From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stafford Horne Date: Thu, 28 Apr 2022 20:55:51 +0900 Subject: [OpenRISC] [PATCH] openrisc: define nop command for simulator reboot In-Reply-To: <20220428111139.1330966-1-Jason@zx2c4.com> References: <20220428111139.1330966-1-Jason@zx2c4.com> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: openrisc@lists.librecores.org On Thu, Apr 28, 2022 at 01:11:39PM +0200, Jason A. Donenfeld wrote: > The simulator defines `l.nop 1` for shutdown, but doesn't have anything > for reboot. Use 13 for this, which is currently unused, dubbed > `NOP_REBOOT`. > > Cc: Stafford Horne > Cc: Peter Maydell > Link: https://lore.kernel.org/all/YmnaDUpVI5ihgvg6 at zx2c4.com/ > Signed-off-by: Jason A. Donenfeld > --- > arch/openrisc/kernel/process.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c > index 3c0c91bcdcba..4cce95fa6eb5 100644 > --- a/arch/openrisc/kernel/process.c > +++ b/arch/openrisc/kernel/process.c > @@ -52,6 +52,8 @@ void machine_restart(char *cmd) > { > do_kernel_restart(cmd); > > + __asm__("l.nop 13"); > + > /* Give a grace period for failure to restart of 1s */ > mdelay(1000); > > -- > 2.35.1 This seems fair, probably it would be good to have a comment mentioninmg what the nop is for, fyi for context these are the nop numbers used to control simulations. #define NOP_NOP 0x0000 /* Normal nop instruction */ #define NOP_EXIT 0x0001 /* End of simulation */ #define NOP_REPORT 0x0002 /* Simple report */ /*#define NOP_PRINTF 0x0003 Simprintf instruction (obsolete)*/ #define NOP_PUTC 0x0004 /* JPB: Simputc instruction */ #define NOP_CNT_RESET 0x0005 /* Reset statistics counters */ #define NOP_GET_TICKS 0x0006 /* JPB: Get # ticks running */ #define NOP_GET_PS 0x0007 /* JPB: Get picosecs/cycle */ #define NOP_TRACE_ON 0x0008 /* Turn on tracing */ #define NOP_TRACE_OFF 0x0009 /* Turn off tracing */ #define NOP_RANDOM 0x000a /* Return 4 random bytes */ #define NOP_OR1KSIM 0x000b /* Return non-zero if this is Or1ksim */ #define NOP_EXIT_SILENT 0x000c /* End of simulation, quiet version */ /* New! */ #define NOP_RESET 0x000d /* Reset the cpu */ I will queue this once we update the spec to define some of these, I am thinking if qemu should allow for the shutdown to work in user mode. BTW, are you working specifically on openrisc? Or just setting up test environments for all architectures? Acked-by: Stafford Horne