Re: [Qemu-devel] [PULL 2/5] target/sh4: fix reset when using a kernel and an initrd

[Stefan Hajnoczi <stefanha@gmail.com>]

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On Mon, May 29, 2017 at 09:30:13PM +0200, Aurelien Jarno wrote:
> When a masked exception happens, the SH4 CPU generates a non-masked
> reset exception, which then jumps to the reset vector at address
> 0xA0000000. While this is emulated correctly in QEMU, this does not
> work when using a kernel and initrd as this address then contain an
> illegal instruction (and there is no guarantee the kernel and initrd
> haven't been overwritten).
> 
> Therefore call qemu_system_reset_request to reload the kernel and initrd
> and load the program counter to the kernel entry point.
> 
> Reviewed-by: Richard Henderson <rth@twiddle.net>
> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
> ---
>  target/sh4/helper.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/target/sh4/helper.c b/target/sh4/helper.c
> index 4c024f9529..5296e7cf4e 100644
> --- a/target/sh4/helper.c
> +++ b/target/sh4/helper.c
> @@ -21,6 +21,7 @@
>  #include "cpu.h"
>  #include "exec/exec-all.h"
>  #include "exec/log.h"
> +#include "sysemu/sysemu.h"
>  
>  #if !defined(CONFIG_USER_ONLY)
>  #include "hw/sh4/sh_intc.h"
> @@ -92,7 +93,14 @@ void superh_cpu_do_interrupt(CPUState *cs)
>  
>      if (env->sr & (1u << SR_BL)) {
>          if (do_exp && cs->exception_index != 0x1e0) {
> -            cs->exception_index = 0x000; /* masked exception -> reset */
> +            /* In theory a masked exception generates a reset exception,
> +               which in turn jumps to the reset vector. However this only
> +               works when using a bootloader. When using a kernel and an
> +               initrd, they need to be reloaded and the program counter
> +               should be loaded with the kernel entry point.
> +               qemu_system_reset_request takes care of that.  */
> +            qemu_system_reset_request();
> +            return;

The qemu_system_reset_request() prototype is changing.  There is a
conflict with another merged pull request.  Please rebase onto
https://github.com/stefanha/qemu.git staging.

target/sh4/helper.c:102:39: error: too few arguments to function call, single argument 'reason' was not specified
            qemu_system_reset_request();
            ~~~~~~~~~~~~~~~~~~~~~~~~~ ^

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