[PATCH] riscv: Add Zbb support for building U-Boot

[Leo Liang]

On Wed, Aug 09, 2023 at 06:49:30PM +0800, Yu Chien Peter Lin wrote:
> This patch adds ISA string to the -march to generate zbb instructions
> for U-Boot binaries, along with optimized string functions introduced
> from Linux kernel.
> 
> Signed-off-by: Yu Chien Peter Lin <peterlin at andestech.com>
> ---
>  arch/riscv/Kconfig              |  92 +++++++++++++++++++++++++++++
>  arch/riscv/Makefile             |   5 +-
>  arch/riscv/include/asm/string.h |  18 ++++++
>  arch/riscv/lib/Makefile         |   3 +
>  arch/riscv/lib/strcmp_zbb.S     |  81 +++++++++++++++++++++++++
>  arch/riscv/lib/strlen_zbb.S     | 101 ++++++++++++++++++++++++++++++++
>  arch/riscv/lib/strncmp_zbb.S    |  94 +++++++++++++++++++++++++++++
>  7 files changed, 393 insertions(+), 1 deletion(-)
>  create mode 100644 arch/riscv/lib/strcmp_zbb.S
>  create mode 100644 arch/riscv/lib/strlen_zbb.S
>  create mode 100644 arch/riscv/lib/strncmp_zbb.S

Reviewed-by: Leo Yu-Chi Liang <ycliang at andestech.com>