powerpc/boot: Modify entry point for 64bit

This patch adds support a 64bit wrapper entry point. As in 32bit, the entry point does its own relocation and can be loaded at any address by the firmware. Signed-off-by: Cédric Le Goater <clg@fr.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
author: Cédric Le Goater <clg@fr.ibm.com> 2014-04-24 03:23:37 -0400
committer: Benjamin Herrenschmidt <benh@kernel.crashing.org> 2014-04-28 03:36:12 -0400
commit: f16e9684996188c12e1f460589003e99086ce36e (patch)
tree: 2072c5c57b07305fd06d2723ee41c2a4b46fea20 /arch/powerpc/boot
parent: 93d3921042988317e94b1bcc2e19844efe0b7356 (diff)
1 files changed, 104 insertions, 4 deletions
diff --git a/arch/powerpc/boot/crt0.S b/arch/powerpc/boot/crt0.S
index dbd99d064828..689290561e69 100644
--- a/arch/powerpc/boot/crt0.S
+++ b/arch/powerpc/boot/crt0.S
@@ -1,17 +1,20 @@
 /*
 * Copyright (C) Paul Mackerras 1997.
 *
+ * Adapted for 64 bit LE PowerPC by Andrew Tauferner
+ *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
- * NOTE: this code runs in 32 bit mode, is position-independent,
- * and is packaged as ELF32.
 */
 #include "ppc_asm.h"
+RELA = 7
+RELACOUNT = 0x6ffffff9
        .text
        /* A procedure descriptor used when booting this as a COFF file.
         * When making COFF, this comes first in the link and we're
@@ -21,6 +24,20 @@
 _zimage_start_opd:
        .long   0x500000, 0, 0, 0
+#ifdef __powerpc64__
+.balign 8
+p_start:        .llong  _start
+p_etext:        .llong  _etext
+p_bss_start:    .llong  __bss_start
+p_end:          .llong  _end
+p_toc:          .llong  __toc_start + 0x8000 - p_base
+p_dyn:          .llong  __dynamic_start - p_base
+p_rela:         .llong  __rela_dyn_start - p_base
+p_prom:         .llong  0
+        .weak   _platform_stack_top
+p_pstack:       .llong  _platform_stack_top
+#else
 p_start:        .long   _start
 p_etext:        .long   _etext
 p_bss_start:    .long   __bss_start
@@ -28,6 +45,7 @@ p_end:		.long	_end
        .weak   _platform_stack_top
 p_pstack:       .long   _platform_stack_top
+#endif
        .weak   _zimage_start
        .globl  _zimage_start
@@ -38,6 +56,7 @@ _zimage_start_lib:
           and the address where we're running. */
        bl      .+4
 p_base: mflr    r10             /* r10 now points to runtime addr of p_base */
+#ifndef __powerpc64__
        /* grab the link address of the dynamic section in r11 */
        addis   r11,r10,(_GLOBAL_OFFSET_TABLE_-p_base)@ha
        lwz     r11,(_GLOBAL_OFFSET_TABLE_-p_base)@l(r11)
@@ -51,8 +70,6 @@ p_base:	mflr	r10		/* r10 now points to runtime addr of p_base */
        /* The dynamic section contains a series of tagged entries.
         * We need the RELA and RELACOUNT entries. */
-RELA = 7
-RELACOUNT = 0x6ffffff9
        li      r9,0
        li      r0,0
 9:      lwz     r8,0(r12)       /* get tag */
@@ -120,7 +137,90 @@ RELACOUNT = 0x6ffffff9
        li      r0,0
        stwu    r0,-16(r1)      /* establish a stack frame */
 6:
+#else /* __powerpc64__ */
+        /* Save the prom pointer at p_prom. */
+        std     r5,(p_prom-p_base)(r10)
+        /* Set r2 to the TOC. */
+        ld      r2,(p_toc-p_base)(r10)
+        add     r2,r2,r10
+        /* Grab the link address of the dynamic section in r11. */
+        ld      r11,-32768(r2)
+        cmpwi   r11,0
+        beq     3f              /* if not linked -pie then no dynamic section */
+        ld      r11,(p_dyn-p_base)(r10)
+        add     r11,r11,r10
+        ld      r9,(p_rela-p_base)(r10)
+        add     r9,r9,r10
+        li      r7,0
+        li      r8,0
+9:      ld      r6,0(r11)       /* get tag */
+        cmpdi   r6,0
+        beq     12f              /* end of list */
+        cmpdi   r6,RELA
+        bne     10f
+        ld      r7,8(r11)       /* get RELA pointer in r7 */
+        b       11f
+10:     addis   r6,r6,(-RELACOUNT)@ha
+        cmpdi   r6,RELACOUNT@l
+        bne     11f
+        ld      r8,8(r11)       /* get RELACOUNT value in r8 */
+11:     addi    r11,r11,16
+        b       9b
+12:
+        cmpdi   r7,0            /* check we have both RELA and RELACOUNT */
+        cmpdi   cr1,r8,0
+        beq     3f
+        beq     cr1,3f
+        /* Calcuate the runtime offset. */
+        subf    r7,r7,r9
+        /* Run through the list of relocations and process the
+         * R_PPC64_RELATIVE ones. */
+        mtctr   r8
+13:     ld      r0,8(r9)        /* ELF64_R_TYPE(reloc->r_info) */
+        cmpdi   r0,22           /* R_PPC64_RELATIVE */
+        bne     3f
+        ld      r6,0(r9)        /* reloc->r_offset */
