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| /* 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
|
|
