2 * Copyright (C) Paul Mackerras 1997.
4 * Adapted for 64 bit LE PowerPC by Andrew Tauferner
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
16 RELACOUNT = 0x6ffffff9
19 /* A procedure descriptor used when booting this as a COFF file.
20 * When making COFF, this comes first in the link and we're
23 .globl _zimage_start_opd
25 .long 0x500000, 0, 0, 0
31 p_start: .8byte _start
32 p_etext: .8byte _etext
33 p_bss_start: .8byte __bss_start
36 p_toc: .8byte __toc_start + 0x8000 - p_base
37 p_dyn: .8byte __dynamic_start - p_base
38 p_rela: .8byte __rela_dyn_start - p_base
40 .weak _platform_stack_top
41 p_pstack: .8byte _platform_stack_top
45 p_bss_start: .long __bss_start
48 .weak _platform_stack_top
49 p_pstack: .long _platform_stack_top
54 .globl _zimage_start_lib
56 /* Work out the offset between the address we were linked at
57 and the address where we're running. */
59 p_base: mflr r10 /* r10 now points to runtime addr of p_base */
61 /* grab the link address of the dynamic section in r11 */
62 addis r11,r10,(_GLOBAL_OFFSET_TABLE_-p_base)@ha
63 lwz r11,(_GLOBAL_OFFSET_TABLE_-p_base)@l(r11)
65 beq 3f /* if not linked -pie */
66 /* get the runtime address of the dynamic section in r12 */
68 addis r12,r10,(__dynamic_start-p_base)@ha
69 addi r12,r12,(__dynamic_start-p_base)@l
70 subf r11,r11,r12 /* runtime - linktime offset */
72 /* The dynamic section contains a series of tagged entries.
73 * We need the RELA and RELACOUNT entries. */
76 9: lwz r8,0(r12) /* get tag */
78 beq 10f /* end of list */
81 lwz r9,4(r12) /* get RELA pointer in r9 */
83 11: addis r8,r8,(-RELACOUNT)@ha
86 lwz r0,4(r12) /* get RELACOUNT value in r0 */
90 /* The relocation section contains a list of relocations.
91 * We now do the R_PPC_RELATIVE ones, which point to words
92 * which need to be initialized with addend + offset.
93 * The R_PPC_RELATIVE ones come first and there are RELACOUNT
95 10: /* skip relocation if we don't have both */
101 add r9,r9,r11 /* Relocate RELA pointer */
103 2: lbz r0,4+3(r9) /* ELF32_R_INFO(reloc->r_info) */
104 cmpwi r0,22 /* R_PPC_RELATIVE */
106 lwz r12,0(r9) /* reloc->r_offset */
107 lwz r0,8(r9) /* reloc->r_addend */
113 /* Do a cache flush for our text, in case the loader didn't */
114 3: lwz r9,p_start-p_base(r10) /* note: these are relocated now */
115 lwz r8,p_etext-p_base(r10)
125 lwz r9,p_bss_start-p_base(r10)
126 lwz r8,p_end-p_base(r10)
133 /* Possibly set up a custom stack */
134 lwz r8,p_pstack-p_base(r10)
139 stwu r0,-16(r1) /* establish a stack frame */
141 #else /* __powerpc64__ */
142 /* Save the prom pointer at p_prom. */
143 std r5,(p_prom-p_base)(r10)
145 /* Set r2 to the TOC. */
146 ld r2,(p_toc-p_base)(r10)
149 /* Grab the link address of the dynamic section in r11. */
152 beq 3f /* if not linked -pie then no dynamic section */
154 ld r11,(p_dyn-p_base)(r10)
156 ld r9,(p_rela-p_base)(r10)
161 9: ld r12,0(r11) /* get tag */
163 beq 12f /* end of list */
166 ld r13,8(r11) /* get RELA pointer in r13 */
168 10: addis r12,r12,(-RELACOUNT)@ha
169 cmpdi r12,RELACOUNT@l
171 ld r8,8(r11) /* get RELACOUNT value in r8 */
175 cmpdi r13,0 /* check we have both RELA and RELACOUNT */
180 /* Calcuate the runtime offset. */
183 /* Run through the list of relocations and process the
184 * R_PPC64_RELATIVE ones. */
186 13: ld r0,8(r9) /* ELF64_R_TYPE(reloc->r_info) */
187 cmpdi r0,22 /* R_PPC64_RELATIVE */
189 ld r12,0(r9) /* reloc->r_offset */
190 ld r0,16(r9) /* reloc->r_addend */
196 /* Do a cache flush for our text, in case the loader didn't */
197 3: ld r9,p_start-p_base(r10) /* note: these are relocated now */
198 ld r8,p_etext-p_base(r10)
208 ld r9,p_bss_start-p_base(r10)
209 ld r8,p_end-p_base(r10)
216 /* Possibly set up a custom stack */
217 ld r8,p_pstack-p_base(r10)
222 stdu r0,-112(r1) /* establish a stack frame */
224 #endif /* __powerpc64__ */
225 /* Call platform_init() */
233 #define PROM_FRAME_SIZE 512
234 #define SAVE_GPR(n, base) std n,8*(n)(base)
235 #define REST_GPR(n, base) ld n,8*(n)(base)
236 #define SAVE_2GPRS(n, base) SAVE_GPR(n, base); SAVE_GPR(n+1, base)
237 #define SAVE_4GPRS(n, base) SAVE_2GPRS(n, base); SAVE_2GPRS(n+2, base)
238 #define SAVE_8GPRS(n, base) SAVE_4GPRS(n, base); SAVE_4GPRS(n+4, base)
239 #define SAVE_10GPRS(n, base) SAVE_8GPRS(n, base); SAVE_2GPRS(n+8, base)
240 #define REST_2GPRS(n, base) REST_GPR(n, base); REST_GPR(n+1, base)
241 #define REST_4GPRS(n, base) REST_2GPRS(n, base); REST_2GPRS(n+2, base)
242 #define REST_8GPRS(n, base) REST_4GPRS(n, base); REST_4GPRS(n+4, base)
243 #define REST_10GPRS(n, base) REST_8GPRS(n, base); REST_2GPRS(n+8, base)
245 /* prom handles the jump into and return from firmware. The prom args pointer
251 stdu r1,-PROM_FRAME_SIZE(r1) /* Save SP and create stack space */
262 /* remove MSR_LE from msr but keep MSR_SF */
267 /* Load FW address, set LR to label 1, and jump to FW */
273 ld r10,(p_prom-0b)(r10)
278 1: /* Return from OF */
281 /* Restore registers and return. */
284 /* Restore the MSR (back to 64 bits) */
289 /* Restore other registers */
297 addi r1,r1,PROM_FRAME_SIZE