[PATCH 0/2] Fix MIPS/Malta target and its IDE work

[Daniel Schwierzeck]

Am Montag, den 22.02.2021, 20:56 +0100 schrieb Reinoud Zandijk:
> Hi Daniel,
> 
> On Mon, Feb 22, 2021 at 07:23:26PM +0100, Daniel Schwierzeck wrote:
> > Am Montag, den 22.02.2021, 18:05 +0100 schrieb Reinoud Zandijk:
> > > Patch 0001 re-enables FDT inclusion into the u-boot binary to
> > > make
> > > them boot
> > > again. The code might not have adjusted well enough in the past
> > > to
> > > handle the
> > > separate one.
> > 
> > what exactly is the issue? Do you see it just on real hardware?
> > 
> > Booting all Malta variants in Qemu is contained in official U-Boot
> > CI
> > and showed no boot failures until now. Unfortuneately I don't have
> > Malta hardware myself for testing.
> 
> If I remove it, the machine just spins in Qemu, no output, nothing.
> If I add
> it, it works fine again. I found out by bisecting. I have no idea why
> the
> tests aren't picking this up. Could it be a qemu/gcc/binutils
> combination
> issue? A symbol not set as expected?
> 
> qemu 5.1.0
> gcc 8.3.0
> binutils 2.32
> 

which board config did you try exactly? malta or maltael?

For maltael and malta64el an extra U-Boot binary named u-boot-swap.bin
is generated which is booted with Qemu. See also [1] respectively all
conf.malta*_qemu configs for working Qemu configurations for all Malta
variants.

The reason for that extra image is that the original MIPS YAMON loader
builds a combined EB/EL image and links it to EB. With some assembly
magic the start code determines immediately after the reset vector
which endianess the CPU is running and branches to the according EB or
LE image. This is replicated in the Qemu Malta machine implementation.
The Malta EL machine code excepts a bootloader in EB format and swaps
the code back to EL before executing it. To workaround this, we need to
feed this u-boot-swap.bin to Qemu.

[1] 
https://gitlab.denx.de/u-boot/u-boot-test-hooks/-blob/master/bin/travis-ci/conf.maltael_qemu

-- 
- Daniel