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		/*
60		 * Check if the kernel image (without bss) would overwrite the
61		 * bootwrapper. The device tree has been moved in fdt_init()
62		 * to an area allocated with malloc() (somewhere past _end).
63		 */
64		if ((unsigned long)_start < ei.loadsize)
65			fatal("Insufficient memory for kernel at address 0!"
66			       " (_start=%p, uncompressed size=%08lx)\n\r",
67			       _start, ei.loadsize);
68
69		if ((unsigned long)_end < ei.memsize)
70			fatal("The final kernel image would overwrite the "
71					"device tree\n\r");
72	}
73
74	/* Finally, gunzip the kernel */
75	printf("gunzipping (0x%p <- 0x%p:0x%p)...", addr,
76	       vmlinuz_addr, vmlinuz_addr+vmlinuz_size);
77	/* discard up to the actual load data */
78	gunzip_discard(&gzstate, ei.elfoffset - sizeof(elfheader));
79	len = gunzip_finish(&gzstate, addr, ei.loadsize);
80	if (len != ei.loadsize)
81		fatal("ran out of data!  only got 0x%x of 0x%lx bytes.\n\r",
82				len, ei.loadsize);
83	printf("done 0x%x bytes\n\r", len);
84
85	flush_cache(addr, ei.loadsize);
86
87	return (struct addr_range){addr, ei.memsize};
88}
89
90static struct addr_range prep_initrd(struct addr_range vmlinux, void *chosen,
91				     unsigned long initrd_addr,
92				     unsigned long initrd_size)
93{
94	/* If we have an image attached to us, it overrides anything
95	 * supplied by the loader. */
96	if (_initrd_end > _initrd_start) {
97		printf("Attached initrd image at 0x%p-0x%p\n\r",
98		       _initrd_start, _initrd_end);
99		initrd_addr = (unsigned long)_initrd_start;
100		initrd_size = _initrd_end - _initrd_start;
101	} else if (initrd_size > 0) {
102		printf("Using loader supplied ramdisk at 0x%lx-0x%lx\n\r",
103		       initrd_addr, initrd_addr + initrd_size);
104	}
105
106	/* If there's no initrd at all, we're done */
107	if (! initrd_size)
108		return (struct addr_range){0, 0};
109
110	/*
111	 * If the initrd is too low it will be clobbered when the
112	 * kernel relocates to its final location.  In this case,
113	 * allocate a safer place and move it.
114	 */
115	if (initrd_addr < vmlinux.size) {
116		void *old_addr = (void *)initrd_addr;
117
118		printf("Allocating 0x%lx bytes for initrd ...\n\r",
119		       initrd_size);
120		initrd_addr = (unsigned long)malloc(initrd_size);
121		if (! initrd_addr)
122			fatal("Can't allocate memory for initial "
123			       "ramdisk !\n\r");
124		printf("Relocating initrd 0x%lx <- 0x%p (0x%lx bytes)\n\r",
125		       initrd_addr, old_addr, initrd_size);
126		memmove((void *)initrd_addr, old_addr, initrd_size);
127	}
128
129	printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd_addr));
130
131	/* Tell the kernel initrd address via device tree */
132	setprop_val(chosen, "linux,initrd-start", (u32)(initrd_addr));
133	setprop_val(chosen, "linux,initrd-end", (u32)(initrd_addr+initrd_size));
134
135	return (struct addr_range){(void *)initrd_addr, initrd_size};
136}
137
138/* A buffer that may be edited by tools operating on a zImage binary so as to
139 * edit the command line passed to vmlinux (by setting /chosen/bootargs).
140 * The buffer is put in it's own section so that tools may locate it easier.
141 */
142static char cmdline[BOOT_COMMAND_LINE_SIZE]
143	__attribute__((__section__("__builtin_cmdline")));
144
145static void prep_cmdline(void *chosen)
146{
147	unsigned int getline_timeout = 5000;
148	int v;
149	int n;
150
151	/* Wait-for-input time */
152	n = getprop(chosen, "linux,cmdline-timeout", &v, sizeof(v));
153	if (n == sizeof(v))
154		getline_timeout = v;
155
156	if (cmdline[0] == '\0')
157		getprop(chosen, "bootargs", cmdline, BOOT_COMMAND_LINE_SIZE-1);
158
159	printf("\n\rLinux/PowerPC load: %s", cmdline);
160
161	/* If possible, edit the command line */
162	if (console_ops.edit_cmdline && getline_timeout)
163		console_ops.edit_cmdline(cmdline, BOOT_COMMAND_LINE_SIZE, getline_timeout);
164
165	printf("\n\r");
166
167	/* Put the command line back into the devtree for the kernel */
168	setprop_str(chosen, "bootargs", cmdline);
169}
170
171struct platform_ops platform_ops;
172struct dt_ops dt_ops;
173struct console_ops console_ops;
174struct loader_info loader_info;
175
176void start(void)
177{
178	struct addr_range vmlinux, initrd;
179	kernel_entry_t kentry;
180	unsigned long ft_addr = 0;
181	void *chosen;
182
183	/* Do this first, because malloc() could clobber the loader's
184	 * command line.  Only use the loader command line if a
185	 * built-in command line wasn't set by an external tool */
186	if ((loader_info.cmdline_len > 0) && (cmdline[0] == '\0'))
187		memmove(cmdline, loader_info.cmdline,
188			min(loader_info.cmdline_len, BOOT_COMMAND_LINE_SIZE-1));
189
190	if (console_ops.open && (console_ops.open() < 0))
191		exit();
192	if (platform_ops.fixups)
193		platform_ops.fixups();
194
195	printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
196	       _start, get_sp());
197
198	/* Ensure that the device tree has a /chosen node */
199	chosen = finddevice("/chosen");
200	if (!chosen)
201		chosen = create_node(NULL, "chosen");
202
203	vmlinux = prep_kernel();
204	initrd = prep_initrd(vmlinux, chosen,
205			     loader_info.initrd_addr, loader_info.initrd_size);
206	prep_cmdline(chosen);
207
208	printf("Finalizing device tree...");
209	if (dt_ops.finalize)
210		ft_addr = dt_ops.finalize();
211	if (ft_addr)
212		printf(" flat tree at 0x%lx\n\r", ft_addr);
213	else
214		printf(" using OF tree (promptr=%p)\n\r", loader_info.promptr);
215
216	if (console_ops.close)
217		console_ops.close();
218
219	kentry = (kernel_entry_t) vmlinux.addr;
220	if (ft_addr)
221		kentry(ft_addr, 0, NULL);
222	else
223		kentry((unsigned long)initrd.addr, initrd.size,
224		       loader_info.promptr);
225
226	/* console closed so printf in fatal below may not work */
227	fatal("Error: Linux kernel returned to zImage boot wrapper!\n\r");
228}
229