firmware-utils: add JBOOT bootloader image support

Tested on D-Link DWR-116.
Based on mktplinkfw.

Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>

tools/firmware-utils/src/mkdlinkfw-lib.c

@@ -0,0 +1,172 @@
+/*
+ * mkdlinkfw
+ *
+ * Copyright (C) 2018 Paweł Dembicki <paweldembicki@gmail.com>
+ *
+ * This tool is based on mktplinkfw.
+ * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
+ * Copyright (C) 2008,2009 Wang Jian <lark@linux.net.cn>
+ *
+ * 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.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>		/* for unlink() */
+#include <libgen.h>
+#include <getopt.h>		/* for getopt() */
+#include <stdarg.h>
+#include <stdbool.h>
+#include <endian.h>
+#include <errno.h>
+#include <time.h>
+#include <sys/stat.h>
+#include <zlib.h>		/*for crc32 */
+
+#include "mkdlinkfw-lib.h"
+
+extern char *progname;
+
+static unsigned char jffs2_eof_mark[4] = { 0xde, 0xad, 0xc0, 0xde };
+
+uint32_t jboot_timestamp(void)
+{
+	time_t rawtime;
+	time(&rawtime);
+	return (((uint32_t) rawtime) - TIMESTAMP_MAGIC) >> 2;
+}
+
+uint16_t jboot_checksum(uint16_t start_val, uint16_t *data, int size)
+{
+	uint32_t counter = start_val;
+	uint16_t *ptr = data;
+
+	while (size > 1) {
+		counter += *ptr;
+		++ptr;
+		while (counter >> 16)
+			counter = (uint16_t) counter + (counter >> 16);
+		size -= 2;
+	}
+	if (size > 0) {
+		counter += *(uint8_t *) ptr;
+		counter -= 0xFF;
+	}
+	while (counter >> 16)
+		counter = (uint16_t) counter + (counter >> 16);
+	return counter;
+}
+
+int get_file_stat(struct file_info *fdata)
+{
+	struct stat st;
+	int res;
+
+	if (fdata->file_name == NULL)
+		return 0;
+
+	res = stat(fdata->file_name, &st);
+	if (res) {
+		ERRS("stat failed on %s", fdata->file_name);
+		return res;
+	}
+
+	fdata->file_size = st.st_size;
+	return 0;
+}
+
+int read_to_buf(const struct file_info *fdata, char *buf)
+{
+	FILE *f;
+	int ret = EXIT_FAILURE;
+
+	f = fopen(fdata->file_name, "r");
+	if (f == NULL) {
+		ERRS("could not open \"%s\" for reading", fdata->file_name);
+		goto out;
+	}
+
+	errno = 0;
+	fread(buf, fdata->file_size, 1, f);
+	if (errno != 0) {
+		ERRS("unable to read from file \"%s\"", fdata->file_name);
+		goto out_close;
+	}
+
+	ret = EXIT_SUCCESS;
+
+ out_close:
+	fclose(f);
+ out:
+	return ret;
+}
+
+int pad_jffs2(char *buf, int currlen, int maxlen)
+{
+	int len;
+	uint32_t pad_mask;
+
+	len = currlen;
+	pad_mask = (4 * 1024) | (64 * 1024);	/* EOF at 4KB and at 64KB */
+	while ((len < maxlen) && (pad_mask != 0)) {
+		uint32_t mask;
+		int i;
+
+		for (i = 10; i < 32; i++) {
+			mask = 1 << i;
+			if (pad_mask & mask)
+				break;
+		}
+
+		len = ALIGN(len, mask);
+
+		for (i = 10; i < 32; i++) {
+			mask = 1 << i;
+			if ((len & (mask - 1)) == 0)
+				pad_mask &= ~mask;
+		}
+
+		for (i = 0; i < sizeof(jffs2_eof_mark); i++)
+			buf[len + i] = jffs2_eof_mark[i];
+
+		len += sizeof(jffs2_eof_mark);
+	}
+
+	return len;
+}
+
+int write_fw(const char *ofname, const char *data, int len)
+{
+	FILE *f;
+	int ret = EXIT_FAILURE;
+
+	f = fopen(ofname, "w");
+	if (f == NULL) {
+		ERRS("could not open \"%s\" for writing", ofname);
+		goto out;
+	}
+
+	errno = 0;
+	fwrite(data, len, 1, f);
+	if (errno) {
+		ERRS("unable to write output file");
+		goto out_flush;
+	}
+
+	DBG("firmware file \"%s\" completed", ofname);
+
+	ret = EXIT_SUCCESS;
+
+ out_flush:
+	fflush(f);
+	fclose(f);
+	if (ret != EXIT_SUCCESS)
+		unlink(ofname);
+ out:
+	return ret;
+}