main.c revision 430b01e8f5e524a2bfa50074d97d0bdc2505807b 
1/*
2 * Copyright (C) Paul Mackerras 1997.
3 *
4 * Updates for PPC64 by Todd Inglett, Dave Engebretsen & Peter Bergner.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11#include <stdarg.h>
12#include <stddef.h>
13#include "elf.h"
14#include "page.h"
15#include "string.h"
16#include "stdio.h"
17#include "ops.h"
18#include "gunzip_util.h"
19#include "reg.h"
20
21static struct gunzip_state gzstate;
22
23struct addr_range {
24	void *addr;
25	unsigned long size;
26};
27
28#undef DEBUG
29
30static struct addr_range prep_kernel(void)
31{
32	char elfheader[256];
33	void *vmlinuz_addr = _vmlinux_start;
34	unsigned long vmlinuz_size = _vmlinux_end - _vmlinux_start;
35	void *addr = 0;
36	struct elf_info ei;
37	int len;
38
39	/* gunzip the ELF header of the kernel */
40	gunzip_start(&gzstate, vmlinuz_addr, vmlinuz_size);
41	gunzip_exactly(&gzstate, elfheader, sizeof(elfheader));
42
43	if (!parse_elf64(elfheader, &ei) && !parse_elf32(elfheader, &ei))
44		fatal("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
45
46	if (platform_ops.image_hdr)
47		platform_ops.image_hdr(elfheader);
48
49	/* We need to alloc the memsize: gzip will expand the kernel
50	 * text/data, then possible rubbish we don't care about. But
51	 * the kernel bss must be claimed (it will be zero'd by the
52	 * kernel itself)
53	 */
54	printf("Allocating 0x%lx bytes for kernel ...\n\r", ei.memsize);
55
56	if (platform_ops.vmlinux_alloc) {
57		addr = platform_ops.vmlinux_alloc(ei.memsize);
58	} else {
59		if ((unsigned long)_start < ei.memsize)
60			fatal("Insufficient memory for kernel at address 0!"
61			       " (_start=%p)\n\r", _start);
62	}
63
64	/* Finally, gunzip the kernel */
65	printf("gunzipping (0x%p <- 0x%p:0x%p)...", addr,
66	       vmlinuz_addr, vmlinuz_addr+vmlinuz_size);
67	/* discard up to the actual load data */
68	gunzip_discard(&gzstate, ei.elfoffset - sizeof(elfheader));
69	len = gunzip_finish(&gzstate, addr, ei.loadsize);
70	if (len != ei.loadsize)
71		fatal("ran out of data!  only got 0x%x of 0x%lx bytes.\n\r",
72				len, ei.loadsize);
73	printf("done 0x%x bytes\n\r", len);
74
75	flush_cache(addr, ei.loadsize);
76
77	return (struct addr_range){addr, ei.memsize};
78}
79
80static struct addr_range prep_initrd(struct addr_range vmlinux, void *chosen,
81				     unsigned long initrd_addr,
82				     unsigned long initrd_size)
83{
84	/* If we have an image attached to us, it overrides anything
85	 * supplied by the loader. */
86	if (_initrd_end > _initrd_start) {
87		printf("Attached initrd image at 0x%p-0x%p\n\r",
88		       _initrd_start, _initrd_end);
89		initrd_addr = (unsigned long)_initrd_start;
90		initrd_size = _initrd_end - _initrd_start;
91	} else if (initrd_size > 0) {
92		printf("Using loader supplied ramdisk at 0x%lx-0x%lx\n\r",
93		       initrd_addr, initrd_addr + initrd_size);
94	}
95
96	/* If there's no initrd at all, we're done */
97	if (! initrd_size)
98		return (struct addr_range){0, 0};
99
100	/*
101	 * If the initrd is too low it will be clobbered when the
102	 * kernel relocates to its final location.  In this case,
103	 * allocate a safer place and move it.
