Re: Deprecate the ppc405 boards in QEMU?

[Thomas Huth]

On 05/10/2021 10.07, Thomas Huth wrote:
> On 05/10/2021 10.05, Alexey Kardashevskiy wrote:
[...]
> > What is so special about taihu?
>
> taihu is the other 405 board defined in hw/ppc/ppc405_boards.c (which I 
> suggested to deprecate now)

I've now also played with the u-boot sources a little bit, and with some bit 
of tweaking, it's indeed possible to compile the old taihu board there. 
However, it does not really work with QEMU anymore, it immediately triggers 
an assert():

$ qemu-system-ppc -M taihu -bios u-boot.bin -serial null -serial mon:stdio
**
ERROR:accel/tcg/tcg-accel-ops.c:79:tcg_handle_interrupt: assertion failed: 
(qemu_mutex_iothread_locked())
Aborted (core dumped)

Going back to QEMU v2.3.0, I can see at least a little bit of output, but it 
then also triggers an assert() during DRAM initialization:

$ qemu-system-ppc -M taihu -bios u-boot.bin -serial null -serial mon:stdio

Reset PowerPC core

U-Boot 2014.10-rc2-00123-g461be2f96e-dirty (Oct 05 2021 - 10:02:56)

CPU:   AMCC PowerPC 405EP Rev. B at 770 MHz (PLB=256 OPB=128 EBC=128)
       I2C boot EEPROM disabled
       Internal PCI arbiter enabled
       16 KiB I-Cache 16 KiB D-Cache
Board: Taihu - AMCC PPC405EP Evaluation Board
I2C:   ready
DRAM:  qemu-system-ppc: memory.c:1693: memory_region_del_subregion: 
Assertion `subregion->container == mr' failed.
Aborted (core dumped)

Not sure if this ever worked in QEMU, maybe in the early 0.15 time, but that 
version of QEMU also does not compile easily anymore on modern systems. So 
I'm afraid, getting this into a workable shape again will take a lot of 
time. At least I'll stop my efforts here now.

 Thomas