Mario Marietto <<a href=3D"mailto:mariett= o2008@gmail.com">marietto2008@gmail.com</a>> wrote:<br></div><blockquote= class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px so= lid rgb(204,204,204);padding-left:1ex"><div dir=3D"ltr"><div>---> There = are no specific options in u-boot devoted to=20 FreeBSD <br></div><div><br></div><div>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 sy= stem in 2014,that should be installed on the first partition ? It could wor= k if there are no differences between the u-boot that should boot Linux and= the u-boot that should boot FreeBSD.</div><div><br></div><div>Can you give= a look at the u-boot source code created by virtual open systems ? You can= find it on my google drive :<br></div><div><br></div><div><a href=3D"https= ://drive.google.com/file/d/1eAaZMfd6CU0xiqQfH7sq5wGVzzO09BRm/view?usp=3Dsha= ring" target=3D"_blank">https://drive.google.com/file/d/1eAaZMfd6CU0xiqQfH7= sq5wGVzzO09BRm/view?usp=3Dsharing</a></div><div><br></div><div>I need to un= derstand if I can recompile it without problem so that it can satisfy my ne= eds (the ability of the file u-boot.bin to boot FreeBSD as domU under Xen,a= s explained by Stefano Stabellini,the xen developer that suggested to me wh= at 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 an= d that I will not able to fix. <br></div><div><br></div><div>I gave a look = at the virtual open system u-boot and I didn't see any <span>arndale_de= fconfig inside. So,If I have understood correctly,I should put that file in= side the root of the u-boot source code,let's say here :</span></div><d= iv><strong><br></strong></div><div><font style=3D"font-family:arial,sans-se= rif" size=3D"2"><span style=3D"color:rgb(0,0,0);background-color:rgb(255,25= 5,255)">marietto:/home/marietto/Desktop/Files/u-boot_FreeBSD/u-boot-vos # l= s</span></font></div><div><font style=3D"font-family:arial,sans-serif" size= =3D"2"><span style=3D"color:rgb(0,0,0);background-color:rgb(255,255,255)">= =C2=A0</span><br>.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=A0net <br>.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 <br>.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 <br>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=A0exa= mples =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<a href=3D"http://rules.mk" target=3D"_blank">rules.mk= </a> <br>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 <br>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 <br>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=A0<a href=3D"http://config.mk" target=3D"_bl= ank">config.mk</a> =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 <br>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 <br>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=A0too= ls</font></div><div><font style=3D"font-family:arial,sans-serif" size=3D"2"= ><br></font></div><div><font style=3D"font-family:arial,sans-serif" size=3D= "2">and I should do : make and make install ? and the file I need,u-boot.bi= n will be generated ?=C2=A0</font></div><div><font style=3D"font-family:ari= al,sans-serif" size=3D"2"><br></font></div><div><font style=3D"font-family:= arial,sans-serif" size=3D"2">I didn't find any pre made configuration f= ile inside :<br></font></div><div><span style=3D"color:rgb(0,0,0);backgroun= d-color:rgb(255,255,255);font-family:arial,sans-serif"><br></span></div><di= v><span style=3D"color:rgb(0,0,0);background-color:rgb(255,255,255);font-fa= mily:arial,sans-serif">u-boot-vos # find . -type f -name "exynos*</spa= n><span style=3D"font-family:arial,sans-serif">"=C2=A0</span></div><di= v><span style=3D"font-family:arial,sans-serif"><br></span></div><div><span = style=3D"font-family:arial,sans-serif">./include/exynos-fb.h <br>./include/configs/exynos5-common.h <br>./doc/device-tree-bindings/spi/exynos-spi.txt <br>./doc/device-tree-bindings/usb/exynos-usb.txt <br>./drivers/power/exynos-tmu.c <br>./drivers/power/exynos-cpufreq.c <br>./drivers/video/exynos-fb.c <br>./drivers/spi/exynos_spi.c <br>./board/samsung/dts/exynos5250-spring.dts <br>./board/samsung/dts/exynos5250-smdk5250.dts <br>./board/samsung/dts/exynos5250-snow.dts <br>./board/samsung/dts/exynos5250-daisy.dts <br>./arch/arm/include/asm/arch-exynos5/exynos-cpufreq.h <br>./arch/arm/include/asm/arch-exynos5/exynos-tmu.h <br>./arch/arm/dts/exynos5250.dtsi <br>./arch/arm/dts/exynos-periph-id.dtsi <br>./arch/arm/cpu/armv7/exynos5/exynos_cache.c=C2=A0</span></div><div><spa= n style=3D"font-family:arial,sans-serif"><br></span></div><div><span style= =3D"font-family:arial,sans-serif">u-boot-vos # find . -type f -name "a= rndale*"</span><span style=3D"font-family:monospace"><br> <br></span></div><div><font style=3D"font-family:arial,sans-serif" size=3D"= 2">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.</font></div><div><font style=3D"font-family:arial,sans-serif" si= ze=3D"2"><br></font></div><div><div dir=3D"auto" id=3D"m_-27478780363695837= 02m_-2225904292843896452tmjah_g_1299">----> As per my experience, you ha= ve to respect=20 these two options, compiling u-boot for FreeBSD:=C2=A0<a href=3D"https://gi= thub.com/freebsd/freebsd-ports/blob/main/sysutils/u-boot-master/files/FreeB= SD_Fragment" target=3D"_blank">https://github.com/freebsd/freebsd-ports/blo= b/main/sysutils/u-boot-master/files/FreeBSD_Fragment</a></div><font style= =3D"font-family:arial,sans-serif" size=3D"2"></font></div><div><font size= =3D"4"><span style=3D"font-family:monospace"><br></span></font></div><div><= font size=3D"4"><span style=3D"font-family:monospace"></span></font></div><= div>It says that I should use these parameters :</div><div><br></div><div>C= ONFIG_ARMV7_NONSEC=3Dn<br>CONFIG_EFI_GRUB_ARM32_WORKAROUND=3Dy<font size=3D= "4"><br></font></div><div><font size=3D"4"><br></font></div><div><font size= =3D"2">These are the parameters used to configure a Linux kernel. I don'= ;t understand what's the relation between the compilation of a linux ke= rnel and u-boot. In the past I tried to recompile u-boot,but I didn't h= ave the need to set up those parameters,so I don't know how to do it (b= ut I know how to recompile a Linux kernel).</font><div dir=3D"auto" id=3D"m= _-2747878036369583702m_-962663937491960362tmjah_g_1299"><br></div><div dir= =3D"auto"><br></div><div dir=3D"auto">---> I'm not sure that I'm= getting you right, as I don't understand what you mean under "the= first u-boot".<p></p><p><br></p><p>I'm talking about first u-boot= because the whole procedure to boot Linux on the ARM Chromebook,that's= explained here :<br></p><p><a href=3D"http://www.virtualopensystems.com/en= /solutions/guides/kvm-on-chromebook/" target=3D"_blank">http://www.virtualo= pensystems.com/en/solutions/guides/kvm-on-chromebook/</a></p><p><br></p><p>= at some point they say :</p><p><br></p><p>To be able to run KVM on ARM plat= forms, the kernel has to be booted in hypervisor mode. Because of this relatively recent requirement (due to=20 the introduction of the virtualization extensions), up until now all=20 booting methods would boot the kernel in the standard Supervisor mode.</p> <p>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= =20 on the frequently used u-boot, the binary is located in RO memory.=20 Fortunately, a chained u-boot mechanism can be used (i.e. starting=20 another u-boot after the original). We can then enter hypervisor mode=20 from our custom iteration of u-boot and subsequently load our kernel and userspace.