+        ld      r0,16(r9)       /* reloc->r_addend */
+        add     r0,r0,r7
+        stdx    r0,r7,r6
+        addi    r9,r9,24
+        bdnz    13b
+        /* Do a cache flush for our text, in case the loader didn't */
+3:      ld      r9,p_start-p_base(r10)  /* note: these are relocated now */
+        ld      r8,p_etext-p_base(r10)
+4:      dcbf    r0,r9
+        icbi    r0,r9
+        addi    r9,r9,0x20
+        cmpld   cr0,r9,r8
+        blt     4b
+        sync
+        isync
+        /* Clear the BSS */
+        ld      r9,p_bss_start-p_base(r10)
+        ld      r8,p_end-p_base(r10)
+        li      r0,0
+5:      std     r0,0(r9)
+        addi    r9,r9,8
+        cmpld   cr0,r9,r8
+        blt     5b
+        /* Possibly set up a custom stack */
+        ld      r8,p_pstack-p_base(r10)
+        cmpdi   r8,0
+        beq     6f
+        ld      r1,0(r8)
+        li      r0,0
+        stdu    r0,-16(r1)      /* establish a stack frame */
+6:
+#endif  /* __powerpc64__ */
        /* Call platform_init() */
        bl      platform_init
author	Cédric Le Goater <clg@fr.ibm.com>	2014-04-24 03:23:37 -0400
committer	Benjamin Herrenschmidt <benh@kernel.crashing.org>	2014-04-28 03:36:12 -0400
commit	f16e9684996188c12e1f460589003e99086ce36e (patch)
tree	2072c5c57b07305fd06d2723ee41c2a4b46fea20 /arch/powerpc/boot
parent	93d3921042988317e94b1bcc2e19844efe0b7356 (diff)

diff --git a/arch/powerpc/boot/crt0.S b/arch/powerpc/boot/crt0.S index dbd99d064828..689290561e69 100644 --- a/arch/powerpc/boot/crt0.S +++ b/arch/powerpc/boot/crt0.S
@@ -1,17 +1,20 @@
1	/*	1	/*
2	* Copyright (C) Paul Mackerras 1997.	2	* Copyright (C) Paul Mackerras 1997.
3	*	3	*
		4	* Adapted for 64 bit LE PowerPC by Andrew Tauferner
		5	*
4	* This program is free software; you can redistribute it and/or	6	* This program is free software; you can redistribute it and/or
5	* modify it under the terms of the GNU General Public License	7	* modify it under the terms of the GNU General Public License
6	* as published by the Free Software Foundation; either version	8	* as published by the Free Software Foundation; either version
7	* 2 of the License, or (at your option) any later version.	9	* 2 of the License, or (at your option) any later version.
8	*	10	*
9	* NOTE: this code runs in 32 bit mode, is position-independent,
10	* and is packaged as ELF32.
11	*/	11	*/
12		12
13	#include "ppc_asm.h"	13	#include "ppc_asm.h"
14		14
		15	RELA = 7
		16	RELACOUNT = 0x6ffffff9
		17
15	.text	18	.text
16	/* A procedure descriptor used when booting this as a COFF file.	19	/* A procedure descriptor used when booting this as a COFF file.
17	* When making COFF, this comes first in the link and we're	20	* When making COFF, this comes first in the link and we're
@@ -21,6 +24,20 @@
21	_zimage_start_opd:	24	_zimage_start_opd:
22	.long 0x500000, 0, 0, 0	25	.long 0x500000, 0, 0, 0
23		26
		27	#ifdef __powerpc64__
		28	.balign 8
		29	p_start: .llong _start
		30	p_etext: .llong _etext
		31	p_bss_start: .llong __bss_start
		32	p_end: .llong _end
		33
		34	p_toc: .llong __toc_start + 0x8000 - p_base
		35	p_dyn: .llong __dynamic_start - p_base
		36	p_rela: .llong __rela_dyn_start - p_base
		37	p_prom: .llong 0
		38	.weak _platform_stack_top
		39	p_pstack: .llong _platform_stack_top
		40	#else
24	p_start: .long _start	41	p_start: .long _start
25	p_etext: .long _etext	42	p_etext: .long _etext
26	p_bss_start: .long __bss_start	43	p_bss_start: .long __bss_start
@@ -28,6 +45,7 @@ p_end: .long _end
28		45
29	.weak _platform_stack_top	46	.weak _platform_stack_top
30	p_pstack: .long _platform_stack_top	47	p_pstack: .long _platform_stack_top
		48	#endif
31		49
32	.weak _zimage_start	50	.weak _zimage_start
33	.globl _zimage_start	51	.globl _zimage_start
@@ -38,6 +56,7 @@ _zimage_start_lib:
38	and the address where we're running. */	56	and the address where we're running. */
39	bl .+4	57	bl .+4
40	p_base: mflr r10 /* r10 now points to runtime addr of p_base */	58	p_base: mflr r10 /* r10 now points to runtime addr of p_base */
		59	#ifndef __powerpc64__
41	/* grab the link address of the dynamic section in r11 */	60	/* grab the link address of the dynamic section in r11 */
42	addis r11,r10,(_GLOBAL_OFFSET_TABLE_-p_base)@ha	61	addis r11,r10,(_GLOBAL_OFFSET_TABLE_-p_base)@ha
43	lwz r11,(_GLOBAL_OFFSET_TABLE_-p_base)@l(r11)	62	lwz r11,(_GLOBAL_OFFSET_TABLE_-p_base)@l(r11)
@@ -51,8 +70,6 @@ p_base: mflr r10 /* r10 now points to runtime addr of p_base */
51		70
52	/* The dynamic section contains a series of tagged entries.	71	/* The dynamic section contains a series of tagged entries.
