[people/ms/u-boot.git] / tools / mips-relocs.c

/*
 * MIPS Relocation Data Generator
 *
 * Copyright (c) 2017 Imagination Technologies Ltd.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <assert.h>
#include <elf.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>

#include <asm/relocs.h>

#define hdr_field(pfx, idx, field) ({				\
	uint64_t _val;						\
	unsigned int _size;					\
								\
	if (is_64) {						\
		_val = pfx##hdr64[idx].field;			\
		_size = sizeof(pfx##hdr64[0].field);		\
	} else {						\
		_val = pfx##hdr32[idx].field;			\
		_size = sizeof(pfx##hdr32[0].field);		\
	}							\
								\
	switch (_size) {					\
	case 1:							\
		break;						\
	case 2:							\
		_val = is_be ? be16toh(_val) : le16toh(_val);	\
		break;						\
	case 4:							\
		_val = is_be ? be32toh(_val) : le32toh(_val);	\
		break;						\
	case 8:							\
		_val = is_be ? be64toh(_val) : le64toh(_val);	\
		break;						\
	}							\
								\
	_val;							\
})

#define set_hdr_field(pfx, idx, field, val) ({			\
	uint64_t _val;						\
	unsigned int _size;					\
								\
	if (is_64)						\
		_size = sizeof(pfx##hdr64[0].field);		\
	else							\
		_size = sizeof(pfx##hdr32[0].field);		\
								\
	switch (_size) {					\
	case 1:							\
		_val = val;					\
		break;						\
	case 2:							\
		_val = is_be ? htobe16(val) : htole16(val);	\
		break;						\
	case 4:							\
		_val = is_be ? htobe32(val) : htole32(val);	\
		break;						\
	case 8:							\
		_val = is_be ? htobe64(val) : htole64(val);	\
		break;						\
	default:						\
		/* We should never reach here */		\
		_val = 0;					\
		assert(0);					\
		break;						\
	}							\
								\
	if (is_64)						\
		pfx##hdr64[idx].field = _val;			\
	else							\
		pfx##hdr32[idx].field = _val;			\
})

#define ehdr_field(field) \
	hdr_field(e, 0, field)
#define phdr_field(idx, field) \
	hdr_field(p, idx, field)
#define shdr_field(idx, field) \
	hdr_field(s, idx, field)

#define set_phdr_field(idx, field, val) \
	set_hdr_field(p, idx, field, val)
#define set_shdr_field(idx, field, val) \
	set_hdr_field(s, idx, field, val)

#define shstr(idx) (&shstrtab[idx])

bool is_64, is_be;
uint64_t text_base;

struct mips_reloc {
	uint8_t type;
	uint64_t offset;
} *relocs;
size_t relocs_sz, relocs_idx;

static int add_reloc(unsigned int type, uint64_t off)
{
	struct mips_reloc *new;
	size_t new_sz;

	switch (type) {
	case R_MIPS_NONE:
	case R_MIPS_LO16:
	case R_MIPS_PC16:
	case R_MIPS_HIGHER:
	case R_MIPS_HIGHEST:
	case R_MIPS_PC21_S2:
	case R_MIPS_PC26_S2:
		/* Skip these relocs */
		return 0;

	default:
		break;
	}

	if (relocs_idx == relocs_sz) {
		new_sz = relocs_sz ? relocs_sz * 2 : 128;
		new = realloc(relocs, new_sz * sizeof(*relocs));
		if (!new) {
			fprintf(stderr, "Out of memory\n");
			return -ENOMEM;
		}

		relocs = new;
		relocs_sz = new_sz;
	}

	relocs[relocs_idx++] = (struct mips_reloc){
		.type = type,
		.offset = off,
	};

	return 0;
}

static int parse_mips32_rel(const void *_rel)
{
	const Elf32_Rel *rel = _rel;
	uint32_t off, type;

	off = is_be ? be32toh(rel->r_offset) : le32toh(rel->r_offset);
	off -= text_base;