</p><p>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 do= n't need it if we want to boot Linux with kvm or xen enabled.</p></div>= </div></div><br><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_= attr">On Sun, Dec 17, 2023 at 1:28=E2=80=AFAM Stanislav Silnicki <<a hre= f=3D"mailto:stanislav.silnicki@mailgate.us" target=3D"_blank">stanislav.sil= nicki@mailgate.us</a>> wrote:<br></div><blockquote class=3D"gmail_quote"= style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);p= adding-left:1ex"><div><div> =20 =20 =20 =20 =20 =20 =20 <div id=3D"m_-2747878036369583702m_-5077711917547611557m_-962663937= 491960362compose-body-wrapper" dir=3D"auto"><div dir=3D"auto">I'm not a= n 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.=C2=A0<a href=3D"https:= //developer.arm.com/documentation/den0013/d/Security/TrustZone-hardware-arc= hitecture?lang=3Den" target=3D"_blank">https://developer.arm.com/documentat= ion/den0013/d/Security/TrustZone-hardware-architecture?lang=3Den</a></div><= div dir=3D"auto" id=3D"m_-2747878036369583702m_-5077711917547611557m_-96266= 3937491960362tmjah_g_1299"><br></div><div dir=3D"auto" id=3D"m_-27478780363= 69583702m_-5077711917547611557m_-962663937491960362tmjah_g_1299">I'm no= t sure, that I'm getting you right, as I don't understand what you = mean under "the first u-boot".</div><div dir=3D"auto" id=3D"m_-27= 47878036369583702m_-5077711917547611557m_-962663937491960362tmjah_g_1299"><= br></div><div dir=3D"auto" id=3D"m_-2747878036369583702m_-50777119175476115= 57m_-962663937491960362tmjah_g_1299">As I understand, virtualization (HYP) = is running in non-secure world (<a href=3D"https://developer.arm.com/docume= ntation/ddi0406/c/System-Level-Architecture/The-System-Level-Programmers--M= odel/The-Virtualization-Extensions" target=3D"_blank">https://developer.arm= .com/documentation/ddi0406/c/System-Level-Architecture/The-System-Level-Pro= grammers--Model/The-Virtualization-Extensions</a>), 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 configur= e MPU, VA, etc.</div><div dir=3D"auto" id=3D"m_-2747878036369583702m_-50777= 11917547611557m_-962663937491960362tmjah_g_1299">So, if you lucky to boot v= irtualizer, 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 virtual= izer....</div><div dir=3D"auto" id=3D"m_-2747878036369583702m_-507771191754= 7611557m_-962663937491960362tmjah_g_1299"><br></div><div dir=3D"auto" id=3D= "m_-2747878036369583702m_-5077711917547611557m_-962663937491960362tmjah_g_1= 299">Stan</div><div dir=3D"auto" id=3D"m_-2747878036369583702m_-50777119175= 47611557m_-962663937491960362tmjah_g_1299"><br></div><div dir=3D"auto" id= =3D"m_-2747878036369583702m_-5077711917547611557m_-962663937491960362tmjah_= g_1299"><br></div><br></div><div dir=3D"auto">Mario Marietto wrote:</div><b= r><br><div><blockquote type=3D"cite" style=3D"margin:0px 0px 0px 0.8ex;bord= er-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir=3D"ltr"><div>= ---> As=20 I understand, it makes sure that u-boot keeps in secure mode during boot=20 and passes control to ubldr, which boots FreeBSD kernel, in that mode.</div= ><div><br></div><div>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 happe= n 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-op= en-system custom u-boot ? Is this compatible with FreeBSD ? Where can I fin= d the u-boot.bin that the xen developer talked about ? thanks bro'. </d= iv><div><br></div><div><br></div></div><br><div class=3D"gmail_quote"><div = dir=3D"ltr" class=3D"gmail_attr">On Sun, Dec 17, 2023 at 12:35=E2=80=AFAM S= tanislav Silnicki <<a href=3D"mailto:stanislav.silnicki@mailgate.us" tar= get=3D"_blank">stanislav.silnicki@mailgate.us</a>> wrote:<br></div><bloc= kquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:= 1px solid rgb(204,204,204);padding-left:1ex"><div><div>=20 =20 =20 =20 =20 =20 =20 <div> =20 =20 =20 =20 =20 =20 =20 <div id=3D"m_-2747878036369583702m_-5077711917547611557m_-96266393= 7491960362m_5085590471051268986compose-body-wrapper" dir=3D"auto"><div dir= =3D"auto">Hi=20 Mario,</div><div dir=3D"auto"><br></div><div dir=3D"auto">U-Boot=C2=A0 beas= t is=20 hiding in this den: <a href=3D"https://source.denx.de/u-boot/u-boot.git" ta= rget=3D"_blank">https://source.denx.de/u-boot/u-boot.git</a></div><div dir= =3D"auto">I took a brief look at your post and it seems to me, that=20 option=C2=A0<span style=3D"font-family:SFMono-Regular,Menlo,Monaco,Consolas= ,"Liberation Mono","Courier New",monospace;font-size:in= herit">CONFIG_CMO_BY_VA_ONLY</span>=C2=A0is irrelevant to=20 your target armv7 32 bit=20 platform:=C2=A0<a href=3D"https://source.denx.de/u-boot/u-boot/-/blob/maste= r/arch/arm/cpu/armv8/Kconfig?ref_type=3Dheads#L3" target=3D"_blank">https:/= /source.denx.de/u-boot/u-boot/-/blob/master/arch/arm/cpu/armv8/Kconfig?ref_= type=3Dheads#L3</a></div><div dir=3D"auto" id=3D"m_-2747878036369583702m_-5= 077711917547611557m_-962663937491960362m_5085590471051268986tmjah_g_1299"><= br></div><div dir=3D"auto" id=3D"m_-2747878036369583702m_-50777119175476115= 57m_-962663937491960362m_5085590471051268986tmjah_g_1299">As=20 for compiling the u-boot, it is a doable task, given that you understand=20 what you are doing. There are no specific options in u-boot devoted to=20 FreeBSD. It is a boot loader, whose mission to make basic hardware=20 initialization, read you kernel file from some media into RAM and then pass= =20 it control. </div><div dir=3D"auto" id=3D"m_-2747878036369583702m_-50777119= 17547611557m_-962663937491960362m_5085590471051268986tmjah_g_1299"><br></di= v><div dir=3D"auto" id=3D"m_-2747878036369583702m_-5077711917547611557m_-96= 2663937491960362m_5085590471051268986tmjah_g_1299">Basically, you can grab = some defconfig,=20 prepared for any other Exynos5250 based board=C2=A0 (say, this one: <a href= =3D"https://source.denx.de/u-boot/u-boot/-/blob/master/configs/arndale_defc= onfig?ref_type=3Dheads)" target=3D"_blank">https://source.denx.de/u-boot/u-= boot/-/blob/master/configs/arndale_defconfig?ref_type=3Dheads)</a>=20 and adopt it somehow.</div><div dir=3D"auto" id=3D"m_-2747878036369583702m_= -5077711917547611557m_-962663937491960362m_5085590471051268986tmjah_g_1299"= ><br></div><div dir=3D"auto" id=3D"m_-2747878036369583702m_-507771191754761= 1557m_-962663937491960362m_5085590471051268986tmjah_g_1299">As per my exper= ience, you have to respect=20 these two options, compiling u-boot for FreeBSD:=C2=A0<a href=3D"https://gi= thub.com/freebsd/freebsd-ports/blob/main/sysutils/u-boot-master/files/FreeB= SD_Fragment" target=3D"_blank">https://github.com/freebsd/freebsd-ports/blo= b/main/sysutils/u-boot-master/files/FreeBSD_Fragment</a></div><div dir=3D"a= uto" id=3D"m_-2747878036369583702m_-5077711917547611557m_-96266393749196036= 2m_5085590471051268986tmjah_g_1299"><br></div><div dir=3D"auto" id=3D"m_-27= 47878036369583702m_-5077711917547611557m_-962663937491960362m_5085590471051= 268986tmjah_g_1299">As=20 I understand, it makes sure, that u-boot keeps in secure mode during boot= =20 and passes control to ubldr, which boots FreBSD kernel, in that mode.=20 Otherwise, there a lot of surprises you may realize.