since it is broken and inefficient, and then removed by:
commit dc961baaea
Author: chao.an <anchao@xiaomi.com>
Date: Thu Apr 14 18:07:14 2022 +0800
arm/armv7-[a|r]: move fpu save/restore to assembly handler
Save/Restore FPU registers in C environment is dangerous practive,
which cannot guarantee the compiler won't generate the assembly code
with float point registers, especially in interrupt handling
Signed-off-by: chao.an <anchao@xiaomi.com>
commit 8d66dbc068
Author: chao.an <anchao@xiaomi.com>
Date: Thu Apr 7 13:48:04 2022 +0800
arm/armv[7|8]-m: skip the fpu save/restore if stack frame is integer-only
Signed-off-by: chao.an <anchao@xiaomi.com>
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Drop to user-space in kernel/protected build with up_pthread_exit,
now all pthread_cleanup functions executed in user mode.
* A new syscall SYS_pthread_exit added
* A new tcb flag TCB_FLAG_CANCEL_DOING added
* up_pthread_exit implemented for riscv/arm arch
Signed-off-by: Huang Qi <huangqi3@xiaomi.com>