summaryrefslogtreecommitdiff
path: root/util/cbfstool/cbfs-payload-linux.c
blob: 53d455cfee53c0ca98e7381159e7fee2c125b54f (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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
/* SPDX-License-Identifier: GPL-2.0-only */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "common.h"
#include "cbfs.h"
#include "linux.h"

/* trampoline */
extern unsigned char trampoline[];
extern unsigned int trampoline_len;

/*
 * Current max number of segments include:
 *
 * 1. parameters
 * 2. kernel
 * 3. trampoline
 * 4. optional cmdline
 * 5. optional initrd
 * 6. terminating entry segment
 */
#define MAX_NUM_SEGMENTS 6

struct bzpayload {
	/* Input variables. */
	int num_segments;
	struct cbfs_payload_segment segs[MAX_NUM_SEGMENTS];
	struct buffer parameters;
	struct buffer kernel;
	struct buffer trampoline;
	struct buffer cmdline;
	struct buffer initrd;
	/* Output variables. */
	enum cbfs_compression algo;
	comp_func_ptr compress;
	struct buffer output;
	size_t offset;
	struct cbfs_payload_segment *out_seg;
};

static int bzp_init(struct bzpayload *bzp, enum cbfs_compression algo)
{
	memset(bzp, 0, sizeof(*bzp));

	/*
	 * Need at least the terminating entry segment.
	 */
	bzp->num_segments = 1;

	bzp->algo = algo;
	bzp->compress = compression_function(algo);
	if (bzp->compress == NULL) {
		ERROR("Invalid compression algorithm specified.\n");
		return -1;
	}

	return 0;
}

static int bzp_add_initrd(struct bzpayload *bzp, const char *fname)
{
	if (fname == NULL)
		return 0;

	if (buffer_from_file(&bzp->initrd, fname)) {
		ERROR("could not open initrd.\n");
		return -1;
	}

	bzp->num_segments++;

	return 0;
}

static void bzp_add_segment(struct bzpayload *bzp, struct buffer *b, void *data,
                            size_t size)
{
	buffer_init(b, NULL, data, size);
	bzp->num_segments++;
}

static int bzp_add_trampoline(struct bzpayload *bzp)
{
	bzp_add_segment(bzp, &bzp->trampoline, trampoline,
			trampoline_len);
	return 0;
}

static int bzp_add_cmdline(struct bzpayload *bzp, char *cmdline)
{
	if (cmdline == NULL)
		return 0;

	bzp_add_segment(bzp, &bzp->cmdline, cmdline, strlen(cmdline) + 1);

	return 0;
}

static int bzp_add_params(struct bzpayload *bzp, struct linux_params *params)
{
	bzp_add_segment(bzp, &bzp->parameters, params, sizeof(*params));

	return 0;
}

static int bzp_add_kernel(struct bzpayload *bzp, const struct buffer *in,
                          size_t setup_size)
{
	char *input = buffer_get(in);
	size_t kern_sz = buffer_size(in) - setup_size;

	bzp_add_segment(bzp, &bzp->kernel, &input[setup_size], kern_sz);

	return 0;
}

static int bzp_init_output(struct bzpayload *bzp, const char *name)
{
	size_t sz = 0;

	sz += buffer_size(&bzp->parameters);
	sz += buffer_size(&bzp->kernel);
	sz += buffer_size(&bzp->trampoline);
	sz += buffer_size(&bzp->cmdline);
	sz += buffer_size(&bzp->initrd);

	bzp->offset = bzp->num_segments * sizeof(struct cbfs_payload_segment);
	sz += bzp->offset;

	if (buffer_create(&bzp->output, sz, name) != 0)
		return -1;

	bzp->out_seg = &bzp->segs[0];

	return 0;
}

static void bzp_output_segment(struct bzpayload *bzp, struct buffer *b,
                               uint32_t type, uint64_t load_addr)
{
	struct buffer out;
	struct cbfs_payload_segment *seg;
	int len = 0;

	/* Don't process empty buffers. */
	if (b != NULL && buffer_size(b) == 0)
		return;

	seg = bzp->out_seg;
	seg->type = type;
	seg->load_addr = load_addr;
	bzp->out_seg++;

	/* No buffer associated with segment. */
	if (b == NULL)
		return;

	/* Use a temp buffer for easier management. */
	buffer_splice(&out, &bzp->output, bzp->offset, buffer_size(b));

	seg->mem_len = buffer_size(b);
	seg->offset = bzp->offset;
	bzp->compress(buffer_get(b), buffer_size(b), buffer_get(&out), &len);
	seg->compression = bzp->algo;
	seg->len = len;

