On Tue, 2015-02-10 at 20:15 +0800, Jeremy Kerr wrote: > We use r6 and r7 for epapr boot, but the current pre-C init will clobber > both of these. > > This change does a simple replacement, of r6 -> r12 and r7 -> r13, so > that we hit platform init with these registers intact. > > Signed-off-by: Jeremy Kerr <j...@ozlabs.org>
You might want to also remove the use of r8 and r9 which are supposed to contain the OPAL entry and base for debugging purposes. We would also have to restore them before booting the kernel. [ Note: kexec is also missing that ] Ben. > --- > arch/powerpc/boot/crt0.S | 24 ++++++++++++------------ > 1 file changed, 12 insertions(+), 12 deletions(-) > > diff --git a/arch/powerpc/boot/crt0.S b/arch/powerpc/boot/crt0.S > index bf8eeee..7e50211 100644 > --- a/arch/powerpc/boot/crt0.S > +++ b/arch/powerpc/boot/crt0.S > @@ -155,29 +155,29 @@ p_base: mflr r10 /* r10 now points to > runtime addr of p_base */ > ld r9,(p_rela-p_base)(r10) > add r9,r9,r10 > > - li r7,0 > + li r13,0 > li r8,0 > -9: ld r6,0(r11) /* get tag */ > - cmpdi r6,0 > +9: ld r12,0(r11) /* get tag */ > + cmpdi r12,0 > beq 12f /* end of list */ > - cmpdi r6,RELA > + cmpdi r12,RELA > bne 10f > - ld r7,8(r11) /* get RELA pointer in r7 */ > + ld r13,8(r11) /* get RELA pointer in r13 */ > b 11f > -10: addis r6,r6,(-RELACOUNT)@ha > - cmpdi r6,RELACOUNT@l > +10: addis r12,r12,(-RELACOUNT)@ha > + cmpdi r12,RELACOUNT@l > bne 11f > ld r8,8(r11) /* get RELACOUNT value in r8 */ > 11: addi r11,r11,16 > b 9b > 12: > - cmpdi r7,0 /* check we have both RELA and RELACOUNT */ > + cmpdi r13,0 /* check we have both RELA and RELACOUNT */ > cmpdi cr1,r8,0 > beq 3f > beq cr1,3f > > /* Calcuate the runtime offset. */ > - subf r7,r7,r9 > + subf r13,r13,r9 > > /* Run through the list of relocations and process the > * R_PPC64_RELATIVE ones. */ > @@ -185,10 +185,10 @@ p_base: mflr r10 /* r10 now points to > runtime addr of p_base */ > 13: ld r0,8(r9) /* ELF64_R_TYPE(reloc->r_info) */ > cmpdi r0,22 /* R_PPC64_RELATIVE */ > bne 3f > - ld r6,0(r9) /* reloc->r_offset */ > + ld r12,0(r9) /* reloc->r_offset */ > ld r0,16(r9) /* reloc->r_addend */ > - add r0,r0,r7 > - stdx r0,r7,r6 > + add r0,r0,r13 > + stdx r0,r13,r12 > addi r9,r9,24 > bdnz 13b > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
