xref: /openbmc/linux/arch/powerpc/boot/main.c (revision b737eecd)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) Paul Mackerras 1997.
4  *
5  * Updates for PPC64 by Todd Inglett, Dave Engebretsen & Peter Bergner.
6  */
7 #include <stdarg.h>
8 #include <stddef.h>
9 #include "elf.h"
10 #include "page.h"
11 #include "string.h"
12 #include "stdio.h"
13 #include "ops.h"
14 #include "reg.h"
15 
16 struct addr_range {
17 	void *addr;
18 	unsigned long size;
19 };
20 
21 #undef DEBUG
22 
23 static struct addr_range prep_kernel(void)
24 {
25 	char elfheader[256];
26 	unsigned char *vmlinuz_addr = (unsigned char *)_vmlinux_start;
27 	unsigned long vmlinuz_size = _vmlinux_end - _vmlinux_start;
28 	void *addr = 0;
29 	struct elf_info ei;
30 	long len;
31 	int uncompressed_image = 0;
32 
33 	len = partial_decompress(vmlinuz_addr, vmlinuz_size,
34 		elfheader, sizeof(elfheader), 0);
35 	/* assume uncompressed data if -1 is returned */
36 	if (len == -1) {
37 		uncompressed_image = 1;
38 		memcpy(elfheader, vmlinuz_addr, sizeof(elfheader));
39 		printf("No valid compressed data found, assume uncompressed data\n\r");
40 	}
41 
42 	if (!parse_elf64(elfheader, &ei) && !parse_elf32(elfheader, &ei))
43 		fatal("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
44 
45 	if (platform_ops.image_hdr)
46 		platform_ops.image_hdr(elfheader);
47 
48 	/* We need to alloc the memsize: gzip will expand the kernel
49 	 * text/data, then possible rubbish we don't care about. But
50 	 * the kernel bss must be claimed (it will be zero'd by the
51 	 * kernel itself)
52 	 */
53 	printf("Allocating 0x%lx bytes for kernel...\n\r", ei.memsize);
54 
55 	if (platform_ops.vmlinux_alloc) {
56 		addr = platform_ops.vmlinux_alloc(ei.memsize);
57 	} else {
58 		/*
59 		 * Check if the kernel image (without bss) would overwrite the
60 		 * bootwrapper. The device tree has been moved in fdt_init()
61 		 * to an area allocated with malloc() (somewhere past _end).
62 		 */
63 		if ((unsigned long)_start < ei.loadsize)
64 			fatal("Insufficient memory for kernel at address 0!"
65 			       " (_start=%p, uncompressed size=%08lx)\n\r",
66 			       _start, ei.loadsize);
67 
68 		if ((unsigned long)_end < ei.memsize)
69 			fatal("The final kernel image would overwrite the "
70 					"device tree\n\r");
71 	}
72 
73 	if (uncompressed_image) {
74 		memcpy(addr, vmlinuz_addr + ei.elfoffset, ei.loadsize);
75 		printf("0x%lx bytes of uncompressed data copied\n\r",
76 		       ei.loadsize);
77 		goto out;
78 	}
79 
80 	/* Finally, decompress the kernel */
81 	printf("Decompressing (0x%p <- 0x%p:0x%p)...\n\r", addr,
82 	       vmlinuz_addr, vmlinuz_addr+vmlinuz_size);
83 
84 	len = partial_decompress(vmlinuz_addr, vmlinuz_size,
85 		addr, ei.loadsize, ei.elfoffset);
86 
87 	if (len < 0)
88 		fatal("Decompression failed with error code %ld\n\r", len);
89 
90 	if (len != ei.loadsize)
91 		 fatal("Decompression error: got 0x%lx bytes, expected 0x%lx.\n\r",
92 			 len, ei.loadsize);
93 
94 	printf("Done! Decompressed 0x%lx bytes\n\r", len);
95 out:
96 	flush_cache(addr, ei.loadsize);
97 
98 	return (struct addr_range){addr, ei.memsize};
99 }
100 
101 static struct addr_range prep_initrd(struct addr_range vmlinux, void *chosen,
102 				     unsigned long initrd_addr,
103 				     unsigned long initrd_size)
104 {
105 	/* If we have an image attached to us, it overrides anything
106 	 * supplied by the loader. */
107 	if (&_initrd_end > &_initrd_start) {
108 		printf("Attached initrd image at 0x%p-0x%p\n\r",
109 		       _initrd_start, _initrd_end);
110 		initrd_addr = (unsigned long)_initrd_start;
111 		initrd_size = _initrd_end - _initrd_start;
112 	} else if (initrd_size > 0) {
113 		printf("Using loader supplied ramdisk at 0x%lx-0x%lx\n\r",
114 		       initrd_addr, initrd_addr + initrd_size);
115 	}
116 
117 	/* If there's no initrd at all, we're done */
118 	if (! initrd_size)
119 		return (struct addr_range){0, 0};
120 
121 	/*
122 	 * If the initrd is too low it will be clobbered when the
123 	 * kernel relocates to its final location.  In this case,
124 	 * allocate a safer place and move it.
