On Wed, Sep 21, 2022 at 4:34 PM Chen Zhongjin <chenzhongjin@xxxxxxxxxx> wrote: > > Hi, > > On 2022/9/18 23:52, guoren@xxxxxxxxxx wrote: > > diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S > > index 5f49517cd3a2..426529b84db0 100644 > > --- a/arch/riscv/kernel/entry.S > > +++ b/arch/riscv/kernel/entry.S > > @@ -332,6 +332,33 @@ ENTRY(ret_from_kernel_thread) > > tail syscall_exit_to_user_mode > > ENDPROC(ret_from_kernel_thread) > > > > +#ifdef CONFIG_IRQ_STACKS > > +ENTRY(call_on_stack) > > + /* Create a frame record to save our ra and fp */ > > + addi sp, sp, -RISCV_SZPTR > > + REG_S ra, (sp) > > + addi sp, sp, -RISCV_SZPTR > > + REG_S fp, (sp) > > + > > + /* Save sp in fp */ > > + move fp, sp > > + > > + /* Move to the new stack and call the function there */ > > + li a3, IRQ_STACK_SIZE > > + add sp, a1, a3 > > + jalr a2 > > + > > + /* > > + * Restore sp from prev fp, and fp, ra from the frame > > + */ > > + move sp, fp > > + REG_L fp, (sp) > > + addi sp, sp, RISCV_SZPTR > > + REG_L ra, (sp) > > + addi sp, sp, RISCV_SZPTR > > + ret > > +ENDPROC(call_on_stack) > > +#endif > > Seems my compiler (riscv64-linux-gnu-gcc 8.4.0, cross compiling from > x86) cannot recognize the register `fp`. The whole entry.S uses s0 instead of fp, so I approve of your advice. Thx. > > After I changed it to `s0` this can pass compiling. > > > Seems there is nowhere else using `fp`, can this just using `s0` instead? > > Best, > > Chen > -- Best Regards Guo Ren