	type = is_be ? be32toh(rel->r_info) : le32toh(rel->r_info);
	type = ELF32_R_TYPE(type);

	return add_reloc(type, off);
}

static int parse_mips64_rela(const void *_rel)
{
	const Elf64_Rela *rel = _rel;
	uint64_t off, type;

	off = is_be ? be64toh(rel->r_offset) : le64toh(rel->r_offset);
	off -= text_base;

	type = rel->r_info >> (64 - 8);

	return add_reloc(type, off);
}

static void output_uint(uint8_t **buf, uint64_t val)
{
	uint64_t tmp;

	do {
		tmp = val & 0x7f;
		val >>= 7;
		tmp |= !!val << 7;
		*(*buf)++ = tmp;
	} while (val);
}

static int compare_relocs(const void *a, const void *b)
{
	const struct mips_reloc *ra = a, *rb = b;

	return ra->offset - rb->offset;
}

int main(int argc, char *argv[])
{
	unsigned int i, j, i_rel_shdr, sh_type, sh_entsize, sh_entries;
	size_t rel_size, rel_actual_size, load_sz;
	const char *shstrtab, *sh_name, *rel_pfx;
	int (*parse_fn)(const void *rel);
	uint8_t *buf_start, *buf;
	const Elf32_Ehdr *ehdr32;
	const Elf64_Ehdr *ehdr64;
	uintptr_t sh_offset;
	Elf32_Phdr *phdr32;
	Elf64_Phdr *phdr64;
	Elf32_Shdr *shdr32;
	Elf64_Shdr *shdr64;
	struct stat st;
	int err, fd;
	void *elf;
	bool skip;

	fd = open(argv[1], O_RDWR);
	if (fd == -1) {
		fprintf(stderr, "Unable to open input file %s\n", argv[1]);
		err = errno;
		goto out_ret;
	}

	err = fstat(fd, &st);
	if (err) {
		fprintf(stderr, "Unable to fstat() input file\n");
		goto out_close_fd;
	}

	elf = mmap(NULL, st.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
	if (elf == MAP_FAILED) {
		fprintf(stderr, "Unable to mmap() input file\n");
		err = errno;
		goto out_close_fd;
	}

	ehdr32 = elf;
	ehdr64 = elf;

	if (memcmp(&ehdr32->e_ident[EI_MAG0], ELFMAG, SELFMAG)) {
		fprintf(stderr, "Input file is not an ELF\n");
		err = -EINVAL;
		goto out_free_relocs;
	}

	if (ehdr32->e_ident[EI_VERSION] != EV_CURRENT) {
		fprintf(stderr, "Unrecognised ELF version\n");
		err = -EINVAL;
		goto out_free_relocs;
	}

	switch (ehdr32->e_ident[EI_CLASS]) {
	case ELFCLASS32:
		is_64 = false;
		break;
	case ELFCLASS64:
		is_64 = true;
		break;
	default:
		fprintf(stderr, "Unrecognised ELF class\n");
		err = -EINVAL;
		goto out_free_relocs;
	}

	switch (ehdr32->e_ident[EI_DATA]) {
	case ELFDATA2LSB:
		is_be = false;
		break;
	case ELFDATA2MSB:
		is_be = true;
		break;
	default:
		fprintf(stderr, "Unrecognised ELF data encoding\n");
		err = -EINVAL;
		goto out_free_relocs;
	}

	if (ehdr_field(e_type) != ET_EXEC) {
		fprintf(stderr, "Input ELF is not an executable\n");
		printf("type 0x%lx\n", ehdr_field(e_type));
		err = -EINVAL;
		goto out_free_relocs;
	}

	if (ehdr_field(e_machine) != EM_MIPS) {
		fprintf(stderr, "Input ELF does not target MIPS\n");
		err = -EINVAL;
		goto out_free_relocs;
	}

	phdr32 = elf + ehdr_field(e_phoff);
	phdr64 = elf + ehdr_field(e_phoff);
	shdr32 = elf + ehdr_field(e_shoff);
	shdr64 = elf + ehdr_field(e_shoff);
	shstrtab = elf + shdr_field(ehdr_field(e_shstrndx), sh_offset);

