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 "flatdevtree.h"
20#include "reg.h"
21
22extern char _start[];
23extern char __bss_start[];
24extern char _end[];
25extern char _vmlinux_start[];
26extern char _vmlinux_end[];
27extern char _initrd_start[];
28extern char _initrd_end[];
29extern char _dtb_start[];
30extern char _dtb_end[];
31
32static struct gunzip_state gzstate;
33
34struct addr_range {
35	void *addr;
36	unsigned long size;
37};
38
39typedef void (*kernel_entry_t)(unsigned long, unsigned long, void *);
40
41#undef DEBUG
42
43static struct addr_range prep_kernel(void)
44{
45	char elfheader[256];
46	void *vmlinuz_addr = _vmlinux_start;
47	unsigned long vmlinuz_size = _vmlinux_end - _vmlinux_start;
48	void *addr = 0;
49	struct elf_info ei;
50	int len;
51
52	/* gunzip the ELF header of the kernel */
53	gunzip_start(&gzstate, vmlinuz_addr, vmlinuz_size);
54	gunzip_exactly(&gzstate, elfheader, sizeof(elfheader));
55
56	if (!parse_elf64(elfheader, &ei) && !parse_elf32(elfheader, &ei))
57		fatal("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
58
59	if (platform_ops.image_hdr)
60		platform_ops.image_hdr(elfheader);
61
62	/* We need to alloc the memsize: gzip will expand the kernel
63	 * text/data, then possible rubbish we don't care about. But
64	 * the kernel bss must be claimed (it will be zero'd by the
65	 * kernel itself)
66	 */
67	printf("Allocating 0x%lx bytes for kernel ...\n\r", ei.memsize);
68
69	if (platform_ops.vmlinux_alloc) {
70		addr = platform_ops.vmlinux_alloc(ei.memsize);
71	} else {
72		if ((unsigned long)_start < ei.memsize)
73			fatal("Insufficient memory for kernel at address 0!"
74			       " (_start=%p)\n\r", _start);
75	}
76
77	/* Finally, gunzip the kernel */
78	printf("gunzipping (0x%p <- 0x%p:0x%p)...", addr,
79	       vmlinuz_addr, vmlinuz_addr+vmlinuz_size);
80	/* discard up to the actual load data */
81	gunzip_discard(&gzstate, ei.elfoffset - sizeof(elfheader));
82	len = gunzip_finish(&gzstate, addr, ei.loadsize);
83	if (len != ei.loadsize)
84		fatal("ran out of data!  only got 0x%x of 0x%lx bytes.\n\r",
85				len, ei.loadsize);
86	printf("done 0x%x bytes\n\r", len);
87
88	flush_cache(addr, ei.loadsize);
89
90	return (struct addr_range){addr, ei.memsize};
91}
92
93static struct addr_range prep_initrd(struct addr_range vmlinux, void *chosen,
94				     unsigned long initrd_addr,
95				     unsigned long initrd_size)
96{
97	/* If we have an image attached to us, it overrides anything
98	 * supplied by the loader. */
99	if (_initrd_end > _initrd_start) {
100		printf("Attached initrd image at 0x%p-0x%p\n\r",
101		       _initrd_start, _initrd_end);
102		initrd_addr = (unsigned long)_initrd_start;
103		initrd_size = _initrd_end - _initrd_start;
104	} else if (initrd_size > 0) {
105		printf("Using loader supplied ramdisk at 0x%lx-0x%lx\n\r",
106		       initrd_addr, initrd_addr + initrd_size);
107	}
108
109	/* If there's no initrd at all, we're done */
110	if (! initrd_size)
111		return (struct addr_range){0, 0};
112
113	/*
114	 * If the initrd is too low it will be clobbered when the
115	 * kernel relocates to its final location.  In this case,
116	 * allocate a safer place and move it.
