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-rw-r--r--mkubootenv/mkubootenv.c330
1 files changed, 330 insertions, 0 deletions
diff --git a/mkubootenv/mkubootenv.c b/mkubootenv/mkubootenv.c
new file mode 100644
index 0000000..8e49cbb
--- /dev/null
+++ b/mkubootenv/mkubootenv.c
@@ -0,0 +1,330 @@
+/*
+ * mkubootenv.c
+ *
+ * Create a U-Boot environment image suitable for flashing.
+ *
+ * The input is a text file containing environment variable
+ * definitions in the format "name=value", separeated by newlines.
+ *
+ * The "environment" (output) is stored as a list of '\0' terminated
+ * "name=value" strings. The end of the list is marked by a double '\0'.
+ *
+ * The environment is preceeded by a 32 bit CRC over the data part.
+ *
+ * Copyright (c) 2009, Zurich University of Applied Sciences
+ * Copyright (c) 2009, Tobias Klauser <klto@zhaw.ch>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+
+#include "crc32.h"
+
+#undef DEBUG
+
+#define CMD_NAME "mkubootenv"
+
+#define CRC32_SIZE sizeof(uint32_t)
+/* minimum trailing null bytes */
+#define TRAILER_SIZE 2
+
+#define err(fmt, args...) fprintf(stderr, "%s: Error: " fmt, CMD_NAME, ##args)
+#define warn(fmt, args...) fprintf(stderr, "%s: Warning: " fmt, CMD_NAME, ##args)
+#ifdef DEBUG
+# define dbg(fmt, args...) fprintf(stdout, fmt, ##args)
+#else
+# define dbg(fmt, args...)
+#endif
+
+/* file "object" */
+struct file {
+ const char *name;
+ int fd;
+ uint8_t *ptr;
+ size_t size;
+};
+
+static void usage_and_exit(int status) __attribute__((noreturn));
+
+static inline void uboot_env_init_file(struct file *f)
+{
+ memset(f, 0, sizeof(struct file));
+ f->ptr = MAP_FAILED;
+}
+
+static int uboot_env_prepare_source(struct file *s)
+{
+ struct stat sbuf;
+
+ s->fd = open(s->name, O_RDONLY);
+ if (s->fd < 0) {
+ err("Can't open source file '%s': %s\n", s->name,
+ strerror(errno));
+ return EXIT_FAILURE;
+ }
+
+ if (fstat(s->fd, &sbuf) < 0) {
+ err("Can't stat source file '%s': %s\n", s->name,
+ strerror(errno));
+ close(s->fd);
+ return -1;
+ }
+
+ s->ptr = mmap(NULL, sbuf.st_size, PROT_READ, MAP_SHARED, s->fd, 0);
+ if (s->ptr == MAP_FAILED) {
+ err("Can't mmap source image file '%s': %s\n", s->name,
+ strerror(errno));
+ close(s->fd);
+ return -1;
+ }
+
+ s->size = sbuf.st_size;
+
+ return 0;
+}
+
+static int uboot_env_prepare_target(struct file *t)
+{
+ t->fd = open(t->name, O_RDWR|O_CREAT|O_TRUNC, 0666);
+ if (t->fd < 0) {
+ err("Can't open target image file '%s': %s\n", t->name,
+ strerror(errno));
+ return -1;
+ }
+
+ /*
+ * seek to the end of the target file to write a byte, so we have the
+ * whole target image size mapped for writing
+ */
+ if (lseek(t->fd, t->size - 1, SEEK_SET) < 0) {
+ err("Can't seek in target image file '%s': %s\n", t->name,
+ strerror(errno));
+ close(t->fd);
+ return -1;
+ }
+
+ if (write(t->fd, "", 1) < 0) {
+ err("Can't write to target image file '%s': %s\n", t->name,
+ strerror(errno));
+ close(t->fd);
+ return -1;
+ }
+
+ t->ptr = mmap(NULL, t->size, PROT_READ|PROT_WRITE, MAP_SHARED, t->fd, 0);
+ if (t->ptr == MAP_FAILED) {
+ err("Can't mmap target image file '%s': %s\n", t->name,
+ strerror(errno));
+ close(t->fd);
+ return -1;
+ }
+
+ return 0;
+}
+
+static void uboot_env_cleanup_file(struct file *f)
+{
+ if (f->ptr != MAP_FAILED)
+ munmap(f->ptr, f->size);
+ if (f->fd > 0)
+ close(f->fd);
+}
+
+static void uboot_env_to_img(struct file *s, struct file *t)
+{
+ uint8_t *p, *q, *end;
+ uint32_t *crc;
+
+ dbg("source file (env): %s\n", s->name);
+ dbg("target image file (bin): %s\n", t->name);
+ dbg("target size: %zd\n", t->size);
+
+ /* CRC32 placeholder, will be filled later */
+ end = t->ptr + CRC32_SIZE;
+ for (p = t->ptr; p < end; p++)
+ *p = 0;
+
+ /* copy the source file, replacing \n by \0 */
+ end = s->ptr + s->size;
+ for (q = s->ptr; q < end; q++, p++)
+ *p = (*q == '\n') ? '\0' : *q;
+
