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Re: [Qemu-devel] [PATCH] openrisc: terminate qemu process upon receiving
From: |
Richard Henderson |
Subject: |
Re: [Qemu-devel] [PATCH] openrisc: terminate qemu process upon receiving a halt signal. |
Date: |
Fri, 03 Apr 2015 13:41:52 -0700 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 |
On 04/02/2015 09:50 AM, Hesham ALMatary wrote:
> or1ksim simulator currently handles "l.nop 0xC" instruction as
> a halt signal. Do the same for QEMU.
>
> Signed-off-by: Hesham ALMatary <address@hidden>
> ---
> target-openrisc/translate.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/target-openrisc/translate.c b/target-openrisc/translate.c
> index dc76789..5fa8ede 100644
> --- a/target-openrisc/translate.c
> +++ b/target-openrisc/translate.c
> @@ -750,6 +750,11 @@ static void dec_misc(DisasContext *dc, uint32_t insn)
> switch (op1) {
> case 0x01: /* l.nop */
> LOG_DIS("l.nop %d\n", I16);
> +
> + if(I16 == 0xC) {
> + exit(0);
> + }
> +
Ug. IMO l.nop was a poor choice; l.trap would have been better.
But whatever...
Further:
(1) This is translation time, not execution time. You can't do
the exit here, only when the instruction is executed.
(2) This, and the other 10 things hidden under l_nop are
similar to the "-semihosting" switch available for arm,
lm32, m68k, and xtensa.
Although semihosting is typically even more complex,
generally implementing the exit/read/write/open/close/lseek/stat
families of syscalls.
r~