Re: [PATCH V11 09/22] LoongArch: Add boot and setup routines

From: Xi Ruoyao
Date: Tue May 24 2022 - 04:35:26 EST


On Wed, 2022-05-18 at 17:26 +0800, Huacai Chen wrote:
> Currently an existing interface between the kernel and the bootloader
> is  implemented. Kernel gets 2 values from the bootloader, passed in
> registers a0 and a1; a0 is an "EFI boot flag" distinguishing UEFI and
> non-UEFI firmware, while a1 is a pointer to an FDT with systable,
> memmap, cmdline and initrd information.

If I understand this correctly, we can:

- set a0 to 0
- set a1 a pointer (virtual address or physical address?) to the FDT
with these information

in the bootloader before invoking the kernel, then it will be possible
to boot this kernel w/o firmware update?

I'd prefer to receive a firmware update anyway, but we need an
alternative if some vendor just say "no way, our customized distro works
fine and you should use it". (I'm not accusing LoongArch: such annoying
behavior is common among vendors of all architectures, and even worse
with x86 because they often say "just use Windoge".)
--
Xi Ruoyao <xry111@xxxxxxxxxxx>
School of Aerospace Science and Technology, Xidian University