| /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| /* |
| * Code to process dynamic relocations in the kernel. |
| * |
| * Copyright 2008 Paul Mackerras, IBM Corp. |
| */ |
| |
| #include <asm/ppc_asm.h> |
| |
| RELA = 7 |
| RELACOUNT = 0x6ffffff9 |
| R_PPC64_RELATIVE = 22 |
| |
| /* |
| * r3 = desired final address of kernel |
| */ |
| _GLOBAL(relocate) |
| mflr r0 |
| bcl 20,31,$+4 |
| 0: mflr r12 /* r12 has runtime addr of label 0 */ |
| mtlr r0 |
| ld r11,(p_dyn - 0b)(r12) |
| add r11,r11,r12 /* r11 has runtime addr of .dynamic section */ |
| ld r9,(p_rela - 0b)(r12) |
| add r9,r9,r12 /* r9 has runtime addr of .rela.dyn section */ |
| ld r10,(p_st - 0b)(r12) |
| add r10,r10,r12 /* r10 has runtime addr of _stext */ |
| |
| /* |
| * Scan the dynamic section for the RELA and RELACOUNT entries. |
| */ |
| li r7,0 |
| li r8,0 |
| 1: ld r6,0(r11) /* get tag */ |
| cmpdi r6,0 |
| beq 4f /* end of list */ |
| cmpdi r6,RELA |
| bne 2f |
| ld r7,8(r11) /* get RELA pointer in r7 */ |
| b 3f |
| 2: addis r6,r6,(-RELACOUNT)@ha |
| cmpdi r6,RELACOUNT@l |
| bne 3f |
| ld r8,8(r11) /* get RELACOUNT value in r8 */ |
| 3: addi r11,r11,16 |
| b 1b |
| 4: cmpdi r7,0 /* check we have both RELA and RELACOUNT */ |
| cmpdi cr1,r8,0 |
| beq 6f |
| beq cr1,6f |
| |
| /* |
| * Work out linktime address of _stext and hence the |
| * relocation offset to be applied. |
| * cur_offset [r7] = rela.run [r9] - rela.link [r7] |
| * _stext.link [r10] = _stext.run [r10] - cur_offset [r7] |
| * final_offset [r3] = _stext.final [r3] - _stext.link [r10] |
| */ |
| subf r7,r7,r9 /* cur_offset */ |
| subf r10,r7,r10 |
| subf r3,r10,r3 /* final_offset */ |
| |
| /* |
| * Run through the list of relocations and process the |
| * R_PPC64_RELATIVE ones. |
| */ |
| mtctr r8 |
| 5: ld r0,8(9) /* ELF64_R_TYPE(reloc->r_info) */ |
| cmpdi r0,R_PPC64_RELATIVE |
| bne 6f |
| ld r6,0(r9) /* reloc->r_offset */ |
| ld r0,16(r9) /* reloc->r_addend */ |
| add r0,r0,r3 |
| stdx r0,r7,r6 |
| addi r9,r9,24 |
| bdnz 5b |
| |
| 6: blr |
| |
| .balign 8 |
| p_dyn: .8byte __dynamic_start - 0b |
| p_rela: .8byte __rela_dyn_start - 0b |
| p_st: .8byte _stext - 0b |
| |
