Hi Rob,

On Wed, Jan 18, 2023 at 5:50 AM Rob Landley [off-list ref] wrote:

On 1/17/23 14:26, Geert Uytterhoeven wrote:

quoted

On Tue, Jan 17, 2023 at 8:01 PM Rob Landley [off-list ref] wrote:

quoted

I'm lazy and mostly test each new sh4 build under qemu -M r2d because it's
really convenient: neither of my physical boards boot from SD card so replacing
the kernel requires reflashing soldered in flash. (They'll net mount userspace
but I haven't gotten either bootloader to net-boot a kernel.)

On my landisk (with boots from CompactFLASH), I boot the original 2.6.22
kernel, and use kexec to boot-test each and every renesas-drivers
release.  Note that this requires both the original 2.6.22 kernel
and matching kexec-tools.

I make it a point to run _current_ kernels in all my mkroot systems, including
sh4. What I shipped was 6.1 is:

# cat /proc/version
Linux version 6.1.0 (landley@driftwood) (sh4-linux-musl-cc (GCC) 9.4.0, GNU ld
(GNU Binutils) 2.33.1) #1 Tue Jan 10 16:32:07 CST 2023

I think you misunderstood: renesas-drivers releases[1] are current
kernels.

   Linux version 6.2.0-rc3-landisk-01864-g0c6453b3e5f6 (geert@rox)
(sh4-linux-gnu-gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0, GNU ld (GNU
Binutils for Ubuntu) 2.38) #125 Tue Jan 10 14:29:01 CET 2023

I use 2.6.22 and kexec as a boot loader for newer kernels, to avoid
juggling CF cards.  I cannot install a newer base kernel on the CF,
as kexec is broken upstream.

quoted

Apparently both upstreamed kernel and
kexec-tools support for SH are different, and incompatible with each
other, so you cannot kexec from a contemporary kernel.

Sure you can. Using toybox's insmod and modprobe, anyway. (That's the target I
tested those on... :)

Haven't messed with signing or compression or anything yet, my insmod is just
doing syscall(SYS_finit_module) and then falling back to SYS_init_module if that
fails and either fd was 0 or errno was ENOSYS. (Don't ask me why
SYS_finit_module doesn't work on stdin...)

https://github.com/landley/toybox/blob/master/toys/other/insmod.c#L31

https://landley.net/toybox/downloads/binaries/0.8.9/toybox-sh4

Again, I think you're talking about something different.
Does kexec work for you?

quoted

I tried working my way up from 2.6.22, but gave up around 2.6.29.
Probably I should do this with r2d and qemu instead ;-)

I have current running there. I've had current running there for years. Config
attached...

quoted

Both r2d and landisk are SH7751.

Cool. Shouldn't be hard to get landisk running current then.

Current kernels work fine on landisk with an old Debian userspace
on CF.  The 8139cp driver is a bit flaky: last time I tried nfsroot,
that didn't work well.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds