tree a11c718536c722e7400a10d96302196896e7ebd6
parent 3260a35d35b85b82b892b7439ccc62ffe9f8709a
author Andre Przywara <andre.przywara@arm.com> 1742729736 +0000
committer Andre Przywara <andre.przywara@arm.com> 1743035195 +0000

sunxi: update rmr_switch.S source code

Because the Allwinner BootROM always runs in AArch32, even on ARMv8 SoCs,
we need to switch to AArch64 first, but also need to save the CPU state,
when we later may need to return to the BootROM, for continuing with the
FEL USB protocol. This is done in 32-bit code, which we include into the
AArch64 boot assembly file as a series of .word directives, containing
the encoded AArch32 instructions. To be able to change and verify that
code, we also kept an assembly file with the respective 32-bit code, but
just for reference.

As this code is never compiled or assembled - it's just for
documentation - it became stale over time: we didn't really update this
along with the changes we made to the boot code. In particular the FEL
save code was completely missing.

Update that 32-bit assembly file, to match the current version used in
boot0.h, including the FEL save routine. Also update the build
instructions in the comments, to give people an actual chance to
assemble this code.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>