+ /* trailer */
+ end = s->ptr + t->size;
+ for (q = s->ptr + s->size; q < end; q++)
+ *p = 0;
+
+ /* now for the real CRC32 */
+ crc = (uint32_t *) t->ptr;
+ *crc = crc32(0, t->ptr + CRC32_SIZE, t->size - CRC32_SIZE);
+}
+
+static void uboot_img_to_env(struct file *s, struct file *t)
+{
+ uint8_t *p, *q, *end;
+ uint32_t *crc;
+
+ dbg("source file (bin): %s\n", s->name);
+ dbg("target image file (env): %s\n", t->name);
+ dbg("target size: %zd\n", t->size);
+
+ /* check CRC */
+ crc = (uint32_t *) s->ptr;
+ if (*crc != crc32(0, s->ptr + CRC32_SIZE, s->size - CRC32_SIZE))
+ warn("source image with bad CRC\n");
+
+ p = t->ptr;
+ end = s->ptr + CRC32_SIZE + t->size;
+ for (q = s->ptr + CRC32_SIZE; q < end; p++, q++)
+ *p = (*q == '\0') ? '\n' : *q;
+}
+
+static void usage_and_exit(int status)
+{
+ printf("usage: mkubootenv [-s <size>] <source file> <target file>\n"
+ " -s <size> set size of the target image file to <size> bytes. If <size> is\n"
+ " bigger than the source file, the target image gets padded with null\n"
+ " bytes. If <size> is smaller than the source file, an error is emitted.\n"
+ " -r reverse operation: get plaintext env file (target) from binary image\n"
+ " file (source)\n");
+ exit(status);
+}
+
+int main(int argc, char **argv)
+{
+ int i;
+ int status = EXIT_FAILURE;
+ ssize_t img_size = -1;
+ bool reverse = false;
+ struct file s, t; /* source and target file */
+
+ if (argc < 2)
+ usage_and_exit(EXIT_FAILURE);
+
+ /* parse commandline options */
+ for (i = 1; (i + 1 < argc) && (argv[i][0] == '-'); i++) {
+ switch (argv[i][1]) {
+ case 's': {
+ char *opt = argv[++i];
+
+ if (strlen(opt) > 2 && opt[0] == '0' &&
+ (opt[1] == 'x' || opt[1] == 'X')) {
+ img_size = strtol(opt, NULL, 16);
+ } else {
+ img_size = strtol(opt, NULL, 10);
+
+ if (img_size <= 0) {
+ err("Invalid target image size: %zd. Must be greater than 0.\n", img_size);
+ exit(EXIT_FAILURE);
+ }
+ }
+ break;
+ }
+ case 'r':
+ reverse = true;
+ break;
+ case 'h':
+ status = EXIT_SUCCESS;
+ /* fall through */
+ default:
+ usage_and_exit(status);
+ break;
+ }
+ }
+
+ /* we expect two filenames */
+ if (i + 2 > argc)
+ usage_and_exit(EXIT_FAILURE);
+
+ if (reverse && img_size >= 0)
+ warn("Image size specified in reverse mode will be ignored\n");
+
+ uboot_env_init_file(&s);
+ uboot_env_init_file(&t);
+ s.name = argv[i];
+ t.name = argv[i+1];
+
+ if (uboot_env_prepare_source(&s))
+ exit(EXIT_FAILURE);
+
+ if (!reverse) {
+ ssize_t min_img_size = CRC32_SIZE + s.size + TRAILER_SIZE;
+
+ /* TODO: Check source file format:
+ * var=value\n
+ */
+
+ /*
+ * check whether the size hasn't been set or whether the source file +
+ * CRC + trailer fits into the specified size.
+ */
+ if (img_size < 0)
+ img_size = min_img_size;
+ else if (img_size < min_img_size) {
+ err("Specified size (%zd) is too small for the source file to "
+ "fit into. Must be at least %zd bytes.\n",
+ img_size, min_img_size);
+ goto cleanup_source;
+ }
+
+ t.size = img_size;
+ if (uboot_env_prepare_target(&t))
+ goto cleanup_source;
+
+ uboot_env_to_img(&s, &t);
+ } else {
+ uint8_t *p;
+ uint8_t *end;
+ bool found_data_end = false;
+
+ /* get the length of the data part */
+ end = s.ptr + CRC32_SIZE + s.size;
+ for (p = s.ptr + CRC32_SIZE; (p < end - 1) && (!found_data_end); p++) {
+ /* two null bytes mark the end of the data section */
+ if (*p == '\0' && *(p + 1) == '\0')
+ found_data_end = true;
+ }
+
+ if (!found_data_end)
+ warn("No end of list delimiter found in source file\n");
+
+ /* calculate the plain text file size */
+ t.size = p - (s.ptr + CRC32_SIZE);
+ if (uboot_env_prepare_target(&t))
+ goto cleanup_source;
+
+ uboot_img_to_env(&s, &t);
+ }
+
+ status = EXIT_SUCCESS;
+
+ uboot_env_cleanup_file(&t);
+cleanup_source:
+ uboot_env_cleanup_file(&s);
+
+ exit(status);
+}
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2024-06-02 12:15:58 +0000