</div><div dir=3D"auto"= id=3D"m_-2747878036369583702m_-5077711917547611557m_-962663937491960362m_5= 085590471051268986tmjah_g_1299"><br></div><div dir=3D"auto" id=3D"m_-274787= 8036369583702m_-5077711917547611557m_-962663937491960362m_50855904710512689= 86tmjah_g_1299">Hope, this=20 will help to progress you tasks</div><div dir=3D"auto" id=3D"m_-27478780363= 69583702m_-5077711917547611557m_-962663937491960362m_5085590471051268986tmj= ah_g_1299">Stan</div><div dir=3D"auto" id=3D"m_-2747878036369583702m_-50777= 11917547611557m_-962663937491960362m_5085590471051268986tmjah_g_1299"><br><= /div></div><div dir=3D"auto">Mario=20 Marietto wrote:</div><br><br><div><blockquote type=3D"cite" style=3D"margin= :0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"= ><div dir=3D"ltr"><div><div><div><div id=3D"m_-2747878036369583702m_-507771= 1917547611557m_-962663937491960362m_5085590471051268986gmail-:1fg"><div id= =3D"m_-2747878036369583702m_-5077711917547611557m_-962663937491960362m_5085= 590471051268986gmail-:1ay"><div dir=3D"ltr">Hello.<br> <br> I'm trying to boot FreeBSD for arm32 bit as DomU on my ARM Chromebook.= =20 Basically there are two ways to accomplish this task :<br> <br> 1) to write a patch that allows the FreeBSD kernel to boot as a zImage=20 file. This could be accomplished applying this patch to a specific file=20 that's on the source code of FreeBSD :<br> <br> <br> <a href=3D"https://xenbits.xen.org/gitweb/?p=3Dpeople/julieng/freebsd.git;a= =3Dblob_plain;f=3Dsys/arm/conf/XENVIRT;h=3Dff6433392e6fc2d5fa7c1ad1f7c40155= 003af9a8;hb=3D0782e25d98cc1391472717035f986c979edef0c9" rel=3D"nofollow ugc= noopener" target=3D"_blank">https://xenbits.xen.org/gitweb/?p=3Dp...8;hb= =3D0782e25d98cc1391472717035f986c979edef0c9</a><br> <br> <br> This patch was written by Julien Grall a lot of time ago and now it does=20 not work anymore. This is the reason :<br> <br> <br> <blockquote> =09 <div> =09 <div> It appears FreeBSD-CURRENT removed the last step converting the=20 kernel file to kernel.bin. The patch can be readily rebased, but without kernel.bin that doesn't do too much. </div> =09 </div> </blockquote><br> <br> So,without a rebase of that patch the first option is not applicable. And= =20 I'm not able to fix it.<br> <br> 2) booting FreeBSD using U-Boot,as explained to me by a xen developer :<br> <br> <br> <blockquote> =09 <div> =09 <div> I was trying to explain why and how Julien's patch works so that you= =20 could be the one to re-do something similar or fix the patch on the=20 FreeBSD kernel that you are working with. I am happy to help review and=20 write patches but I don't work with the FreeBSD kernel so I wouldn'= t be=20 able to help you quickly. However, I might have a suggestion. Do you=20 know if FreeBSD can be booted by U-Boot ? Because U-Boot definitely=20 boots as Xen on ARM guest firmware/bootloader. You should be able to=20 build U-Boot and use the U-Boot binary as Xen guest kernel, then U-Boot=20 could load FreeBSD from disk or network and start it. For instance as=20 domU config file:<br> <br> kernel=3D"/home/petalinux/u-boot.bin"<br> disk =3D [ '/home/petalinux/test.img,raw,xvda' ]<br> <br> I know it is important to build u-boot with the following config to make it= =20 work on Xen.<br> <br> CONFIG_CMO_BY_VA_ONLY=3Dy </div> =09 </div> </blockquote><br> <br> This option seems more doable to me according to my knowledge. But I need= =20 to understand how to do it.<br> <br> Well,let's say that on the ARM Chromebook I'm forced to use and ins= tall a customized version of u-boot,created by virtual open systems,because it is the only one that allows bypassing its bootloader protection. You=20 can find more information here :<br> <br> <a href=3D"http://www.virtualopensystems.com/en/solutions/guides/kvm-on-chr= omebook/?vos=3Dtech" rel=3D"nofollow ugc noopener" target=3D"_blank">http:/= /www.virtualopensystems.com/en/solutions/guides/kvm-on-chromebook/?vos=3Dte= ch</a><br> <br> This is the relevant section to read :<br> <br> <br> <blockquote> =09 <div> =09 <div> Bootloader :<br> <br> If you wish to skip this chapter you can download a pre-compiled binary of= =20 the bootloader:<br> <br> <br> $ wget <a href=3D"http://www.virtualopensystems.com/downloads/guides/kvm_on= _chromebook/nv_u-boot-snow.kpart" rel=3D"nofollow ugc noopener" target=3D"_= blank">http://www.virtualopensystems.com/downloads/guides/kvm_on_chromebook= /nv_u-boot-snow.kpart</a><br> <br> <br> To be able to run KVM on ARM platforms, the kernel has to be booted in=20 hypervisor mode. Because of this relatively recent requirement (due to=20 the introduction of the virtualization extensions), up until now all=20 booting methods would boot the kernel in the standard Supervisor mode.