117	 */
118	if (initrd_addr < vmlinux.size) {
119		void *old_addr = (void *)initrd_addr;
120
121		printf("Allocating 0x%lx bytes for initrd ...\n\r",
122		       initrd_size);
123		initrd_addr = (unsigned long)malloc(initrd_size);
124		if (! initrd_addr)
125			fatal("Can't allocate memory for initial "
126			       "ramdisk !\n\r");
127		printf("Relocating initrd 0x%lx <- 0x%p (0x%lx bytes)\n\r",
128		       initrd_addr, old_addr, initrd_size);
129		memmove((void *)initrd_addr, old_addr, initrd_size);
130	}
131
132	printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd_addr));
133
134	/* Tell the kernel initrd address via device tree */
135	setprop_val(chosen, "linux,initrd-start", (u32)(initrd_addr));
136	setprop_val(chosen, "linux,initrd-end", (u32)(initrd_addr+initrd_size));
137
138	return (struct addr_range){(void *)initrd_addr, initrd_size};
139}
140
141/* A buffer that may be edited by tools operating on a zImage binary so as to
142 * edit the command line passed to vmlinux (by setting /chosen/bootargs).
143 * The buffer is put in it's own section so that tools may locate it easier.
144 */
145static char cmdline[COMMAND_LINE_SIZE]
146	__attribute__((__section__("__builtin_cmdline")));
147
148static void prep_cmdline(void *chosen)
149{
150	if (cmdline[0] == '\0')
151		getprop(chosen, "bootargs", cmdline, COMMAND_LINE_SIZE-1);
152
153	printf("\n\rLinux/PowerPC load: %s", cmdline);
154	/* If possible, edit the command line */
155	if (console_ops.edit_cmdline)
156		console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE);
157	printf("\n\r");
158
159	/* Put the command line back into the devtree for the kernel */
160	setprop_str(chosen, "bootargs", cmdline);
161}
162
163struct platform_ops platform_ops;
164struct dt_ops dt_ops;
165struct console_ops console_ops;
166struct loader_info loader_info;
167
168void start(void)
169{
170	struct addr_range vmlinux, initrd;
171	kernel_entry_t kentry;
172	unsigned long ft_addr = 0;
173	void *chosen;
174
175	/* Do this first, because malloc() could clobber the loader's
176	 * command line.  Only use the loader command line if a
177	 * built-in command line wasn't set by an external tool */
178	if ((loader_info.cmdline_len > 0) && (cmdline[0] == '\0'))
179		memmove(cmdline, loader_info.cmdline,
180			min(loader_info.cmdline_len, COMMAND_LINE_SIZE-1));
181
182	if (console_ops.open && (console_ops.open() < 0))
183		exit();
184	if (platform_ops.fixups)
185		platform_ops.fixups();
186
187	printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
188	       _start, get_sp());
189
190	/* Ensure that the device tree has a /chosen node */
191	chosen = finddevice("/chosen");
192	if (!chosen)
193		chosen = create_node(NULL, "chosen");
194
195	vmlinux = prep_kernel();
196	initrd = prep_initrd(vmlinux, chosen,
197			     loader_info.initrd_addr, loader_info.initrd_size);
198	prep_cmdline(chosen);
199
200	printf("Finalizing device tree...");
201	if (dt_ops.finalize)
202		ft_addr = dt_ops.finalize();
203	if (ft_addr)
204		printf(" flat tree at 0x%lx\n\r", ft_addr);
205	else
206		printf(" using OF tree (promptr=%p)\n\r", loader_info.promptr);
207
208	if (console_ops.close)
209		console_ops.close();
210
211	kentry = (kernel_entry_t) vmlinux.addr;
212	if (ft_addr)
213		kentry(ft_addr, 0, NULL);
214	else
215		kentry((unsigned long)initrd.addr, initrd.size,
216		       loader_info.promptr);
217
218	/* console closed so printf in fatal below may not work */
219	fatal("Error: Linux kernel returned to zImage boot wrapper!\n\r");
220}
221