	/* Update output offset. */
	bzp->offset += len;
}

/* TODO:
 *   handle special arguments
 *     mem= argument - only affects loading decisions (kernel + initrd), not e820 -> build time
 *     vga= argument (FILO ignores this)
 *   add support for more parameters to trampoline:
 *     alt_mem_k, ext_mem_k (not strictly necessary since e820 takes precedence)
 *     framebuffer/console values
 *
 *  larger work:
 *     is compress() safe to use in a size constrained buffer? ie. do(es) the
 *     compression algorithm(s) stop once the compression result reaches input
 *     size (ie. incompressible data)?
 */
int parse_bzImage_to_payload(const struct buffer *input,
			     struct buffer *output, const char *initrd_name,
			     char *cmdline, enum cbfs_compression algo)
{
	struct bzpayload bzp;
	unsigned int initrd_base = 64*1024*1024;
	struct linux_header *hdr = (struct linux_header *)input->data;
	unsigned int setup_size = 4 * 512;

	if (bzp_init(&bzp, algo) != 0)
		return -1;

	if (bzp_add_trampoline(&bzp) != 0)
		return -1;

	if (bzp_add_initrd(&bzp, initrd_name) != 0)
		return -1;

	if (bzp_add_cmdline(&bzp, cmdline) != 0)
		return -1;

	if (hdr->setup_sects != 0) {
		setup_size = (hdr->setup_sects + 1) * 512;
	} else {
		WARN("hdr->setup_sects is 0, which could cause boot problems.\n");
	}

	/* Setup parameter block. Imitate FILO. */
	struct linux_params params;

	memset(&params, 0, sizeof(struct linux_params));

	params.mount_root_rdonly = hdr->root_flags;
	params.orig_root_dev = hdr->root_dev;
	params.init_size = hdr->init_size;

	/* Sensible video defaults. Might be overridden on runtime by coreboot tables. */
	params.orig_video_mode = 3;
	params.orig_video_cols = 80;
	params.orig_video_lines = 25;
	params.orig_video_isVGA = 1;
	params.orig_video_points = 16;

	params.loader_type = 0xff; /* Unregistered Linux loader */

	if (cmdline != NULL) {
		if (hdr->protocol_version < 0x202) {
			params.cl_magic = CL_MAGIC_VALUE;
			params.cl_offset = COMMAND_LINE_LOC - LINUX_PARAM_LOC;
		} else {
			params.cmd_line_ptr = COMMAND_LINE_LOC;
		}
	}

	unsigned long kernel_base = 0x100000;
	if ((hdr->protocol_version < 0x200) || !(hdr->loadflags & 1)) {
		kernel_base = 0x1000; /* zImage kernel */
	}
	/* kernel prefers an address, so listen */
	if ((hdr->protocol_version >= 0x20a) && (!(hdr->pref_address >> 32))) {
		kernel_base = hdr->pref_address;
	}
	if (hdr->protocol_version >= 0x205) {
		params.relocatable_kernel = hdr->relocatable_kernel;
		params.kernel_alignment = hdr->kernel_alignment;
		if (hdr->relocatable_kernel != 0) {
			/* 16 MB should be way outside coreboot's playground,
			 * so if possible (relocatable kernel) use that to
			 * avoid a trampoline copy. */
			kernel_base = ALIGN_UP(16*1024*1024, params.kernel_alignment);
			if (hdr->init_size == 0) {
				ERROR("init_size 0 for relocatable kernel\n");
				return -1;
			}
		}
	}

	/* We have a trampoline and use that, but it can simply use
	 * this information for its jump to real Linux. */
	params.kernel_start = kernel_base;

	/* To make decisions based on the protocol version,
	   copy that as well. */
	params.param_block_version = hdr->protocol_version;

	if (bzp_add_kernel(&bzp, input, setup_size) != 0)
		return -1;

	if (buffer_size(&bzp.initrd) != 0) {
		/* TODO: this is a bit of a hack. Linux recommends to store
		 * initrd near to end-of-mem, but that's hard to do on build
		 * time. It definitely fails to read the image if it's too
		 * close to the kernel, so give it some room.
		 */
		initrd_base = kernel_base + buffer_size(&bzp.kernel);
		initrd_base = ALIGN_UP(initrd_base, 64*1024*1024);

		params.initrd_start = initrd_base;
		params.initrd_size = buffer_size(&bzp.initrd);
	}

	if (bzp_add_params(&bzp, &params) != 0)
		return -1;

	if (bzp_init_output(&bzp, input->name) != 0)
		return -1;

	/* parameter block */
	bzp_output_segment(&bzp, &bzp.parameters,
	                   PAYLOAD_SEGMENT_DATA, LINUX_PARAM_LOC);

	/* code block */
	bzp_output_segment(&bzp, &bzp.kernel,
	                   PAYLOAD_SEGMENT_CODE, kernel_base);

	/* trampoline */
	bzp_output_segment(&bzp, &bzp.trampoline,
	                   PAYLOAD_SEGMENT_CODE, TRAMPOLINE_ENTRY_LOC);

	/* cmdline */
	bzp_output_segment(&bzp, &bzp.cmdline,
	                   PAYLOAD_SEGMENT_DATA, COMMAND_LINE_LOC);

	/* initrd */
	bzp_output_segment(&bzp, &bzp.initrd,
	                   PAYLOAD_SEGMENT_DATA, initrd_base);

	/* Terminating entry segment. */
	bzp_output_segment(&bzp, NULL, PAYLOAD_SEGMENT_ENTRY, TRAMPOLINE_ENTRY_LOC);

	/* Set size of buffer taking into account potential compression. */
	buffer_set_size(&bzp.output, bzp.offset);
	/* Make passed-in output buffer be valid. */
	buffer_clone(output, &bzp.output);

	/* Serialize the segments with the correct encoding. */
	xdr_segs(output, bzp.segs, bzp.num_segments);
	return 0;
}