xref: /freebsd/sys/powerpc/aim/locore64.S (revision 405c3050f102b8c74782f0366c8ead927bd07b68)
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/*
69 * Entry point for bootloaders that do not fully implement ELF and start
70 * at the beginning of the image (kexec, notably). In its own section so
71 * that it ends up before any linker-generated call stubs and actually at
72 * the beginning of the image. kexec on some systems also enters at
73 * (start of image) + 0x60, so put a spin loop there.
74 */
75	.section ".text.kboot", "x", @progbits
76kbootentry:
77	b __start
78. = kbootentry + 0x40	/* Magic address used in platform layer */
79	.global smp_spin_sem
80ap_kexec_spin_sem:
81	.long   -1
82. = kbootentry + 0x60	/* Entry point for kexec APs */
83ap_kexec_start:		/* At 0x60 past start, copied to 0x60 by kexec */
84	/* r3 set to CPU ID by kexec */
85
86	/* Invalidate icache for low-memory copy and jump there */
87	li	%r0,0x80
88	dcbst	0,%r0
89	sync
90	icbi	0,%r0
91	isync
92	ba	0x80			/* Absolute branch to next inst */
93
94. = kbootentry + 0x80			/* Aligned to cache line */
951:	or	31,31,31		/* yield */
96	sync
97	lwz	%r1,0x40(0)		/* Spin on ap_kexec_spin_sem */
98	cmpw	%r1,%r3			/* Until it equals our CPU ID */
99	bne	1b
100
101	/* Released */
102	or	2,2,2			/* unyield */
103
104	/* Make sure that it will be software reset. Clear SRR1 */
105	li	%r1,0
106	mtsrr1	%r1
107	ba	EXC_RST
108
109/*
110 * Now start the real text section
111 */
112
113	.text
114	.globl	btext
115btext:
116
117/*
118 * Main kernel entry point.
119 *
120 * Calling convention:
121 * r3: Flattened Device Tree pointer (or zero)
122 * r4: ignored
123 * r5: OF client interface pointer (or zero)
124 * r6: Loader metadata pointer (or zero)
125 * r7: Magic cookie (0xfb5d104d) to indicate that r6 has loader metadata
126 */
127	.text
128ASENTRY_NOPROF(__start)
129	/* Set 64-bit mode if not yet set before branching to C */
130	mfmsr	%r20
131	li	%r21,1
132	insrdi	%r20,%r21,1,0
133	mtmsrd	%r20
134	isync
135	nop	/* Make this block a multiple of 8 bytes */
136
137	/* Set up the TOC pointer */
138	b	0f
139	.align 3
1400:	nop
141	bl	1f
142	.llong	__tocbase + 0x8000 - .
1431:	mflr	%r2
144	ld	%r1,0(%r2)
145	add	%r2,%r1,%r2
146
147	/* Get load offset */
148	ld	%r31,-0x8000(%r2) /* First TOC entry is TOC base */
149	subf    %r31,%r31,%r2	/* Subtract from real TOC base to get base */
150
151	/* Set up the stack pointer */
152	bl	1f
153	.llong	tmpstk + TMPSTKSZ - 96 - .
1541:	mflr	%r30
155	ld	%r1,0(%r30)
156	add	%r1,%r1,%r30
157	nop
158
159	/* Relocate kernel */
160	std	%r3,48(%r1)
161	std	%r4,56(%r1)
162	std	%r5,64(%r1)
163	std	%r6,72(%r1)
164	std	%r7,80(%r1)
165
166	bl	1f
167	.llong _DYNAMIC-.
1681:	mflr	%r3
169	ld	%r4,0(%r3)
170	add	%r3,%r4,%r3
171	mr	%r4,%r31
172	bl	elf_reloc_self
173	nop
174	ld	%r3,48(%r1)
175	ld	%r4,56(%r1)
176	ld	%r5,64(%r1)
177	ld	%r6,72(%r1)
178	ld	%r7,80(%r1)
179
180	/* Begin CPU init */
181	mr	%r4,%r2 /* Replace ignored r4 with tocbase for trap handlers */
182	bl	powerpc_init
183	nop
184
185	/* Set stack pointer to new value and branch to mi_startup */
186	mr	%r1, %r3
187	li	%r3, 0
188	std	%r3, 0(%r1)
189	bl	mi_startup
190	nop
191
192	/* Unreachable */
193	b	.
194
195ASENTRY_NOPROF(__restartkernel)
196	/*
197	 * r3-r7: arguments to go to __start
198	 * r8: offset from current kernel address to apply
199	 * r9: MSR to set when (atomically) jumping to __start + r8
200	 */
201	mtsrr1	%r9
202	bl	1f
2031:	mflr	%r25
204	add	%r25,%r8,%r25
205	addi	%r25,%r25,2f-1b
206	mtsrr0	%r25
207	rfid
2082:	bl	__start
209	nop
210
211#include <powerpc/aim/trap_subr64.S>
212