=20 For the ARM Chromebook the default boot procedure doesn't allow us to= =20 boot in hypervisor mode. Although the laptop's boot mechanism is based= =20 on the frequently used u-boot, the binary is located in RO memory.=20 Fortunately, a chained u-boot mechanism can be used (i.e. starting=20 another u-boot after the original). We can then enter hypervisor mode=20 from our custom iteration of u-boot and subsequently load our kernel and userspace.<br> <br> Checkout the needed u-boot code :<br> <br> <br> $ git clone git://<a href=3D"http://github.com/virtualopensystems/u-boot.gi= t$" rel=3D"nofollow ugc=20 noopener" target=3D"_blank">github.com/virtualopensystems/u-boot.git$</a> c= d=20 u-boot$ ./scripts/build.sh<br> <br> <br> If successful, a message about how to copy the bootloader on the USB=20 flash disk or SD card will appear. We will use it later when preparing=20 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=20 can update u-boot by running :<br> <br> <br> $ sudo dd if=3Dnv_uboot-snow.kpart of=3D/dev/sdX1 </div> =09 </div> </blockquote><br> <br> so,the needed u-boot that we must use should be installed on the first=20 partition of the sd card.<br> <br> There is another relevant section to read :<br> <br> <br> <blockquote> =09 <div> =09 <div> Setting up the boot medium<br> <br> Now it is time to copy all the relevant files that we created in the=20 previous chapters,and use them to boot Chromebook with a different=20 kernel and OS. In all these examples the device /dev/sdX is used. Take=20 extra care to change the examples to the device that you have attached.=20 Insert the boot medium on your workstation and carefully execute the=20 following step. First we need to properly format the boot medium.<br> <br> In the uboot source directory :<br> <br> <br> $ sudo ./scripts/sdcard.sh /dev/sdX<br> <br> <br> This will erase all data and create 4 partitions in the medium, along with= =20 copying the u-boot binary to the first partition:<br> <br> <br> Partition 1 =3D ChromeOS signed binary (V.O.S chained u-boot)<br> Partition 2 =3D not used<br> Partition 3 =3D EXT2 partition for u-boot files (uImage and=20 exynos5250-snow.dtb)<br> Partition 4 =3D EXT4 partition for userspace files<br> <br> <br> With u-boot being copied, next is the kernel image and DTB file. From the= =20 kernel source execute :<br> <br> <br> $ mkdir ../mnt/<br> $ sudo mount /dev/sdX3 ../mnt/<br> $ sudo cp arch/arm/boot/uImage ../mnt/<br> $ sudo cp arch/arm/boot/dts/exynos5250-snow.dtb ../mnt/<br> $ sudo umount /dev/sdX3<br> <br> <br> Finally, we have to copy the Ubuntu userspace filesystem that we created=20 earlier:<br> <br> <br> $ sudo mount /dev/sdX4 mnt/$ sudo cp -a ./precise/* mnt/$ sudo umount=20 /dev/sdX4 </div> =09 </div> </blockquote><br> <br> Now,my idea is to chainload the already chain loaded u-boot created by=20 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=20 not used :<br> <br> <br> Partition 1 =3D ChromeOS signed binary (V.O.S chained u-boot)<br> Partition 2 =3D not used (maybe we can install the u-boot for arm 32=20 bit,compatible with FreeBSD on this partition)<br> Partition 3 =3D EXT2 partition for u-boot files (uImage and=20 exynos5250-snow.dtb)<br> Partition 