	i_rel_shdr = UINT_MAX;
	for (i = 0; i < ehdr_field(e_shnum); i++) {
		sh_name = shstr(shdr_field(i, sh_name));

		if (!strcmp(sh_name, ".rel")) {
			i_rel_shdr = i;
			continue;
		}

		if (!strcmp(sh_name, ".text")) {
			text_base = shdr_field(i, sh_addr);
			continue;
		}
	}
	if (i_rel_shdr == UINT_MAX) {
		fprintf(stderr, "Unable to find .rel section\n");
		err = -EINVAL;
		goto out_free_relocs;
	}
	if (!text_base) {
		fprintf(stderr, "Unable to find .text base address\n");
		err = -EINVAL;
		goto out_free_relocs;
	}

	rel_pfx = is_64 ? ".rela." : ".rel.";

	for (i = 0; i < ehdr_field(e_shnum); i++) {
		sh_type = shdr_field(i, sh_type);
		if ((sh_type != SHT_REL) && (sh_type != SHT_RELA))
			continue;

		sh_name = shstr(shdr_field(i, sh_name));
		if (strncmp(sh_name, rel_pfx, strlen(rel_pfx))) {
			if (strcmp(sh_name, ".rel") && strcmp(sh_name, ".rel.dyn"))
				fprintf(stderr, "WARNING: Unexpected reloc section name '%s'\n", sh_name);
			continue;
		}

		/*
		 * Skip reloc sections which either don't correspond to another
		 * section in the ELF, or whose corresponding section isn't
		 * loaded as part of the U-Boot binary (ie. doesn't have the
		 * alloc flags set).
		 */
		skip = true;
		for (j = 0; j < ehdr_field(e_shnum); j++) {
			if (strcmp(&sh_name[strlen(rel_pfx) - 1], shstr(shdr_field(j, sh_name))))
				continue;

			skip = !(shdr_field(j, sh_flags) & SHF_ALLOC);
			break;
		}
		if (skip)
			continue;

		sh_offset = shdr_field(i, sh_offset);
		sh_entsize = shdr_field(i, sh_entsize);
		sh_entries = shdr_field(i, sh_size) / sh_entsize;

		if (sh_type == SHT_REL) {
			if (is_64) {
				fprintf(stderr, "REL-style reloc in MIPS64 ELF?\n");
				err = -EINVAL;
				goto out_free_relocs;
			} else {
				parse_fn = parse_mips32_rel;
			}
		} else {
			if (is_64) {
				parse_fn = parse_mips64_rela;
			} else {
				fprintf(stderr, "RELA-style reloc in MIPS32 ELF?\n");
				err = -EINVAL;
				goto out_free_relocs;
			}
		}

		for (j = 0; j < sh_entries; j++) {
			err = parse_fn(elf + sh_offset + (j * sh_entsize));
			if (err)
				goto out_free_relocs;
		}
	}

	/* Sort relocs in ascending order of offset */
	qsort(relocs, relocs_idx, sizeof(*relocs), compare_relocs);

	/* Make reloc offsets relative to their predecessor */
	for (i = relocs_idx - 1; i > 0; i--)
		relocs[i].offset -= relocs[i - 1].offset;

	/* Write the relocations to the .rel section */
	buf = buf_start = elf + shdr_field(i_rel_shdr, sh_offset);
	for (i = 0; i < relocs_idx; i++) {
		output_uint(&buf, relocs[i].type);
		output_uint(&buf, relocs[i].offset >> 2);
	}

	/* Write a terminating R_MIPS_NONE (0) */
	output_uint(&buf, R_MIPS_NONE);

	/* Ensure the relocs didn't overflow the .rel section */
	rel_size = shdr_field(i_rel_shdr, sh_size);
	rel_actual_size = buf - buf_start;
	if (rel_actual_size > rel_size) {
		fprintf(stderr, "Relocs overflowed .rel section\n");
		return -ENOMEM;
	}

	/* Update the .rel section's size */
	set_shdr_field(i_rel_shdr, sh_size, rel_actual_size);

	/* Shrink the PT_LOAD program header filesz (ie. shrink u-boot.bin) */
	for (i = 0; i < ehdr_field(e_phnum); i++) {
		if (phdr_field(i, p_type) != PT_LOAD)
			continue;

		load_sz = phdr_field(i, p_filesz);
		load_sz -= rel_size - rel_actual_size;
		set_phdr_field(i, p_filesz, load_sz);
		break;
	}

	/* Make sure data is written back to the file */
	err = msync(elf, st.st_size, MS_SYNC);
	if (err) {
		fprintf(stderr, "Failed to msync: %d\n", errno);
		goto out_free_relocs;
	}

out_free_relocs:
	free(relocs);
	munmap(elf, st.st_size);
out_close_fd:
	close(fd);
out_ret:
	return err;
}
Commit	Line	Data
703ec9dd PB	1	/*
	2	* MIPS Relocation Data Generator
	3	*
	4	* Copyright (c) 2017 Imagination Technologies Ltd.
	5	*
	6	* SPDX-License-Identifier: GPL-2.0+
	7	*/
	8
e94136bd	9	#include <assert.h>
703ec9dd PB	10	#include <elf.h>
	11	#include <errno.h>
	12	#include <fcntl.h>
	13	#include <limits.h>
d2bf1152	14	#include <stdbool.h>
703ec9dd PB	15	#include <stdio.h>
	16	#include <stdlib.h>
	17	#include <sys/mman.h>
	18	#include <sys/stat.h>
	19	#include <unistd.h>
	20
	21	#include <asm/relocs.h>
	22
	23	#define hdr_field(pfx, idx, field) ({ \
	24	uint64_t _val; \
	25	unsigned int _size; \
	26	\
	27	if (is_64) { \
	28	_val = pfx##hdr64[idx].field; \
	29	_size = sizeof(pfx##hdr64[0].field); \
	30	} else { \
	31	_val = pfx##hdr32[idx].field; \
	32	_size = sizeof(pfx##hdr32[0].field); \
	33	} \
	34	\
	35	switch (_size) { \
	36	case 1: \
	37	break; \
	38	case 2: \
	39	_val = is_be ? be16toh(_val) : le16toh(_val); \
	40	break; \
	41	case 4: \
	42	_val = is_be ? be32toh(_val) : le32toh(_val); \
	43	break; \
	44	case 8: \
	45	_val = is_be ? be64toh(_val) : le64toh(_val); \
	46	break; \
	47	} \
	48	\
	49	_val; \
	50	})
	51
	52	#define set_hdr_field(pfx, idx, field, val) ({ \
	53	uint64_t _val; \
	54	unsigned int _size; \
	55	\
	56	if (is_64) \
	57	_size = sizeof(pfx##hdr64[0].field); \
	58	else \
	59	_size = sizeof(pfx##hdr32[0].field); \
	60	\
	61	switch (_size) { \
	62	case 1: \
	63	_val = val; \
	64	break; \
	65	case 2: \
	66	_val = is_be ? htobe16(val) : htole16(val); \
	67	break; \
	68	case 4: \
	69	_val = is_be ? htobe32(val) : htole32(val); \
	70	break; \
	71	case 8: \
	72	_val = is_be ? htobe64(val) : htole64(val); \
	73	break; \
e94136bd PB	74	default: \
	75	/* We should never reach here */ \
	76	_val = 0; \
	77	assert(0); \
	78	break; \
703ec9dd PB	79	} \
	80	\
	81	if (is_64) \
	82	pfx##hdr64[idx].field = _val; \
	83	else \
	84	pfx##hdr32[idx].field = _val; \
	85	})
	86
	87	#define ehdr_field(field) \
	88	hdr_field(e, 0, field)
	89	#define phdr_field(idx, field) \
	90	hdr_field(p, idx, field)
	91	#define shdr_field(idx, field) \
	92	hdr_field(s, idx, field)
	93
	94	#define set_phdr_field(idx, field, val) \