125 	 */
126 	if (initrd_addr < vmlinux.size) {
127 		void *old_addr = (void *)initrd_addr;
128 
129 		printf("Allocating 0x%lx bytes for initrd ...\n\r",
130 		       initrd_size);
131 		initrd_addr = (unsigned long)malloc(initrd_size);
132 		if (! initrd_addr)
133 			fatal("Can't allocate memory for initial "
134 			       "ramdisk !\n\r");
135 		printf("Relocating initrd 0x%lx <- 0x%p (0x%lx bytes)\n\r",
136 		       initrd_addr, old_addr, initrd_size);
137 		memmove((void *)initrd_addr, old_addr, initrd_size);
138 	}
139 
140 	printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd_addr));
141 
142 	/* Tell the kernel initrd address via device tree */
143 	setprop_val(chosen, "linux,initrd-start", (u32)(initrd_addr));
144 	setprop_val(chosen, "linux,initrd-end", (u32)(initrd_addr+initrd_size));
145 
146 	return (struct addr_range){(void *)initrd_addr, initrd_size};
147 }
148 
149 #ifdef __powerpc64__
150 static void prep_esm_blob(struct addr_range vmlinux, void *chosen)
151 {
152 	unsigned long esm_blob_addr, esm_blob_size;
153 
154 	/* Do we have an ESM (Enter Secure Mode) blob? */
155 	if (&_esm_blob_end <= &_esm_blob_start)
156 		return;
157 
158 	printf("Attached ESM blob at 0x%p-0x%p\n\r",
159 	       _esm_blob_start, _esm_blob_end);
160 	esm_blob_addr = (unsigned long)_esm_blob_start;
161 	esm_blob_size = _esm_blob_end - _esm_blob_start;
162 
163 	/*
164 	 * If the ESM blob is too low it will be clobbered when the
165 	 * kernel relocates to its final location.  In this case,
166 	 * allocate a safer place and move it.
167 	 */
168 	if (esm_blob_addr < vmlinux.size) {
169 		void *old_addr = (void *)esm_blob_addr;
170 
171 		printf("Allocating 0x%lx bytes for esm_blob ...\n\r",
172 		       esm_blob_size);
173 		esm_blob_addr = (unsigned long)malloc(esm_blob_size);
174 		if (!esm_blob_addr)
175 			fatal("Can't allocate memory for ESM blob !\n\r");
176 		printf("Relocating ESM blob 0x%lx <- 0x%p (0x%lx bytes)\n\r",
177 		       esm_blob_addr, old_addr, esm_blob_size);
178 		memmove((void *)esm_blob_addr, old_addr, esm_blob_size);
179 	}
180 
181 	/* Tell the kernel ESM blob address via device tree. */
182 	setprop_val(chosen, "linux,esm-blob-start", (u32)(esm_blob_addr));
183 	setprop_val(chosen, "linux,esm-blob-end", (u32)(esm_blob_addr + esm_blob_size));
184 }
185 #else
186 static inline void prep_esm_blob(struct addr_range vmlinux, void *chosen) { }
187 #endif
188 
189 /* A buffer that may be edited by tools operating on a zImage binary so as to
190  * edit the command line passed to vmlinux (by setting /chosen/bootargs).
