xref: /freebsd/sys/powerpc/aim/locore64.S (revision 137a344c6341d1469432e9deb3a25593f96672ad)
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.s"
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
39#ifdef _CALL_ELF
40.abiversion _CALL_ELF
41#endif
42
43/* Glue for linker script */
44.globl  kernbase
45.set    kernbase, KERNBASE
46
47/*
48 * Globals
49 */
50	.data
51	.align 3
52GLOBAL(__startkernel)
53	.llong	begin
54GLOBAL(__endkernel)
55	.llong	end
56
57	.align	4
58#define	TMPSTKSZ	16384		/* 16K temporary stack */
59GLOBAL(tmpstk)
60	.space	TMPSTKSZ
61
62TOC_ENTRY(tmpstk)
63
64/*
65 * Entry point for bootloaders that do not fully implement ELF and start
66 * at the beginning of the image (kexec, notably). In its own section so
67 * that it ends up before any linker-generated call stubs and actually at
68 * the beginning of the image. kexec on some systems also enters at
69 * (start of image) + 0x60, so put a spin loop there.
70 */
71	.section ".text.kboot", "x", @progbits
72kbootentry:
73	b __start
74. = kbootentry + 0x40	/* Magic address used in platform layer */
75	.global smp_spin_sem
76ap_kexec_spin_sem:
77	.long   -1
78. = kbootentry + 0x60	/* Entry point for kexec APs */
79ap_kexec_start:		/* At 0x60 past start, copied to 0x60 by kexec */
80	/* r3 set to CPU ID by kexec */
81
82	/* Invalidate icache for low-memory copy and jump there */
83	li	%r0,0x80
84	dcbst	0,%r0
85	sync
86	icbi	0,%r0
87	isync
88	ba	0x80			/* Absolute branch to next inst */
89
90. = kbootentry + 0x80			/* Aligned to cache line */
911:	or	31,31,31		/* yield */
92	sync
93	lwz	%r1,0x40(0)		/* Spin on ap_kexec_spin_sem */
94	cmpw	%r1,%r3			/* Until it equals our CPU ID */
95	bne	1b
96
97	/* Released */
98	or	2,2,2			/* unyield */
99	ba	EXC_RST
100
101
102/*
103 * Now start the real text section
104 */
105
106	.text
107	.globl	btext
108btext:
109
110/*
111 * Main kernel entry point.
112 *
113 * Calling convention:
114 * r3: Flattened Device Tree pointer (or zero)
115 * r4: ignored
116 * r5: OF client interface pointer (or zero)
117 * r6: Loader metadata pointer (or zero)
118 * r7: Magic cookie (0xfb5d104d) to indicate that r6 has loader metadata
119 */
120	.text
121ASENTRY_NOPROF(__start)
122	/* Set 64-bit mode if not yet set before branching to C */
123	mfmsr	%r20
124	li	%r21,1
125	insrdi	%r20,%r21,1,0
126	mtmsrd	%r20
127	isync
128	nop	/* Make this block a multiple of 8 bytes */
129
130	/* Set up the TOC pointer */
131	b	0f
132	.align 3
1330:	nop
134	bl	1f
135	.llong	__tocbase + 0x8000 - .
1361:	mflr	%r2
137	ld	%r1,0(%r2)
138	add	%r2,%r1,%r2
139
140	/* Get load offset */
141	ld	%r31,-0x8000(%r2) /* First TOC entry is TOC base */
142	subf    %r31,%r31,%r2	/* Subtract from real TOC base to get base */
143
144	/* Set up the stack pointer */
145	ld	%r1,TOC_REF(tmpstk)(%r2)
146	addi	%r1,%r1,TMPSTKSZ-96
147	add	%r1,%r1,%r31
148
149	/* Relocate kernel */
150	std	%r3,48(%r1)
151	std	%r4,56(%r1)
152	std	%r5,64(%r1)
153	std	%r6,72(%r1)
154	std	%r7,80(%r1)
155
156	bl	1f
157	.llong _DYNAMIC-.
1581:	mflr	%r3
159	ld	%r4,0(%r3)
160	add	%r3,%r4,%r3
161	mr	%r4,%r31
162	bl	elf_reloc_self
163	nop
164	ld	%r3,48(%r1)
165	ld	%r4,56(%r1)
166	ld	%r5,64(%r1)
167	ld	%r6,72(%r1)
168	ld	%r7,80(%r1)
169
170	/* Begin CPU init */
171	mr	%r4,%r2 /* Replace ignored r4 with tocbase for trap handlers */
172	bl	powerpc_init
173	nop
174
175	/* Set stack pointer to new value and branch to mi_startup */
176	mr	%r1, %r3
177	li	%r3, 0
178	std	%r3, 0(%r1)
179	bl	mi_startup
180	nop
181
182	/* Unreachable */
183	b	.
184
185#include <powerpc/aim/trap_subr64.S>
186