4 =3D EXT4 partition for userspace files<br> <br> <br> Take in consideration that default boot string is hardcoded here,in the=20 snow.h file of the custom u-boot created by VOS :<br> <br> <br> <a href=3D"https://github.com/virtualopensystems/u-boot/blob/eecfeb578e296e= f3b739ac918a39b6c177dff58a/include/configs/snow.h#L101" rel=3D"nofollow ugc= noopener" target=3D"_blank">https://github.com/virtualopensyste...18a39b6c= 177dff58a/include/configs/snow.h#L101</a><br> <br> <br> and it needs to be recompiled because it should point to the partition=20 n.2,where I will install the u-boot files as explained here :<br> <br> <br> <a href=3D"https://wiki.freebsd.org/arm/Chromebook" rel=3D"nofollow ugc=20 noopener" target=3D"_blank">https://wiki.freebsd.org/arm/Chromebook</a><br>; <br> <br> I have some questions to ask before I start working on this.<br> <br> 1) The xen developer said :<br> <br> <br> <blockquote> =09 <div> =09 <div> You should be able to build U-Boot and use the U-Boot binary as Xen=20 guest kernel... </div> =09 </div> </blockquote><br> <br> where is the u-boot binary,according to this document ?<br> <br> <a href=3D"https://wiki.freebsd.org/arm/Chromebook" rel=3D"nofollow ugc=20 noopener" target=3D"_blank">https://wiki.freebsd.org/arm/Chromebook</a><br>; <br> I don't see it.<br> <br> <br> 2) where is the source code of the file that I can get here :<br> <br> <a rel=3D"nofollow ugc=20 noopener">http://commondatastorage.googleapis.com/chromeos-localmirror/dist= files/nv_uboot-snow-simplefb.kpart.bz2</a><br> <br> I need the source code if I want to recompile u-boot so that it can point= =20 to the partition 4.<br> <br> Maybe it can be found on this link :<br> <br> <a href=3D"http://linux-exynos.org/dist/chromebook/nv_uboot/" rel=3D"nofoll= ow=20 ugc noopener" target=3D"_blank">http://linux-exynos.org/dist/chromebook/nv_= uboot/</a><br> <br> but it can't be opened....<br> <br> <br> 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&quo= t; model XE303C12,that's powered by a Samsung Exynos 5250 (ARMv7 32 bit Cortex= =20 A15) Soc.<br> <br> <br> 4) I'm not sure if I can chainload the customized u-boot created by=20 V.O.S that should be installed on the first partition with the u-boot=20 tailored for booting FreeBSD that should be installed on the partition=20 2....<br> <br> <br> 5) the xen developer said that u-boot should be compiled enabling this=20 option :<br> <br> <br> =09 =09 <div> <div> Code: <br></div><div><br></div> <div dir=3D"ltr"> <pre dir=3D"ltr"><code>CONFIG_CMO_BY_VA_ONLY=3Dy</code></pre> </div> </div><br> <br> Well,can you provide some good source that can help me to understand how I= =20 can recompile u-boot for FreeBSD ?=20 thanks.</div></div></div></div></div></div><div><div><div><div id=3D"m_-274= 7878036369583702m_-5077711917547611557m_-962663937491960362m_50855904710512= 68986gmail-:1fh"><table role=3D"presentation"><tbody><tr><td><br></td><td><= /td></tr></tbody></table></div></div></div></div><span class=3D"gmail_signa= ture_prefix">-- </span><br><div dir=3D"ltr" class=3D"gmail_signature">Mario= .<br></div></div></blockquote></div> =20 =20 =20 </div> =20 =20 </div></div></blockquote></div><br clear=3D"all"><br><span class=3D"gmai= l_signature_prefix">-- </span><br><div dir=3D"ltr" class=3D"gmail_signature= ">Mario.<br></div></blockquote></div> =20 =20 =20 </div></div></blockquote></div><br clear=3D"all"><br><spa= n class=3D"gmail_signature_prefix">-- </span><br><div dir=3D"ltr" class=3D"= gmail_signature">Mario.<br></div> </blockquote></div><br clear=3D"all"><br><span class=3D"gmail_signature_pre= fix">-- </span><br><div dir=3D"ltr" class=3D"gmail_signature">Mario.<br></d= iv> --000000000000241867060cc737b6--
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