104	 */
105	if (initrd_addr < vmlinux.size) {
106		void *old_addr = (void *)initrd_addr;
107
108		printf("Allocating 0x%lx bytes for initrd ...\n\r",
109		       initrd_size);
110		initrd_addr = (unsigned long)malloc(initrd_size);
111		if (! initrd_addr)
112			fatal("Can't allocate memory for initial "
113			       "ramdisk !\n\r");
114		printf("Relocating initrd 0x%lx <- 0x%p (0x%lx bytes)\n\r",
115		       initrd_addr, old_addr, initrd_size);
116		memmove((void *)initrd_addr, old_addr, initrd_size);
117	}
118
119	printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd_addr));
120
121	/* Tell the kernel initrd address via device tree */
122	setprop_val(chosen, "linux,initrd-start", (u32)(initrd_addr));
123	setprop_val(chosen, "linux,initrd-end", (u32)(initrd_addr+initrd_size));
124
125	return (struct addr_range){(void *)initrd_addr, initrd_size};
126}
127
128/* A buffer that may be edited by tools operating on a zImage binary so as to
129 * edit the command line passed to vmlinux (by setting /chosen/bootargs).
130 * The buffer is put in it's own section so that tools may locate it easier.
131 */
132static char cmdline[COMMAND_LINE_SIZE]
133	__attribute__((__section__("__builtin_cmdline")));
134
135static void prep_cmdline(void *chosen)
136{
137	if (cmdline[0] == '\0')
138		getprop(chosen, "bootargs", cmdline, COMMAND_LINE_SIZE-1);
139
140	printf("\n\rLinux/PowerPC load: %s", cmdline);
141	/* If possible, edit the command line */
142	if (console_ops.edit_cmdline)
143		console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE);
144	printf("\n\r");
145
146	/* Put the command line back into the devtree for the kernel */
147	setprop_str(chosen, "bootargs", cmdline);
148}
149
150struct platform_ops platform_ops;
151struct dt_ops dt_ops;
152struct console_ops console_ops;
153struct loader_info loader_info;
154
155void start(void)
156{
157	struct addr_range vmlinux, initrd;
158	kernel_entry_t kentry;
159	unsigned long ft_addr = 0;
160	void *chosen;
161
162	/* Do this first, because malloc() could clobber the loader's
163	 * command line.  Only use the loader command line if a
164	 * built-in command line wasn't set by an external tool */
165	if ((loader_info.cmdline_len > 0) && (cmdline[0] == '\0'))
166		memmove(cmdline, loader_info.cmdline,
167			min(loader_info.cmdline_len, COMMAND_LINE_SIZE-1));
168
169	if (console_ops.open && (console_ops.open() < 0))
170		exit();
171	if (platform_ops.fixups)
172		platform_ops.fixups();
173
174	printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
175	       _start, get_sp());
176
177	/* Ensure that the device tree has a /chosen node */
178	chosen = finddevice("/chosen");
179	if (!chosen)
180		chosen = create_node(NULL, "chosen");
181
182	vmlinux = prep_kernel();
183	initrd = prep_initrd(vmlinux, chosen,
184			     loader_info.initrd_addr, loader_info.initrd_size);
185	prep_cmdline(chosen);
186
187	printf("Finalizing device tree...");
188	if (dt_ops.finalize)
189		ft_addr = dt_ops.finalize();
190	if (ft_addr)
191		printf(" flat tree at 0x%lx\n\r", ft_addr);
192	else
193		printf(" using OF tree (promptr=%p)\n\r", loader_info.promptr);
194
195	if (console_ops.close)
196		console_ops.close();
197
198	kentry = (kernel_entry_t) vmlinux.addr;
199	if (ft_addr)
200		kentry(ft_addr, 0, NULL);
201	else
202		kentry((unsigned long)initrd.addr, initrd.size,
203		       loader_info.promptr);
204
205	/* console closed so printf in fatal below may not work */
206	fatal("Error: Linux kernel returned to zImage boot wrapper!\n\r");
207}
208