	95	set_hdr_field(p, idx, field, val)
	96	#define set_shdr_field(idx, field, val) \
	97	set_hdr_field(s, idx, field, val)
	98
	99	#define shstr(idx) (&shstrtab[idx])
	100
	101	bool is_64, is_be;
	102	uint64_t text_base;
	103
	104	struct mips_reloc {
	105	uint8_t type;
	106	uint64_t offset;
	107	} *relocs;
	108	size_t relocs_sz, relocs_idx;
	109
	110	static int add_reloc(unsigned int type, uint64_t off)
	111	{
	112	struct mips_reloc *new;
	113	size_t new_sz;
	114
	115	switch (type) {
	116	case R_MIPS_NONE:
	117	case R_MIPS_LO16:
	118	case R_MIPS_PC16:
	119	case R_MIPS_HIGHER:
	120	case R_MIPS_HIGHEST:
	121	case R_MIPS_PC21_S2:
	122	case R_MIPS_PC26_S2:
	123	/* Skip these relocs */
	124	return 0;
	125
	126	default:
	127	break;
	128	}
	129
	130	if (relocs_idx == relocs_sz) {
	131	new_sz = relocs_sz ? relocs_sz * 2 : 128;
	132	new = realloc(relocs, new_sz * sizeof(*relocs));
	133	if (!new) {
	134	fprintf(stderr, "Out of memory\n");
	135	return -ENOMEM;
	136	}
	137
	138	relocs = new;
	139	relocs_sz = new_sz;
	140	}
	141
	142	relocs[relocs_idx++] = (struct mips_reloc){
143	.type = type,
144	.offset = off,
145	};
146
147	return 0;
148	}
149
150	static int parse_mips32_rel(const void *_rel)
151	{
152	const Elf32_Rel *rel = _rel;
153	uint32_t off, type;
154
155	off = is_be ? be32toh(rel->r_offset) : le32toh(rel->r_offset);
156	off -= text_base;
157
158	type = is_be ? be32toh(rel->r_info) : le32toh(rel->r_info);
159	type = ELF32_R_TYPE(type);
160
161	return add_reloc(type, off);
162	}
163
164	static int parse_mips64_rela(const void *_rel)
165	{
166	const Elf64_Rela *rel = _rel;
167	uint64_t off, type;
168
169	off = is_be ? be64toh(rel->r_offset) : le64toh(rel->r_offset);
170	off -= text_base;
171
172	type = rel->r_info >> (64 - 8);
173
174	return add_reloc(type, off);
175	}
176
177	static void output_uint(uint8_t **buf, uint64_t val)
178	{
179	uint64_t tmp;
180
181	do {
182	tmp = val & 0x7f;
183	val >>= 7;
184	tmp \|= !!val << 7;
185	(buf)++ = tmp;
186	} while (val);
187	}
188
189	static int compare_relocs(const void a, const void b)
190	{
191	const struct mips_reloc ra = a, rb = b;
192
193	return ra->offset - rb->offset;
194	}
195
196	int main(int argc, char *argv[])
197	{
198	unsigned int i, j, i_rel_shdr, sh_type, sh_entsize, sh_entries;
199	size_t rel_size, rel_actual_size, load_sz;
200	const char shstrtab, sh_name, *rel_pfx;
201	int (parse_fn)(const void rel);
202	uint8_t buf_start, buf;
203	const Elf32_Ehdr *ehdr32;
204	const Elf64_Ehdr *ehdr64;
205	uintptr_t sh_offset;
206	Elf32_Phdr *phdr32;
207	Elf64_Phdr *phdr64;
208	Elf32_Shdr *shdr32;
209	Elf64_Shdr *shdr64;
210	struct stat st;
211	int err, fd;
212	void *elf;
213	bool skip;
214
215	fd = open(argv[1], O_RDWR);
216	if (fd == -1) {
217	fprintf(stderr, "Unable to open input file %s\n", argv[1]);
218	err = errno;
219	goto out_ret;
220	}
221
