[PATCH v6] kexec-tools: mips: Pass initrd parameter via cmdline

[Simon Horman]

On Sat, Jun 25, 2022 at 10:49:49AM +0800, Hui Li wrote:
> Under loongson platform, use command:
> kexec -l vmlinux... --append="root=UUID=28e1..." --initrd=...
> kexec -e
> quick restart failed like this:
> 
> ********************************************************************
> [    3.420791] VFS: Cannot open root device "UUID=6462a8a4-02fb-49..."
> [    3.431262] Please append a correct "root=" boot option; ...
> ...
> ...
> ...
> [    3.543175]   0801         4194304 sda1 554e69cc-01
> [    3.543175]
> [    3.549494]   0802        62914560 sda2 554e69cc-02
> [    3.549495]
> [    3.555818]   0803         8388608 sda3 554e69cc-03
> [    3.555819]
> [    3.562139]   0804       174553229 sda4 554e69cc-04
> [    3.562139]
> [    3.568463] 0b00         1048575 sr0
> [    3.568464]  driver: sr
> [    3.574524] Kernel panic - not syncing: VFS: Unable to mount root fs...
> [    3.582750] ---[ end Kernel panic - not syncing: VFS:...
> *******************************************************************
> 
> The kernel cannot parse the UUID, the UUID is parsed in the initrd.
> For compatibility with previous platforms, loongson platform obtain
> initrd parameter through cmdline in kernel, the kernel supports use
> cmdline to parse initrd. But under the mips architecture, kexec-tools
> pass the initrd through DTB.
> 
> Made the following modifications:
> 
> (1) in kexec/arch/mips/kexec-elf-mips.c
>     Add patch_initrd_info(), at runtime to distinguish different cpu,
>     only for loongson cpu, add initrd parameter to cmdline.
> 
> (2) in kexec/arch/mips/crashdump-mips.c
>     Because loongson uses a different page_offset, it should be modified
>     to ensure that crashdump functionality is correct and reliable.
> 
> (3) in kexec/arch/mips/crashdump-mips.h
>     Added platform-specific page_offset macro definition.
> 
> Signed-off-by: Hui Li <lihui at loongson.cn>

Thanks for addressing all my review comments.
I have applied this patch for inclusion in the next release
of kexec-tools.