Initial import of U-Boot environment image creator

1 files changed, 224 insertions, 0 deletions

diff --git a/mkubootenv.c b/mkubootenv.c
new file mode 100644
index 0000000..f2b94ec
--- /dev/null
+++ b/mkubootenv.c
@@ -0,0 +1,224 @@
+/*
+ * Copyright (c) 2009, Zurich University of Applied Science
+ * 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"
+
+#define DEBUG
+
+#define CMD_NAME		"mkenv"
+#define DEFAULT_IMG_TYPE	"binary"
+
+#define CRC32_SIZE		sizeof(uint32_t)
+/* minimum trailing null bytes */
+#define TRAILER_SIZE		sizeof(uint16_t)
+
+#define err(fmt, args...)	fprintf(stderr, "%s: Error: " fmt, CMD_NAME, ##args)
+#ifdef DEBUG
+# define dbg(fmt, args...)	fprintf(stdout, fmt, ##args)
+#else
+# define dbg(fmt, args...)
+#endif
+
+/* file "object" */
+struct file {
+	char *name;
+	int fd;
+	uint8_t *ptr;
+	struct stat sbuf;
+};
+
+static void usage_and_exit(int status) __attribute__((noreturn));
+
+static void usage_and_exit(int status)
+{
+	printf("usage: mkenv [-t <type>] [-s <size>] <source file> <target image 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"
+	       "  -t <type>  set type of the target image, where <type> is one of:\n"
+	       "             - binary (default if -t is not specified)\n"
+	       "             - srec\n"
+	       "  -r         reverse operation: get source file from target image file\n");
+	exit(status);
+}
+
+int main(int argc, char **argv)
+{
+	int i;
+	int status = EXIT_FAILURE;
+	struct file s, t;	/* source and target file */
+	ssize_t img_size = -1;
+	ssize_t min_img_size;
+	char img_type[7];
+	bool reverse = false;
+	uint8_t *p, *q;
+	uint32_t *crc;
+
+	if (argc < 2)
+		usage_and_exit(EXIT_FAILURE);
+
+	snprintf(img_type, sizeof(img_type), "%s", DEFAULT_IMG_TYPE);
+
+	/* parse commandline options */
+	for (i = 1; (i + 1 < argc) && (argv[i][0] == '-'); i++) {
+		switch (argv[i][1]) {
+		case 's':
+			img_size = strtol(argv[++i], NULL, 10);
+			break;
+		case 't':
+			snprintf(img_type, sizeof(img_type), "%s", argv[++i]);
+			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);
+
+	s.name = argv[i];
+	t.name = argv[++i];
+
+	s.fd = open(s.name, O_RDONLY);
+	if (s.fd < 0) {
+		err("Can't open source file '%s': %s\n", s.name,
+				strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+
+	if (fstat(s.fd, &s.sbuf) < 0) {
+		err("Can't stat source file '%s': %s\n", s.name,
+				strerror(errno));
+		goto err_out_close_s;
+	}
+
+	s.ptr = mmap(NULL, s.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));
+		goto err_out_close_s;
+	}
+
+	/* 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.
+	 */
+	min_img_size = CRC32_SIZE + s.sbuf.st_size + TRAILER_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 err_out_munmap_s;
+	}
+
+	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));
+		goto err_out_munmap_s;
+	}
+
+	/* seek to the end of the target file to write a byte */
+	if (lseek(t.fd, img_size - 1, SEEK_SET) < 0) {
+		err("Can't seek in target image file '%s': %s\n", t.name,
+				strerror(errno));
+		goto err_out_close_t;
+	}
+
+	if (write(t.fd, "", 1) < 0) {
+		err("Can't write to target image file '%s': %s\n", t.name,
+				strerror(errno));
+		goto err_out_close_t;
+	}
+
+	t.ptr = mmap(NULL, img_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));
+		goto err_out_close_t;
+	}
+
+	printf("source file:       %s\n", s.name);
+	printf("target image file: %s\n", t.name);
+	printf("size:              %zd\n", img_size);
+	printf("type:              %s\n", img_type);
+
+	/* CRC32 placeholder, will be filled later */
+	dbg("writing crc...\n");
+	for (p = t.ptr; p < t.ptr + CRC32_SIZE; p++)
+		*p = 0;
+
+	/* copy the source file, replacing \n by \0 */
+	dbg("writing data...\n");
+	for (q = s.ptr; q < s.ptr + s.sbuf.st_size; q++, p++) {
+		uint8_t c = (*q == '\n') ? '\0' : *q;
+
+		*p = c;
+	}
+
+	/* trailer */
+	dbg("writing trailer...\n");
+	for (q = s.ptr + s.sbuf.st_size; q < s.ptr + img_size; q++)
+		*p = 0;
+
+	/* now for the real CRC32 */
+	dbg("calculating crc...\n");
+	crc = (uint32_t *) t.ptr;
+	*crc = crc32(0, t.ptr + CRC32_SIZE, img_size - CRC32_SIZE);
+	dbg("crc: %08x\n", *crc);
+
+	status = EXIT_SUCCESS;
+
+	munmap(t.ptr, img_size);
+err_out_close_t:
+	close(t.fd);
+err_out_munmap_s:
+	munmap(s.ptr, s.sbuf.st_size);
+err_out_close_s:
+	close(s.fd);
+
+	exit(status);
+}