222	err = fstat(fd, &st);
223	if (err) {
224	fprintf(stderr, "Unable to fstat() input file\n");
225	goto out_close_fd;
226	}
227
228	elf = mmap(NULL, st.st_size, PROT_READ \| PROT_WRITE, MAP_SHARED, fd, 0);
229	if (elf == MAP_FAILED) {
230	fprintf(stderr, "Unable to mmap() input file\n");
231	err = errno;
232	goto out_close_fd;
233	}
234
235	ehdr32 = elf;
236	ehdr64 = elf;
237
238	if (memcmp(&ehdr32->e_ident[EI_MAG0], ELFMAG, SELFMAG)) {
239	fprintf(stderr, "Input file is not an ELF\n");
240	err = -EINVAL;
241	goto out_free_relocs;
242	}
243
244	if (ehdr32->e_ident[EI_VERSION] != EV_CURRENT) {
245	fprintf(stderr, "Unrecognised ELF version\n");
246	err = -EINVAL;
247	goto out_free_relocs;
248	}
249
250	switch (ehdr32->e_ident[EI_CLASS]) {
251	case ELFCLASS32:
252	is_64 = false;
253	break;
254	case ELFCLASS64:
255	is_64 = true;
256	break;
257	default:
258	fprintf(stderr, "Unrecognised ELF class\n");
259	err = -EINVAL;
260	goto out_free_relocs;
261	}
262
263	switch (ehdr32->e_ident[EI_DATA]) {
264	case ELFDATA2LSB:
265	is_be = false;
266	break;
267	case ELFDATA2MSB:
268	is_be = true;
269	break;
270	default:
271	fprintf(stderr, "Unrecognised ELF data encoding\n");
272	err = -EINVAL;
273	goto out_free_relocs;
274	}
275
276	if (ehdr_field(e_type) != ET_EXEC) {
277	fprintf(stderr, "Input ELF is not an executable\n");
278	printf("type 0x%lx\n", ehdr_field(e_type));
279	err = -EINVAL;
280	goto out_free_relocs;
281	}
282
283	if (ehdr_field(e_machine) != EM_MIPS) {
284	fprintf(stderr, "Input ELF does not target MIPS\n");
285	err = -EINVAL;
286	goto out_free_relocs;
287	}
288
289	phdr32 = elf + ehdr_field(e_phoff);
290	phdr64 = elf + ehdr_field(e_phoff);
291	shdr32 = elf + ehdr_field(e_shoff);
292	shdr64 = elf + ehdr_field(e_shoff);
293	shstrtab = elf + shdr_field(ehdr_field(e_shstrndx), sh_offset);
294
295	i_rel_shdr = UINT_MAX;
296	for (i = 0; i < ehdr_field(e_shnum); i++) {
297	sh_name = shstr(shdr_field(i, sh_name));
298
299	if (!strcmp(sh_name, ".rel")) {
300	i_rel_shdr = i;
301	continue;
302	}
303
304	if (!strcmp(sh_name, ".text")) {
305	text_base = shdr_field(i, sh_addr);
306	continue;
307	}
308	}
309	if (i_rel_shdr == UINT_MAX) {
310	fprintf(stderr, "Unable to find .rel section\n");
311	err = -EINVAL;
312	goto out_free_relocs;
313	}
314	if (!text_base) {
315	fprintf(stderr, "Unable to find .text base address\n");
316	err = -EINVAL;
317	goto out_free_relocs;
318	}
319
320	rel_pfx = is_64 ? ".rela." : ".rel.";
321
322	for (i = 0; i < ehdr_field(e_shnum); i++) {
323	sh_type = shdr_field(i, sh_type);
324	if ((sh_type != SHT_REL) && (sh_type != SHT_RELA))
325	continue;
326
327	sh_name = shstr(shdr_field(i, sh_name));
328	if (strncmp(sh_name, rel_pfx, strlen(rel_pfx))) {
329	if (strcmp(sh_name, ".rel") && strcmp(sh_name, ".rel.dyn"))
330	fprintf(stderr, "WARNING: Unexpected reloc section name '%s'\n", sh_name);
