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