diff options
Diffstat (limited to 'arch/powerpc/kernel/head_44x.S')
| -rw-r--r-- | arch/powerpc/kernel/head_44x.S | 42 |
1 files changed, 34 insertions, 8 deletions
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S index 5e12b741ba5f..f8e971ba94f5 100644 --- a/arch/powerpc/kernel/head_44x.S +++ b/arch/powerpc/kernel/head_44x.S @@ -93,6 +93,30 @@ _ENTRY(_start); bl early_init +#ifdef CONFIG_RELOCATABLE + /* + * r25 will contain RPN/ERPN for the start address of memory + * + * Add the difference between KERNELBASE and PAGE_OFFSET to the + * start of physical memory to get kernstart_addr. + */ + lis r3,kernstart_addr@ha + la r3,kernstart_addr@l(r3) + + lis r4,KERNELBASE@h + ori r4,r4,KERNELBASE@l + lis r5,PAGE_OFFSET@h + ori r5,r5,PAGE_OFFSET@l + subf r4,r5,r4 + + rlwinm r6,r25,0,28,31 /* ERPN */ + rlwinm r7,r25,0,0,3 /* RPN - assuming 256 MB page size */ + add r7,r7,r4 + + stw r6,0(r3) + stw r7,4(r3) +#endif + /* * Decide what sort of machine this is and initialize the MMU. */ @@ -1001,9 +1025,6 @@ clear_utlb_entry: lis r3,PAGE_OFFSET@h ori r3,r3,PAGE_OFFSET@l - /* Kernel is at the base of RAM */ - li r4, 0 /* Load the kernel physical address */ - /* Load the kernel PID = 0 */ li r0,0 mtspr SPRN_PID,r0 @@ -1013,9 +1034,8 @@ clear_utlb_entry: clrrwi r3,r3,12 /* Mask off the effective page number */ ori r3,r3,PPC47x_TLB0_VALID | PPC47x_TLB0_256M - /* Word 1 */ - clrrwi r4,r4,12 /* Mask off the real page number */ - /* ERPN is 0 for first 4GB page */ + /* Word 1 - use r25. RPN is the same as the original entry */ + /* Word 2 */ li r5,0 ori r5,r5,PPC47x_TLB2_S_RWX @@ -1026,7 +1046,7 @@ clear_utlb_entry: /* We write to way 0 and bolted 0 */ lis r0,0x8800 tlbwe r3,r0,0 - tlbwe r4,r0,1 + tlbwe r25,r0,1 tlbwe r5,r0,2 /* @@ -1124,7 +1144,13 @@ head_start_common: lis r4,interrupt_base@h /* IVPR only uses the high 16-bits */ mtspr SPRN_IVPR,r4 - addis r22,r22,KERNELBASE@h + /* + * If the kernel was loaded at a non-zero 256 MB page, we need to + * mask off the most significant 4 bits to get the relative address + * from the start of physical memory + */ + rlwinm r22,r22,0,4,31 + addis r22,r22,PAGE_OFFSET@h mtlr r22 isync blr |