ppc rfi in head.s result in a reset?

ppc rfi in head.s result in a reset?

[wilbur.chan]

ppc 6xx

In platform_init function of  sandpoint.c , I delete the code of
getting command line from uboot, and set command_line to a fixed value
, which are like this:

            sandpoint.c-->  platform_init
                 #if 0
                 if (r3 && r6) {
		/* copy board info structure */
		memcpy( (void *)__res,(void *)(r3+KERNELBASE), sizeof(bd_t) );
		/* copy command line */
		*(char *)(r7+KERNELBASE) = 0;
		strcpy(cmd_line, (char *)(r6+KERNELBASE));
	}
                #endif
                strcpy(cmd_line, "xxx");


But I found that , when calling start_kernel in head.S (by rfi
instruction), the borad was reset into uboot, that is :

                li              r4,MSR_KERNEL
	FIX_SRR1(r4,r5)
	lis	r3,start_kernel@h
	ori	r3,r3,start_kernel@l
	mtspr	SPRN_SRR0,r3
	mtspr	SPRN_SRR1,r4
	SYNC
	RFI              //reset,why?


The RFI  instruction  here, caused the board reset to uboot.  Can
someone give me some advice on how could this happened?

Thank you

Re: ppc rfi in head.s result in a reset?

[Tonyliu]

wilbur.chan wrote:
> ppc 6xx
>
> In platform_init function of  sandpoint.c , I delete the code of
> getting command line from uboot, and set command_line to a fixed value
> , which are like this:
>
>             sandpoint.c-->  platform_init
>                  #if 0
>                  if (r3 && r6) {
> 		/* copy board info structure */
> 		memcpy( (void *)__res,(void *)(r3+KERNELBASE), sizeof(bd_t) );
> 		/* copy command line */
> 		*(char *)(r7+KERNELBASE) = 0;
> 		strcpy(cmd_line, (char *)(r6+KERNELBASE));
> 	}
>                 #endif
>                 strcpy(cmd_line, "xxx");
>
>   
Which version your kernel is ? I cant find sandpoint.c in powerpc git tree.
And I suspect it's conditional  "if (r3 && r6)" to copy cmd_line, and 
your change makes it unconditioned. Maybe it
will affect something.

Tony
> But I found that , when calling start_kernel in head.S (by rfi
> instruction), the borad was reset into uboot, that is :
>
>                 li              r4,MSR_KERNEL
> 	FIX_SRR1(r4,r5)
> 	lis	r3,start_kernel@h
> 	ori	r3,r3,start_kernel@l
> 	mtspr	SPRN_SRR0,r3
> 	mtspr	SPRN_SRR1,r4
> 	SYNC
> 	RFI              //reset,why?
>
>
> The RFI  instruction  here, caused the board reset to uboot.  Can
> someone give me some advice on how could this happened?
>
> Thank you
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev
>
>   


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