[U-Boot] [PATCH] qemu-riscv64_smode, sifive-fu540: fix extlinux (define preboot)

[Bin Meng]

Hi,

On Thu, Dec 19, 2019 at 1:42 PM David Abdurachmanov
<david.abdurachmanov at gmail.com> wrote:
>
> On Thu, Dec 19, 2019 at 12:18 AM Vagrant Cascadian <vagrant at debian.org> wrote:
> >
> > On 2019-12-18, David Abdurachmanov wrote:
> > > On Wed, Dec 18, 2019 at 3:13 AM Vagrant Cascadian <vagrant at debian.org> wrote:
> > >>
> > >> On 2019-09-25, Vagrant Cascadian wrote:
> > >> > On 2019-08-21, David Abdurachmanov wrote:
> > >> >> Commit 37304aaf60bf92a5dc3ef222ba520698bd862a44 removed preboot
> > >> >> commands in RISC-V targets and broke extlinux support as reported
> > >> >> by Fu Wei <wefu at redhat.com>.
> > >> >>
> > >> >> The patch finishes migration of CONFIG_USE_PREBOOT and CONFIG_REBOOT
> > >> >> to Kconfig.
> > >> >
> > >> > Tested using qemu-riscv64_smode and it fixes extlinux booting. Thanks!
> > >> >
> > >> > Please CC me on future updates to the patch series.
> > >> >
> > >> > Tested-by: Vagrant Cascadian <vagrant at debian.org>
> > >>
> > >> This patch, or something like it, is still needed with u-boot
> > >> v2020.01-rc5 for extlinux support to load the device-tree from the boot
> > >> firmware.
> > >>
> > >> Is there a new approach in the works, or any chance to see something
> > >> like this get merged soon?
> > >
> > > I do carry several experiment patches in Fedora/RISCV, which I didn't
> > > yet sent for a review.
> > > Basically that allows me to boot a single Fedora/RISCV disk image on
> > > QEMU virt machine
> > > and SiFive Unleashed.
> > >
> > > See: http://fedora.riscv.rocks:3000/rpms/uboot-tools/src/branch/master-riscv64/uboot-tools.spec#L36
> > >
> > > Note some of the patches were merged in rc5.
> >
> > Thanks! I'll give your patches some testing when I get a chance.
> >
> >
> > Some potentially quite naive questions:
> >
> > > You would want the following two patches:
> > > http://fedora.riscv.rocks:3000/rpms/uboot-tools/src/branch/master-riscv64/riscv64-set-fdt_addr.patch
> >
> > Why does it need fdt_addr=0x88000000 need to be set (and to the same
> > value as fdt_addr_r)? According to README fdt_addr is for the flash
> > media, which I don't think is used in the qemu case, at least. Is
> > fdt_addr being (ab)used for some other purpose? I guess the README also
> > gives free reign to use the variables for other purposes... but it would
> > be good to know why that is needed vs. just using fdt_addr_r as
> > documented.
>
> The comments in uboot-tools.spec explain it.
> This is only needed if you use EXTLINUX to boot your image. IIRC
> EXTLINUX will assume DTB blob is available at fdt_addr or you can load
> one via fdt/fdtdir label in extlinux.conf (never tried).
> If you are booting in some other way you probably don't care about it.
>
> >
> >
> > > http://fedora.riscv.rocks:3000/rpms/uboot-tools/src/branch/master-riscv64/riscv-bootargs-preboot.patch
> >
> > CONFIG_PREBOOT="cp.l ${fdtcontroladdr} ${fdt_addr_r} 0x10000;"
>
> This used to solve memory corruption for DTB in v5.3 kernel IIRC. That
> was fixed in v5.4 kernel thus should be removed (I will test later).
>
> >
> > What does cp.l do?
> >
> > Do you need to force setting the console in CONFIG_BOOTARGS? It seemed
> > to autodetect the console on the installations I have running, possibly
> > getting the chosen console from device-tree?
>
> It doesn't detect it for me. Well it does on QEMU, but not on SiFive
> Unleashed. Both use different console (ttyS0 vs ttySIF0). I think the
> kernel doesn't look into chosen console expect powerpc IIRC.
>
> I can retest since this was added:
> https://github.com/torvalds/linux/commit/2993c9b04e616df0848b655d7202a707a70fc876
>
> I am updating kernel in Fedora/RISCV to 5.5-rc2 now thus I can
> re-check various patches again.
>

What's the status of this patch?

Regards,
Bin