xref: /freebsd/sys/powerpc/aim/locore64.S (revision 6829dae12bb055451fa467da4589c43bd03b1e64)
1/* $FreeBSD$ */
2
3/*-
4 * Copyright (C) 2010-2016 Nathan Whitehorn
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * $FreeBSD$
28 */
29
30#include "assym.inc"
31
32#include <sys/syscall.h>
33
34#include <machine/trap.h>
35#include <machine/param.h>
36#include <machine/spr.h>
37#include <machine/asm.h>
38#include <machine/vmparam.h>
39
40#ifdef _CALL_ELF
41.abiversion _CALL_ELF
42#endif
43
44/* Glue for linker script */
45.globl  kernbase
46.set    kernbase, KERNBASE
47
48/*
49 * Globals
50 */
51	.data
52	.align 3
53GLOBAL(__startkernel)
54	.llong	begin
55GLOBAL(__endkernel)
56	.llong	end
57GLOBAL(can_wakeup)
58	.llong	0x0
59
60	.align	4
61#define	TMPSTKSZ	16384		/* 16K temporary stack */
62GLOBAL(tmpstk)
63	.space	TMPSTKSZ
64
65TOC_ENTRY(tmpstk)
66TOC_ENTRY(can_wakeup)
67
68#ifdef KDB
69#define TRAPSTKSZ       4096            /* 4k trap stack */
70GLOBAL(trapstk)
71        .space        TRAPSTKSZ
72TOC_ENTRY(trapstk)
73#endif
74
75
76/*
77 * Entry point for bootloaders that do not fully implement ELF and start
78 * at the beginning of the image (kexec, notably). In its own section so
79 * that it ends up before any linker-generated call stubs and actually at
80 * the beginning of the image. kexec on some systems also enters at
81 * (start of image) + 0x60, so put a spin loop there.
82 */
83	.section ".text.kboot", "x", @progbits
84kbootentry:
85	b __start
86. = kbootentry + 0x40	/* Magic address used in platform layer */
87	.global smp_spin_sem
88ap_kexec_spin_sem:
89	.long   -1
90. = kbootentry + 0x60	/* Entry point for kexec APs */
91ap_kexec_start:		/* At 0x60 past start, copied to 0x60 by kexec */
92	/* r3 set to CPU ID by kexec */
93
94	/* Invalidate icache for low-memory copy and jump there */
95	li	%r0,0x80
96	dcbst	0,%r0
97	sync
98	icbi	0,%r0
99	isync
100	ba	0x80			/* Absolute branch to next inst */
101
102. = kbootentry + 0x80			/* Aligned to cache line */
1031:	or	31,31,31		/* yield */
104	sync
105	lwz	%r1,0x40(0)		/* Spin on ap_kexec_spin_sem */
106	cmpw	%r1,%r3			/* Until it equals our CPU ID */
107	bne	1b
108
109	/* Released */
110	or	2,2,2			/* unyield */
111
112	/* Make sure that it will be software reset. Clear SRR1 */
113	li	%r1,0
114	mtsrr1	%r1
115	ba	EXC_RST
116
117/*
118 * Now start the real text section
119 */
120
121	.text
122	.globl	btext
123btext:
124
125/*
126 * Main kernel entry point.
127 *
128 * Calling convention:
129 * r3: Flattened Device Tree pointer (or zero)
130 * r4: ignored
131 * r5: OF client interface pointer (or zero)
132 * r6: Loader metadata pointer (or zero)
133 * r7: Magic cookie (0xfb5d104d) to indicate that r6 has loader metadata
134 */
135	.text
136ASENTRY_NOPROF(__start)
137	/* Set 64-bit mode if not yet set before branching to C */
138	mfmsr	%r20
139	li	%r21,1
140	insrdi	%r20,%r21,1,0
141	mtmsrd	%r20
142	isync
143	nop	/* Make this block a multiple of 8 bytes */
144
145	/* Set up the TOC pointer */
146	b	0f
147	.align 3
1480:	nop
149	bl	1f
150	.llong	__tocbase + 0x8000 - .
1511:	mflr	%r2
152	ld	%r1,0(%r2)
153	add	%r2,%r1,%r2
154
155	/* Get load offset */
156	ld	%r31,-0x8000(%r2) /* First TOC entry is TOC base */
157	subf    %r31,%r31,%r2	/* Subtract from real TOC base to get base */
158
159	/* Set up the stack pointer */
160	bl	1f
161	.llong	tmpstk + TMPSTKSZ - 96 - .
1621:	mflr	%r30
163	ld	%r1,0(%r30)
164	add	%r1,%r1,%r30
165	nop
166
167	/* Relocate kernel */
168	std	%r3,48(%r1)
169	std	%r4,56(%r1)
170	std	%r5,64(%r1)
171	std	%r6,72(%r1)
172	std	%r7,80(%r1)
173
174	bl	1f
175	.llong _DYNAMIC-.
1761:	mflr	%r3
177	ld	%r4,0(%r3)
178	add	%r3,%r4,%r3
179	mr	%r4,%r31
180	bl	elf_reloc_self
181	nop
182	ld	%r3,48(%r1)
183	ld	%r4,56(%r1)
184	ld	%r5,64(%r1)
185	ld	%r6,72(%r1)
186	ld	%r7,80(%r1)
187
188	/* Begin CPU init */
189	mr	%r4,%r2 /* Replace ignored r4 with tocbase for trap handlers */
190	bl	powerpc_init
191	nop
192
193	/* Set stack pointer to new value and branch to mi_startup */
194	mr	%r1, %r3
195	li	%r3, 0
196	std	%r3, 0(%r1)
197	bl	mi_startup
198	nop
199
200	/* Unreachable */
201	b	.
202
203ASENTRY_NOPROF(__restartkernel)
204	/*
205	 * r3-r7: arguments to go to __start
206	 * r8: offset from current kernel address to apply
207	 * r9: MSR to set when (atomically) jumping to __start + r8
208	 */
209	mtsrr1	%r9
210	bl	1f
2111:	mflr	%r25
212	add	%r25,%r8,%r25
213	addi	%r25,%r25,2f-1b
214	mtsrr0	%r25
215	rfid
2162:	bl	__start
217	nop
218
219#include <powerpc/aim/trap_subr64.S>
220