summaryrefslogtreecommitdiffstats
path: root/arch/arm/cpu/start-pbl.c
blob: 932a3da9e2345b809f193212bcfec6fa5a3b8f58 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
/*
 * start-pbl.c
 *
 * Copyright (c) 2010-2012 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
 * Copyright (c) 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <common.h>
#include <init.h>
#include <sizes.h>
#include <asm/barebox-arm.h>
#include <asm/barebox-arm-head.h>
#include <asm-generic/memory_layout.h>
#include <asm/sections.h>
#include <asm/pgtable.h>
#include <asm/cache.h>

#include "mmu.h"

unsigned long free_mem_ptr;
unsigned long free_mem_end_ptr;

void __naked __section(.text_head_entry) pbl_start(void)
{
	barebox_arm_head();
}

extern void *input_data;
extern void *input_data_end;

#define STATIC static

#ifdef CONFIG_IMAGE_COMPRESSION_LZO
#include "../../../lib/decompress_unlzo.c"
#endif

#ifdef CONFIG_IMAGE_COMPRESSION_GZIP
#include "../../../../lib/decompress_inflate.c"
#endif

static unsigned long *ttb;

static void create_sections(unsigned long addr, int size, unsigned int flags)
{
	int i;

	addr >>= 20;
	size >>= 20;

	for (i = size; i > 0; i--, addr++)
		ttb[addr] = (addr << 20) | flags;
}

static void map_cachable(unsigned long start, unsigned long size)
{
	start &= ~(SZ_1M - 1);
	size = (size + (SZ_1M - 1)) & ~(SZ_1M - 1);

	create_sections(start, size, PMD_SECT_AP_WRITE |
			PMD_SECT_AP_READ | PMD_TYPE_SECT | PMD_SECT_WB);
}

static void mmu_enable(unsigned long compressed_start, unsigned int len)
{
	int i;

	/* Set the ttb register */
	asm volatile ("mcr  p15,0,%0,c2,c0,0" : : "r"(ttb) /*:*/);

	/* Set the Domain Access Control Register */
	i = 0x3;
	asm volatile ("mcr  p15,0,%0,c3,c0,0" : : "r"(i) /*:*/);

	create_sections(0, 4096, PMD_SECT_AP_WRITE |
			PMD_SECT_AP_READ | PMD_TYPE_SECT);
	/*
	 * Setup all regions we need cacheable, namely:
	 * - the stack
	 * - the decompressor code
	 * - the compressed image
	 * - the uncompressed image
	 * - the early malloc space
	 */
	map_cachable(STACK_BASE, STACK_SIZE);
	map_cachable((unsigned long)&_text,
			(unsigned long)&_end - (unsigned long)&_text);
	map_cachable((unsigned long)compressed_start, len);
	map_cachable(TEXT_BASE, len * 4);
	map_cachable(free_mem_ptr, free_mem_end_ptr - free_mem_ptr);

	__mmu_cache_on();
}

static void mmu_disable(void)
{
	__mmu_cache_flush();
	__mmu_cache_off();
}

static void barebox_uncompress(void *compressed_start, unsigned int len)
{
	void (*barebox)(void);
	int use_mmu = IS_ENABLED(CONFIG_MMU);

	/* set 128 KiB at the end of the MALLOC_BASE for early malloc */
	free_mem_ptr = MALLOC_BASE + MALLOC_SIZE - SZ_128K;
	free_mem_end_ptr = free_mem_ptr + SZ_128K;

	ttb = (void *)((free_mem_ptr - 0x4000) & ~0x3fff);

	if (use_mmu)
		mmu_enable((unsigned long)compressed_start, len);

	if (IS_ENABLED(CONFIG_THUMB2_BAREBOX))
		barebox = (void *)(TEXT_BASE + 1);
	else
		barebox = (void *)TEXT_BASE;

	decompress((void *)compressed_start,
			len,
			NULL, NULL,
			(void *)TEXT_BASE, NULL, NULL);

	if (use_mmu)
		mmu_disable();

	flush_icache();

	barebox();
}

/*
 * Board code can jump here by either returning from board_init_lowlevel
 * or by calling this function directly.
 */
void __naked __section(.text_ll_return) board_init_lowlevel_return(void)
{
	uint32_t r, addr, offset;
	uint32_t pg_start, pg_end, pg_len;

	/*
	 * Get runtime address of this function. Do not
	 * put any code above this.
	 */
	__asm__ __volatile__("1: adr %0, 1b":"=r"(addr));

	/* Setup the stack */
	r = STACK_BASE + STACK_SIZE - 16;
	__asm__ __volatile__("mov sp, %0" : : "r"(r));

	/* Get offset between linked address and runtime address */
	offset = (uint32_t)__ll_return - addr;

	pg_start = (uint32_t)&input_data - offset;
	pg_end = (uint32_t)&input_data_end - offset;
	pg_len = pg_end - pg_start;

	if (IS_ENABLED(CONFIG_PBL_FORCE_PIGGYDATA_COPY))
		goto copy_piggy_link;

	/*
	 * Check if the piggydata binary will be overwritten
	 * by the uncompressed binary or by the pbl relocation
	 */
	if (!offset ||
	    !((pg_start >= TEXT_BASE && pg_start < TEXT_BASE + pg_len * 4) ||
	      ((uint32_t)_text >= pg_start && (uint32_t)_text <= pg_end)))
		goto copy_link;

copy_piggy_link:
	/*
	 * copy piggydata binary to its link address
	 */
	memcpy(&input_data, (void *)pg_start, pg_len);
	pg_start = (uint32_t)&input_data;

copy_link:
	/* relocate to link address if necessary */
	if (offset)
		memcpy((void *)_text, (void *)(_text - offset),
				__bss_start - _text);

	/* clear bss */
	memset(__bss_start, 0, __bss_stop - __bss_start);

	flush_icache();

	r = (unsigned int)&barebox_uncompress;
	/* call barebox_uncompress with its absolute address */
	__asm__ __volatile__(
		"mov r0, %1\n"
		"mov r1, %2\n"
		"mov pc, %0\n"
		:
		: "r"(r), "r"(pg_start), "r"(pg_len)
		: "r0", "r1");
}