[PATCH] libc: arm: setjmp jmp_buf exagerated size
Wed Feb 15 16:12:04 GMT 2023
On 15/02/2023 11:09, Bernhard Krug wrote:
> Patch sets correct jmp_buf size for armv6-m conforming to implementation in setjmp.S
> FYI a table of cortex architectures:
> __ARM_ARCH_6M__ cortex-m0/m0+/m1 no fpu option
> __ARM_ARCH_7M__ cortex-m3 no fpu option
> __ARM_ARCH_7EM__ cortex-m4 optional fpu
> check using __ARM_FP
I don't think it's as simple as this. The ABI supports three variants,
two of which are call compatible.
hard-float (where you must have hardware FP)
soft (where you haven't got any hardware FP)
softfp (where you have hardware FP but need to inter-operate with code
soft and softfp are call compatible and so any jump-bufs created need to
support saving and restoring the FP context.
I guess a configure-time option to disable support for softfp might be
an option, but the default needs to ensure things are compatible.
More information about the Newlib