Date: Mon, 21 Jan 2019 14:59:20 +0200 From: Toomas Soome <tsoome@me.com> To: "lev@freebsd.org" <lev@FreeBSD.org> Cc: Warner Losh <imp@bsdimp.com>, Rebecca Cran <bcran@freebsd.org>, FreeBSD Current <freebsd-current@freebsd.org> Subject: Re: GPT boot has less features than legacy MBR-based one (Was: UEFI, loader.efi and /boot.config) Message-ID: <C7DBCEA9-42AE-4ACC-84D8-10035DF0529E@me.com> In-Reply-To: <b4100160-d30d-a696-a2cb-be4f7f0d5305@FreeBSD.org> References: <912985968.20190119125228@serebryakov.spb.ru> <etPan.5c433dd9.327b23c6.1973@bluestop.org> <1951151017.20190119235425@serebryakov.spb.ru> <4636753.YNO7O01DYZ@photon.int.bluestop.org> <17710465740.20190120134042@serebryakov.spb.ru> <CANCZdfq%2BmuSr=CX4V9_ebWwNv1S49=mJZms0ZVoCB2onp%2BqHNA@mail.gmail.com> <3f4214e2-36af-cc87-0a3c-2c7ce26cffd8@FreeBSD.org> <DE6A295D-80CF-4E9A-88EE-F9F63ED66286@me.com> <b4100160-d30d-a696-a2cb-be4f7f0d5305@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
> On 21 Jan 2019, at 14:45, Lev Serebryakov <lev@FreeBSD.org> wrote: >=20 > On 21.01.2019 15:39, Toomas Soome wrote: >=20 >>>> Is too complicated? Boot1.efi doesn't allow that, but loader.efi = does. >>> loader.efi lives on ESP partition, do I understand it right? So, it >>> could not be damaged with "bad" upgrade? >>=20 >> It could, unless the backup is created.=20 > Does it live on code (root) FS or ESP? I understand, that when you > upgrade ESP partition, you could ruin it, but typically root FS is > upgraded much more often than ESP/boot0/boot1 parts. >=20 > --=20 > // Lev Serebryakov >=20 If you are using boot1.efi, the loader.efi is in OS /boot/loader.efi = annd boot1.efi is stored to ESP and will execute loader.efi as bios = boot2 programs do. As UEFI does not *replace* the program which did call StartImage() but = both do stay in memory (so you have both boot1.efi and loader.efi in = memory), and boot1.efi does not add any significant features, we will = drop boot1.efi (it is already dropped in illumos btw), and will only use = loader.efi - and in this case, the loader.efi is installed to ESP and = will only start the kernel. This also does mean that in ideal world, the update should create backup = of boot program in ESP (this actually also does apply to boot1.efi), but = the default ESP created by FreeBSD used to be too small for that. With normal systems it should not be an issue because you can always = boot from usb stick/cd (image), but with embedded systems it may be = significant issue. But then again, if you are using stock (generic) OS = on embedded system, you are already doing it wrong and will get into the = trouble sooner or later:) rgds, toomas=
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?C7DBCEA9-42AE-4ACC-84D8-10035DF0529E>