[PATCH v3 2/3] RISC-V: Minimal parser for "riscv, isa" strings

[Heiko Stübner]

Am Samstag, 12. Februar 2022, 07:30:00 CET schrieb Tsukasa OI:
> Current hart ISA ("riscv,isa") parser don't correctly parse:
> 
> 1. Multi-letter extensions
> 2. Version numbers
> 
> All ISA extensions ratified recently has multi-letter extensions
> (except 'H'). The current "riscv,isa" parser that is easily confused
> by multi-letter extensions and "p" in version numbers can be a huge
> problem for adding new extensions through the device tree.
> 
> Leaving it would create incompatible hacks and would make "riscv,isa"
> value unreliable.
> 
> This commit implements minimal parser for "riscv,isa" strings.  With this,
> we can safely ignore multi-letter extensions and version numbers.
> 
> Signed-off-by: Tsukasa OI <research_trasio at irq.a4lg.com>
> [Improved commit text and fixed a bug around 's' in base extension]
> Signed-off-by: Atish Patra <atishp at rivosinc.com>
> [Fixed workaround for QEMU]
> Signed-off-by: Tsukasa OI <research_trasio at irq.a4lg.com>

Tested-by: Heiko Stuebner <heiko at sntech.de>