xref: /freebsd/sys/powerpc/aim/locore64.S (revision d06955f9bdb1416d9196043ed781f9b36dae9adc)
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 * r7: Magic cookie (0xfb5d104d) to indicate that r6 has loader metadata
77 */
78	.text
79ASENTRY_NOPROF(__start)
80	/* Set 64-bit mode if not yet set before branching to C */
81	mfmsr	%r20
82	li	%r21,1
83	insrdi	%r20,%r21,1,0
84	mtmsrd	%r20
85	isync
86	nop	/* Make this block a multiple of 8 bytes */
87
88	/* Set up the TOC pointer */
89	b	0f
90	.align 3
910:	nop
92	bl	1f
93	.llong	__tocbase + 0x8000 - .
941:	mflr	%r2
95	ld	%r1,0(%r2)
96	add	%r2,%r1,%r2
97
98	/* Get load offset */
99	ld	%r31,-0x8000(%r2) /* First TOC entry is TOC base */
100	subf    %r31,%r31,%r2	/* Subtract from real TOC base to get base */
101
102	/* Set up the stack pointer */
103	ld	%r1,TOC_REF(tmpstk)(%r2)
104	addi	%r1,%r1,TMPSTKSZ-96
105	add	%r1,%r1,%r31
106
107	/* Relocate kernel */
108	std	%r3,48(%r1)
109	std	%r4,56(%r1)
110	std	%r5,64(%r1)
111	std	%r6,72(%r1)
112	std	%r7,80(%r1)
113
114	bl	1f
115	.llong _DYNAMIC-.
1161:	mflr	%r3
117	ld	%r4,0(%r3)
118	add	%r3,%r4,%r3
119	mr	%r4,%r31
120	bl	elf_reloc_self
121	nop
122	ld	%r3,48(%r1)
123	ld	%r4,56(%r1)
124	ld	%r5,64(%r1)
125	ld	%r6,72(%r1)
126	ld	%r7,80(%r1)
127
128	/* Begin CPU init */
129	mr	%r4,%r2 /* Replace ignored r4 with tocbase for trap handlers */
130	bl	powerpc_init
131	nop
132
133	/* Set stack pointer to new value and branch to mi_startup */
134	mr	%r1, %r3
135	li	%r3, 0
136	std	%r3, 0(%r1)
137	bl	mi_startup
138	nop
139
140	/* Unreachable */
141	b	.
142
143#include <powerpc/aim/trap_subr64.S>
144