Hi Bin,
On Tue, 2018-11-13 at 00:22 -0800, Bin Meng wrote:
Allow U-Boot to run on hart 0 only, and suspend other harts.
With this change, '-smp n' works on QEMU RISC-V board.
Signed-off-by: Bin Meng bmeng.cn@gmail.com
arch/riscv/cpu/start.S | 4 ++++ 1 file changed, 4 insertions(+)
Reviewed-by: Lukas Auer lukas.auer@aisec.fraunhofer.de
I'll try to send my patch series with multi-hart support soon, so I hope we won't need this patch for long :)
diff --git a/arch/riscv/cpu/start.S b/arch/riscv/cpu/start.S index 9858058..fcb0466 100644 --- a/arch/riscv/cpu/start.S +++ b/arch/riscv/cpu/start.S @@ -46,6 +46,10 @@ _start: /* mask all interrupts */ csrw mie, zero
- csrr t0, mhartid
- beqz t0, call_board_init_f
+1: j 1b
To suspend the other harts, you can also add a WFI instruction before the jump instruction.
Thanks, Lukas
/*
- Set stackpointer in internal/ex RAM to call board_init_f
*/