summaryrefslogtreecommitdiff
path: root/lib_m68k/bootm.c
blob: ac04da08a5c1d3494b0d2041749cbf4eff6da7f9 (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
/*
 * (C) Copyright 2003
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * 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 as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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 <command.h>
#include <image.h>
#include <zlib.h>
#include <bzlib.h>
#include <watchdog.h>
#include <environment.h>
#include <asm/byteorder.h>
#ifdef CONFIG_SHOW_BOOT_PROGRESS
# include <status_led.h>
#endif

DECLARE_GLOBAL_DATA_PTR;

#define PHYSADDR(x) x

#define LINUX_MAX_ENVS		256
#define LINUX_MAX_ARGS		256

static ulong get_sp (void);
static void set_clocks_in_mhz (bd_t *kbd);

void do_bootm_linux(cmd_tbl_t * cmdtp, int flag,
		    int argc, char *argv[],
		    image_header_t *hdr, int verify)
{
	ulong sp, sp_limit, alloc_current;

	ulong rd_data_start, rd_data_end, rd_len;
	ulong initrd_start, initrd_end;

	ulong cmd_start, cmd_end;
	bd_t *kbd;
	void (*kernel) (bd_t *, ulong, ulong, ulong, ulong);

	/*
	 * Booting a (Linux) kernel image
	 *
	 * Allocate space for command line and board info - the
	 * address should be as high as possible within the reach of
	 * the kernel (see CFG_BOOTMAPSZ settings), but in unused
	 * memory, which means far enough below the current stack
	 * pointer.
	 */
	sp = get_sp();
	debug ("## Current stack ends at 0x%08lx ", sp);

	alloc_current = sp_limit = get_boot_sp_limit(sp);
	debug ("=> set upper limit to 0x%08lx\n", sp_limit);

	/* allocate space and init command line */
	alloc_current = get_boot_cmdline (alloc_current, &cmd_start, &cmd_end);

	/* allocate space for kernel copy of board info */
	alloc_current = get_boot_kbd (alloc_current, &kbd);
	set_clocks_in_mhz(kbd);

	/* find kernel */
	kernel =
	    (void (*)(bd_t *, ulong, ulong, ulong, ulong))image_get_ep (hdr);

	/* find ramdisk */
	get_ramdisk (cmdtp, flag, argc, argv, hdr, verify,
			IH_ARCH_M68K, &rd_data_start, &rd_data_end);

	rd_len = rd_data_end - rd_data_start;
	alloc_current = ramdisk_high (alloc_current, rd_data_start, rd_len,
			kbd, sp_limit, get_sp (),
			&initrd_start, &initrd_end);

	debug("## Transferring control to Linux (at address %08lx) ...\n",
	      (ulong) kernel);

	show_boot_progress (15);

	/*
	 * Linux Kernel Parameters (passing board info data):
	 *   r3: ptr to board info data
	 *   r4: initrd_start or 0 if no initrd
	 *   r5: initrd_end - unused if r4 is 0
	 *   r6: Start of command line string
	 *   r7: End   of command line string
	 */
	(*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end);
	/* does not return */
}

static ulong get_sp (void)
{
	ulong sp;

	asm("movel %%a7, %%d0\n"
	    "movel %%d0, %0\n": "=d"(sp): :"%d0");

	return sp;
}

static void set_clocks_in_mhz (bd_t *kbd)
{
	char *s;

	if ((s = getenv("clocks_in_mhz")) != NULL) {
		/* convert all clock information to MHz */
		kbd->bi_intfreq /= 1000000L;
		kbd->bi_busfreq /= 1000000L;
	}
}