[PATCH v6 3/3] riscv: fix building compressed EFI image

[David Laight]

On Sat, 25 Apr 2026 21:51:50 +0300
Dmitry Antipov <dmantipov at yandex.ru> wrote:

> When building vmlinuz.efi with CONFIG_EFI_ZBOOT enabled,
> '__lshrdi3()' is also needed to fix yet another link error:
> 
> riscv32-linux-gnu-ld: drivers/firmware/efi/libstub/lib-cmdline.stub.o: in function `__efistub_.L49':
> __efistub_cmdline.c:(.init.text+0x202): undefined reference to `__efistub___lshrdi3'
> 
> And since riscv64 can have CONFIG_EFI_ZBOOT but doesn't need
> these library routines, rely on CONFIG_32BIT to manage linking
> of lib-ashldi3.o and lib-lshrdi3.o on riscv32 only.
> 
> Reported-by: Charlie Jenkins <thecharlesjenkins at gmail.com>
> Closes: https://lore.kernel.org/linux-riscv/20260409050018.GA371560@inky.localdomain
> Tested-by: Charlie Jenkins <thecharlesjenkins at gmail.com>
> Suggested-by: Ard Biesheuvel <ardb at kernel.org>
> Signed-off-by: Dmitry Antipov <dmantipov at yandex.ru>
> ---
> v6: adjust to match recent upstream changes
> v5: rely on CONFIG_32BIT rather than dedicated Kconfig symbol (Ard)
> v4: use more meaningful CONFIG_EFI_ZBOOT_USE_LIBGCC and adjust tags (Andy)
> v3: initial version to join the series
> ---
>  drivers/firmware/efi/libstub/Makefile | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
> index 983a438e35f3..e1c11d02a5cb 100644
> --- a/drivers/firmware/efi/libstub/Makefile
> +++ b/drivers/firmware/efi/libstub/Makefile
> @@ -95,7 +95,9 @@ CFLAGS_zboot-decompress-gzip.o	+= -I$(srctree)/lib/zlib_inflate
>  zboot-obj-$(CONFIG_KERNEL_ZSTD)	:= zboot-decompress-zstd.o lib-xxhash.o
>  CFLAGS_zboot-decompress-zstd.o	+= -I$(srctree)/lib/zstd
>  
> -zboot-obj-$(CONFIG_RISCV)	+= lib-clz_ctz.o lib-ashldi3.o
> +zboot-obj-$(CONFIG_RISCV)	+= lib-clz_ctz.o
> +zboot-riscv-obj-$(CONFIG_32BIT)	+= lib-ashldi3.o lib-lshrdi3.o
> +zboot-obj-$(CONFIG_RISCV)	+= lib-clz_ctz.o $(zboot-riscv-obj-y)

Doesn't that specify lib-clz_ctz.o twice ?
I think you could also use:
zboot-obj-$(CONFIG_RISCV)	+= lib-clz_ctz.o $(if $(CONFIG_32BIT),lib-ashldi3.o lib-lshrdi3.o)

	David

>  zboot-obj-$(CONFIG_LOONGARCH)	+= lib-clz_ctz.o lib-ashldi3.o
>  lib-$(CONFIG_EFI_ZBOOT)		+= zboot.o $(zboot-obj-y)
>