331	continue;
332	}
333
334	/*
335	* Skip reloc sections which either don't correspond to another
336	* section in the ELF, or whose corresponding section isn't
337	* loaded as part of the U-Boot binary (ie. doesn't have the
338	* alloc flags set).
339	*/
340	skip = true;
341	for (j = 0; j < ehdr_field(e_shnum); j++) {
342	if (strcmp(&sh_name[strlen(rel_pfx) - 1], shstr(shdr_field(j, sh_name))))
343	continue;
344
345	skip = !(shdr_field(j, sh_flags) & SHF_ALLOC);
346	break;
347	}
348	if (skip)
349	continue;
350
351	sh_offset = shdr_field(i, sh_offset);
352	sh_entsize = shdr_field(i, sh_entsize);
353	sh_entries = shdr_field(i, sh_size) / sh_entsize;
354
355	if (sh_type == SHT_REL) {
356	if (is_64) {
357	fprintf(stderr, "REL-style reloc in MIPS64 ELF?\n");
358	err = -EINVAL;
359	goto out_free_relocs;
360	} else {
361	parse_fn = parse_mips32_rel;
362	}
363	} else {
364	if (is_64) {
365	parse_fn = parse_mips64_rela;
366	} else {
367	fprintf(stderr, "RELA-style reloc in MIPS32 ELF?\n");
368	err = -EINVAL;
369	goto out_free_relocs;
370	}
371	}
372
373	for (j = 0; j < sh_entries; j++) {
374	err = parse_fn(elf + sh_offset + (j * sh_entsize));
375	if (err)
376	goto out_free_relocs;
377	}
378	}
379
380	/* Sort relocs in ascending order of offset */
381	qsort(relocs, relocs_idx, sizeof(*relocs), compare_relocs);
382
383	/* Make reloc offsets relative to their predecessor */
384	for (i = relocs_idx - 1; i > 0; i--)
385	relocs[i].offset -= relocs[i - 1].offset;
386
387	/* Write the relocations to the .rel section */
388	buf = buf_start = elf + shdr_field(i_rel_shdr, sh_offset);
389	for (i = 0; i < relocs_idx; i++) {
390	output_uint(&buf, relocs[i].type);
391	output_uint(&buf, relocs[i].offset >> 2);
392	}
393
394	/* Write a terminating R_MIPS_NONE (0) */
395	output_uint(&buf, R_MIPS_NONE);
396
397	/* Ensure the relocs didn't overflow the .rel section */
398	rel_size = shdr_field(i_rel_shdr, sh_size);
399	rel_actual_size = buf - buf_start;
400	if (rel_actual_size > rel_size) {
401	fprintf(stderr, "Relocs overflowed .rel section\n");
402	return -ENOMEM;
403	}
404
405	/* Update the .rel section's size */
406	set_shdr_field(i_rel_shdr, sh_size, rel_actual_size);
407
408	/* Shrink the PT_LOAD program header filesz (ie. shrink u-boot.bin) */
409	for (i = 0; i < ehdr_field(e_phnum); i++) {
410	if (phdr_field(i, p_type) != PT_LOAD)
411	continue;
412
413	load_sz = phdr_field(i, p_filesz);
414	load_sz -= rel_size - rel_actual_size;
415	set_phdr_field(i, p_filesz, load_sz);
416	break;
417	}
418
419	/* Make sure data is written back to the file */
420	err = msync(elf, st.st_size, MS_SYNC);
421	if (err) {
422	fprintf(stderr, "Failed to msync: %d\n", errno);
423	goto out_free_relocs;
424	}
425
426	out_free_relocs:
427	free(relocs);
428	munmap(elf, st.st_size);
429	out_close_fd:
430	close(fd);
431	out_ret:
432	return err;
433	}