Re: Booting the FreeBSD kernel as an zImage file needs a patch upgrade ?.

[Mario Marietto <marietto2008@xxxxxxxxx>]

Anyway,the suggestion of @balanga didn't work. This is what happened
when I tried :

# mv /usr/src /usr/src-old
# cd /usr
# wget 
http://ftp-archive.freebsd.org/pub/FreeBSD-Archive/old-releases/i386/11.2-RELEASE/src.txz
# xz -d src.txz
# cd src
# make TARGET_ARCH=armv5 KERNCONF=CHROMEBOOK-SNOW buildworld buildkernel

make[1] : "/usr/src/Makefile.inc1" line 405 : unknown target armv5:armv5.
Error code 1.

On Tue, Jan 2, 2024 at 12:03 AM Mario Marietto <marietto2008@xxxxxxxxx> wrote:
>
> I still see too many variables in the equation. I need to eliminate
> some of them. So :
>
> 1) Do I need to patch the file locore-v6.S with the Julien's patch ?
> ---> 
> https://xenbits.xen.org/gitweb/?p=people/julieng/freebsd.git;a=commit;h=12a7cb346b88c6d3f52a20b98f361dc62797fbcd
>
> 2) What kind of u-boot are you talking about ? Where should I get it ?
>
> @balanga (a nice enthusiastic 'hacker') helped me to solve half part
> of the u-boot equation,giving to me this suggestion :
>
>
> "If you simply want me to extract :
>
> http://ftp-archive.freebsd.org/pub/FreeBSD-Archive/old-releases/i386/11.2-RELEASE/src.txz
>
> and run make TARGET_ARCH=armv5 KERNCONF=CHROMEBOOK-SNOW buildworld 
> buildkernel"
>
>
> so,theoretically in this way I have the ARMv5 rootfs (and the freebsd
> kernel file) that will boot with the proper version of u-boot,as has
> been explained here :
> https://forum.doozan.com/read.php?3,49039,136530#msg-136530
>
>
> "Whether you use "go" or "bootelf ", you will need to have some
> knowledge about what files are the kernel files in your ARMV5 rootfs.
> The BSD rootfs must be built for this architecture. And how to pass
> parameters to the kernel bootelf with API is more powerful, "go" is
> primitive"
>
>
> The other half part of the equation is related to u-boot. On the
> doozan forum has been explained that has been created the Kirkwood
> (Armv5) u-boot. I've asked the link where to grab it,because I could
> try to chainload "ubldr" using that version of u-boot with the ARMv5
> rootfs that balanga explained to me how to create.
>
> I could try,but I don't see the utility. Infact armV5 is dead as well
> as FreeBSD 11.2 for i386. I think that to follow the road of using
> u-boot for Kirkwood is a waste of time. I think that the right thing
> to do is to fix the main problems which FreeBSD is affected by : that
> it can't be booted as an zImage file by xen. It needs to be patched.
> And there are some missing hypercalls for arm32.
>
> Using u-boot for armV5 complicates things a lot and forces me to use a
> dead version of FreeBSD.
>
> On Mon, Jan 1, 2024 at 9:48 PM Warner Losh <imp@xxxxxxxxxx> wrote:
> >
> > So kernel.bin is expected to be loaded, by u-boot, using the 'load' command 
> > at a specific address. On arm, this can be any 2MB boundary. Once it is 
> > loaded, you jump to the _start address woth the 'go' command. The 
> > kernel.bin file doesn't have symbols, so you'll need to see where _start 
> > winds up at.
> >
> > So, let's say that the memory starts at 0x80000000 and _start is something 
> > like 0xc0000020 when you nm kernel | grep start you'd do something like:
> >
> > u-boot> load kernel.bin 0x80000000
> > u-boot> go 0x80000020
> >
> > Though I'm unsure what u-boot will read the kernel.bin from. Maybe xen can 
> > load it at a specific spot (and maybe your hunch is right that you can 
> > replace uboot with this binary... ive never xen booted like this so i don't 
> > know if you need the low level steps uboot preforms to be done or not). I 
> > suspect that it might and my info is just for raw hardware...
> >
> > Warner
> >
> > On Mon, Jan 1, 2024, 12:47 PM Mario Marietto <marietto2008@xxxxxxxxx> wrote:
> >>
> >> Thanks Warner. But the kernel.bin file should be used instead of the 
> >> u-boot file as bootloader ? and will it work as expected ? even if i have 
> >> patched the elliott code with the wrong patch ? thats because I havent a 
> >> working patch to use that can allow the frrebsd code to be threated as an 
> >> zImage file ?
> >>
> >> Il lun 1 gen 2024, 20:39 Warner Losh <imp@xxxxxxxxxx> ha scritto:
> >>>>
> >>>> Julien said that I could try to revert the commiting removing the step
> >>>> to create kernel.bin,but I don't know what it means,I don't know how
> >>>> to do that and I haven't found anyone who wants to explain to  me how
> >>>> to do it. And I'm not sure that it will be enough.
> >>>
> >>>
> >>> You need to add WITH_KERNEL_BIN for it to generate a kernel.bin file.
> >>> We turned that off by default since most people don't need/can't use that
> >>> file.
> >>>
> >>> Warner
>
>
>
> --
> Mario.



-- 
Mario.