191  * The buffer is put in it's own section so that tools may locate it easier.
192  */
193 static char cmdline[BOOT_COMMAND_LINE_SIZE]
194 	__attribute__((__section__("__builtin_cmdline")));
195 
196 static void prep_cmdline(void *chosen)
197 {
198 	unsigned int getline_timeout = 5000;
199 	int v;
200 	int n;
201 
202 	/* Wait-for-input time */
203 	n = getprop(chosen, "linux,cmdline-timeout", &v, sizeof(v));
204 	if (n == sizeof(v))
205 		getline_timeout = v;
206 
207 	if (cmdline[0] == '\0')
208 		getprop(chosen, "bootargs", cmdline, BOOT_COMMAND_LINE_SIZE-1);
209 
210 	printf("\n\rLinux/PowerPC load: %s", cmdline);
211 
212 	/* If possible, edit the command line */
213 	if (console_ops.edit_cmdline && getline_timeout)
214 		console_ops.edit_cmdline(cmdline, BOOT_COMMAND_LINE_SIZE, getline_timeout);
215 
216 	printf("\n\r");
217 
218 	/* Put the command line back into the devtree for the kernel */
219 	setprop_str(chosen, "bootargs", cmdline);
220 }
221 
222 struct platform_ops platform_ops;
223 struct dt_ops dt_ops;
224 struct console_ops console_ops;
225 struct loader_info loader_info;
226 
227 void start(void)
228 {
229 	struct addr_range vmlinux, initrd;
230 	kernel_entry_t kentry;
231 	unsigned long ft_addr = 0;
232 	void *chosen;
233 
234 	/* Do this first, because malloc() could clobber the loader's
235 	 * command line.  Only use the loader command line if a
236 	 * built-in command line wasn't set by an external tool */
237 	if ((loader_info.cmdline_len > 0) && (cmdline[0] == '\0'))
238 		memmove(cmdline, loader_info.cmdline,
239 			min(loader_info.cmdline_len, BOOT_COMMAND_LINE_SIZE-1));
240 
241 	if (console_ops.open && (console_ops.open() < 0))
242 		exit();
243 	if (platform_ops.fixups)
244 		platform_ops.fixups();
245 
246 	printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
247 	       _start, get_sp());
248 
249 	/* Ensure that the device tree has a /chosen node */
250 	chosen = finddevice("/chosen");
251 	if (!chosen)
252 		chosen = create_node(NULL, "chosen");
253 
254 	vmlinux = prep_kernel();
255 	initrd = prep_initrd(vmlinux, chosen,
256 			     loader_info.initrd_addr, loader_info.initrd_size);
257 	prep_esm_blob(vmlinux, chosen);
258 	prep_cmdline(chosen);
259 
260 	printf("Finalizing device tree...");
261 	if (dt_ops.finalize)
262 		ft_addr = dt_ops.finalize();
263 	if (ft_addr)
264 		printf(" flat tree at 0x%lx\n\r", ft_addr);
265 	else
266 		printf(" using OF tree (promptr=%p)\n\r", loader_info.promptr);
267 
268 	if (console_ops.close)
269 		console_ops.close();
270 
271 	kentry = (kernel_entry_t) vmlinux.addr;
272 	if (ft_addr) {
273 		if(platform_ops.kentry)
274 			platform_ops.kentry(ft_addr, vmlinux.addr);
275 		else
276 			kentry(ft_addr, 0, NULL);
277 	}
278 	else
279 		kentry((unsigned long)initrd.addr, initrd.size,
280 		       loader_info.promptr);
281 
282 	/* console closed so printf in fatal below may not work */
283 	fatal("Error: Linux kernel returned to zImage boot wrapper!\n\r");
284 }
285