Re: [PATCH] s3: wake up on RTC event

[Gleb Natapov <gleb@redhat.com>]

On Tue, Mar 05, 2013 at 10:16:18AM +0100, Paolo Bonzini wrote:
> The S3 test requires user interaction to terminate.  Set up the
> RTC alarm instead, so that the test will end after one second.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Heh, nice!

> ---
>  x86/s3.c | 36 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
> 
> diff --git a/x86/s3.c b/x86/s3.c
> index d7df92d..30634bb 100644
> --- a/x86/s3.c
> +++ b/x86/s3.c
> @@ -127,6 +127,32 @@ u32* find_resume_vector_addr(void)
>     return 0;
>  }
>  
> +#define RTC_SECONDS_ALARM       1
> +#define RTC_MINUTES_ALARM       3
> +#define RTC_HOURS_ALARM         5
> +#define RTC_ALARM_DONT_CARE     0xC0
> +
> +#define RTC_REG_A               10
> +#define RTC_REG_B               11
> +#define RTC_REG_C               12
> +
> +#define REG_A_UIP               0x80
> +#define REG_B_AIE               0x20
> +
> +static inline int rtc_in(u8 reg)
> +{
> +    u8 x = reg;
> +    asm volatile("outb %b1, $0x70; inb $0x71, %b0"
> +		 : "+a"(x) : "0"(x));
> +    return x;
> +}
> +
> +static inline void rtc_out(u8 reg, u8 val)
> +{
> +    asm volatile("outb %b1, $0x70; mov %b2, %b1; outb %b1, $0x71"
> +		 : "+a"(reg) : "0"(reg), "ri"(val));
> +}
> +
>  extern char resume_start, resume_end;
>  
>  int main(int argc, char **argv)
> @@ -140,6 +166,16 @@ int main(int argc, char **argv)
>  	for (addr = &resume_start; addr < &resume_end; addr++)
>  		*resume_vec++ = *addr;
>  	printf("copy resume code from %x\n", &resume_start);
> +
> +	/* Setup RTC alarm to wake up on the next second.  */
> +	while ((rtc_in(RTC_REG_A) & REG_A_UIP) == 0);
> +	while ((rtc_in(RTC_REG_A) & REG_A_UIP) != 0);
> +	rtc_in(RTC_REG_C);
> +	rtc_out(RTC_SECONDS_ALARM, RTC_ALARM_DONT_CARE);
> +	rtc_out(RTC_MINUTES_ALARM, RTC_ALARM_DONT_CARE);
> +	rtc_out(RTC_HOURS_ALARM, RTC_ALARM_DONT_CARE);
> +	rtc_out(RTC_REG_B, rtc_in(RTC_REG_B) | REG_B_AIE);
> +
>  	*(volatile int*)0 = 0;
>  	asm volatile("out %0, %1" :: "a"(0x2400), "d"((short)0xb004):"memory");
>  	while(1)
> -- 
> 1.8.1.2
> 
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--
			Gleb.