xref: /freebsd/sys/powerpc/aim/locore64.S (revision efe3b0de1438e7a8473d92f2be57072394559e3c)
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	.text
65	.globl	btext
66btext:
67
68/*
69 * Main kernel entry point.
70 *
71 * Calling convention:
72 * r3: Flattened Device Tree pointer (or zero)
73 * r4: ignored
74 * r5: OF client interface pointer (or zero)
75 * r6: Loader metadata pointer (or zero)
76 */
77	.text
78ASENTRY_NOPROF(__start)
79	/* Set 64-bit mode if not yet set before branching to C */
80	mfmsr	%r20
81	li	%r21,1
82	insrdi	%r20,%r21,1,0
83	mtmsrd	%r20
84	isync
85	nop	/* Make this block a multiple of 8 bytes */
86
87	/* Set up the TOC pointer */
88	b	0f
89	.align 3
900:	nop
91	bl	1f
92	.llong	__tocbase + 0x8000 - .
931:	mflr	%r2
94	ld	%r1,0(%r2)
95	add	%r2,%r1,%r2
96
97	/* Get load offset */
98	ld	%r31,-0x8000(%r2) /* First TOC entry is TOC base */
99	subf    %r31,%r31,%r2	/* Subtract from real TOC base to get base */
100
101	/* Set up the stack pointer */
102	ld	%r1,TOC_REF(tmpstk)(%r2)
103	addi	%r1,%r1,TMPSTKSZ-96
104	add	%r1,%r1,%r31
105
106	/* Relocate kernel */
107	std	%r3,48(%r1)
108	std	%r4,56(%r1)
109	std	%r5,64(%r1)
110	std	%r6,72(%r1)
111	bl	1f
112	.llong _DYNAMIC-.
1131:	mflr	%r3
114	ld	%r4,0(%r3)
115	add	%r3,%r4,%r3
116	mr	%r4,%r31
117	bl	elf_reloc_self
118	nop
119	ld	%r3,48(%r1)
120	ld	%r4,56(%r1)
121	ld	%r5,64(%r1)
122	ld	%r6,72(%r1)
123
124	/* Begin CPU init */
125	mr	%r4,%r2 /* Replace ignored r4 with tocbase for trap handlers */
126	bl	powerpc_init
127	nop
128
129	/* Set stack pointer to new value and branch to mi_startup */
130	mr	%r1, %r3
131	li	%r3, 0
132	std	%r3, 0(%r1)
133	bl	mi_startup
134	nop
135
136	/* Unreachable */
137	b	.
138
139#include <powerpc/aim/trap_subr64.S>
140