Hi Ard, On 6/3/22 15:20, Huacai Chen wrote:
Add basic boot, setup and reset routines for LoongArch. Now, LoongArch machines use UEFI-based firmware. The firmware passes configuration information to the kernel via ACPI and DMI/SMBIOS. 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. The standard UEFI boot protocol (EFISTUB) will be added later. Cc: linux-efi@xxxxxxxxxxxxxxx Cc: Ard Biesheuvel <ardb@xxxxxxxxxx> Reviewed-by: WANG Xuerui <git@xxxxxxxxxx> Reviewed-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> Co-developed-by: Yun Liu <liuyun@xxxxxxxxxxx> Signed-off-by: Yun Liu <liuyun@xxxxxxxxxxx> Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
Would you please look at this patch, which has all the arch-independent changes backed out, and Ack if it is fit for mainlining?
I communicated a little with Huacai about the approach for supporting alternative boot protocols down the road, and we agreed to carry the respective changes downstream. And if needs truly arise for modifying common EFI logic, we can do so in a non-rushed manner later.
For the current status of the code, apparently it just accepts the standard efistub-shape FDT pointer from (whatever booting the image), and everything onwards are fully using the common code without modification as you can see from the diffstat. I rebased my BPI support patch on top of this (basically translating Loongson BPI data structures into the expected FDT form), and can confirm the boot can progress to the same point as before -- indeed the SVAM changes etc. are not necessary for a working system, and the code remains working.
Thanks in advance.