53	* We need the RELA and RELACOUNT entries. */	72	* We need the RELA and RELACOUNT entries. */
54	RELA = 7
55	RELACOUNT = 0x6ffffff9
56	li r9,0	73	li r9,0
57	li r0,0	74	li r0,0
58	9: lwz r8,0(r12) /* get tag */	75	9: lwz r8,0(r12) /* get tag */
@@ -120,7 +137,90 @@ RELACOUNT = 0x6ffffff9
120	li r0,0	137	li r0,0
121	stwu r0,-16(r1) /* establish a stack frame */	138	stwu r0,-16(r1) /* establish a stack frame */
122	6:	139	6:
		140	#else /* __powerpc64__ */
		141	/* Save the prom pointer at p_prom. */
		142	std r5,(p_prom-p_base)(r10)
		143
		144	/* Set r2 to the TOC. */
		145	ld r2,(p_toc-p_base)(r10)
		146	add r2,r2,r10
		147
		148	/* Grab the link address of the dynamic section in r11. */
		149	ld r11,-32768(r2)
		150	cmpwi r11,0
		151	beq 3f /* if not linked -pie then no dynamic section */
		152
		153	ld r11,(p_dyn-p_base)(r10)
		154	add r11,r11,r10
		155	ld r9,(p_rela-p_base)(r10)
		156	add r9,r9,r10
		157
		158	li r7,0
		159	li r8,0
		160	9: ld r6,0(r11) /* get tag */
		161	cmpdi r6,0
		162	beq 12f /* end of list */
		163	cmpdi r6,RELA
		164	bne 10f
		165	ld r7,8(r11) /* get RELA pointer in r7 */
		166	b 11f
		167	10: addis r6,r6,(-RELACOUNT)@ha
		168	cmpdi r6,RELACOUNT@l
		169	bne 11f
		170	ld r8,8(r11) /* get RELACOUNT value in r8 */
		171	11: addi r11,r11,16
		172	b 9b
		173	12:
		174	cmpdi r7,0 /* check we have both RELA and RELACOUNT */
		175	cmpdi cr1,r8,0
		176	beq 3f
		177	beq cr1,3f
		178
		179	/* Calcuate the runtime offset. */
		180	subf r7,r7,r9
123		181
		182	/* Run through the list of relocations and process the
		183	* R_PPC64_RELATIVE ones. */
		184	mtctr r8
		185	13: ld r0,8(r9) /* ELF64_R_TYPE(reloc->r_info) */
		186	cmpdi r0,22 /* R_PPC64_RELATIVE */
		187	bne 3f
		188	ld r6,0(r9) /* reloc->r_offset */
		189	ld r0,16(r9) /* reloc->r_addend */
		190	add r0,r0,r7
		191	stdx r0,r7,r6
		192	addi r9,r9,24
		193	bdnz 13b
		194
		195	/* Do a cache flush for our text, in case the loader didn't */
		196	3: ld r9,p_start-p_base(r10) /* note: these are relocated now */
		197	ld r8,p_etext-p_base(r10)
		198	4: dcbf r0,r9
		199	icbi r0,r9
		200	addi r9,r9,0x20
		201	cmpld cr0,r9,r8
		202	blt 4b
		203	sync
		204	isync
		205
		206	/* Clear the BSS */
		207	ld r9,p_bss_start-p_base(r10)
		208	ld r8,p_end-p_base(r10)
		209	li r0,0
		210	5: std r0,0(r9)
		211	addi r9,r9,8
		212	cmpld cr0,r9,r8
		213	blt 5b
		214
		215	/* Possibly set up a custom stack */
		216	ld r8,p_pstack-p_base(r10)
		217	cmpdi r8,0
		218	beq 6f
		219	ld r1,0(r8)
		220	li r0,0
		221	stdu r0,-16(r1) /* establish a stack frame */
		222	6:
		223	#endif /* __powerpc64__ */
124	/* Call platform_init() */	224	/* Call platform_init() */
125	bl platform_init	225	bl platform_init
126		226