[PATCH v2] riscv: Fix detecting FPU support in standard extension

[Rick Chen]

> From: U-Boot <u-boot-bounces at lists.denx.de> On Behalf Of Yu Chien Peter Lin
> Sent: Saturday, November 05, 2022 2:02 PM
> To: u-boot at lists.denx.de
> Cc: samuel at sholland.org; Peter Yu-Chien Lin(林宇謙) <peterlin at andestech.com>
> Subject: [PATCH v2] riscv: Fix detecting FPU support in standard extension
>
> We should check the string until it hits underscore, in case it searches for the letters in the custom extension. For example, "rv64imac_xandes" will be treated as D extension support since there is a "d" in "andes", resulting illegal instruction caused by initializing FCSR.
>
> Signed-off-by: Yu Chien Peter Lin <peterlin at andestech.com>
> ---
>  arch/riscv/cpu/cpu.c | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)

Reviewed-by: Rick Chen <rick at andestech.com>