--- /dev/null
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+/* #define DEBUG 1 */
+
+/*
+ * Fw Header Layout for Netgear / Sercomm devices
+ * */
+static const char *magic = "sErCoMm"; /* 7 */
+/* 7-11: version control/download control ? */
+unsigned char version[4] = {0x00, 0x01, 0x00, 0x00};
+char *hwID = ""; /* 11-43 , ASCII/HEX */
+char *hwVer = ""; /* 44-57 , ASCII/HEX */
+char *swVer = ""; /* 58-62 , ASCII/HEX */
+/* magic again. */
+
+#define HEADER_SIZE 71
+
+/* null bytes until 511 */
+u_int32_t checksum = 0xFF; /* checksum */
+/* 512 onwards -> ZIP containing rootfs with the same Header */
+
+
+/* appended on rootfs for the Header. */
+const int footer_size = 128;
+
+struct file_info {
+ char *file_name; /* name of the file */
+ char *file_data; /* data of the file in memory */
+ u_int32_t file_size; /* length of the file */
+};
+
+u_int8_t getCheckSum(char *data, int len)
+{
+
+ int32_t previous = 0;
+ u_int32_t new = 0;
+
+ for (u_int32_t i = 0; i < len; i++) {
+ new = (data[i] + previous) % 256;
+ previous = new | previous & -256;
+ }
+ return (u_int8_t) new;
+}
+
+void *bufferFile(struct file_info *finfo, int dontload)
+{
+ int fs = 0;
+ FILE *f = NULL;
+
+#ifdef DEBUG
+ printf("Opening file: %s\n", finfo->file_name);
+#endif
+ f = fopen(finfo->file_name, "rb");
+ if (f == NULL) {
+ perror("Error");
+ exit(1);
+ }
+
+ fseek(f, 0L, SEEK_END);
+ fs = ftell(f);
+ rewind(f);
+
+#ifdef DEBUG
+ printf("Filesize: %i .\n", fs);
+#endif
+
+ finfo->file_size = fs;
+
+ if (dontload) {
+ return 0;
+ }
+
+ char *data = malloc(fs);
+ finfo->file_data = data;
+
+ int read = fread(data, fs, 1, f);
+
+ if (read != 1) {
+ printf("Error reading file %s.", finfo->file_name);
+ exit(1);
+ }
+
+#ifdef DEBUG
+ printf("File: read successfully %i bytes.\n", read*fs);
+#endif
+ fclose(f);
+}
+
+void *writeFile(struct file_info *finfo)
+{
+
+#ifdef DEBUG
+ printf("Writing file: %s.\n", finfo->file_name);
+#endif
+
+ FILE *fout = fopen(finfo->file_name, "w");
+
+ if (!fwrite(finfo->file_data, finfo->file_size, 1, fout)) {
+ printf("Wanted to write, but something went wrong.\n");
+ fclose(fout);
+ exit(1);
+ }
+ fclose(fout);
+}
+
+void *rmFile(struct file_info *finfo)
+{
+ remove(finfo->file_name);
+ free(finfo->file_data);
+ finfo->file_size = 0;
+}
+
+void *usage(char *argv[])
+{
+ printf("Usage: %s <sysupgradefile> <kernel_offset> <HWID> <HWVER> <SWID>\n"
+ "All are positional arguments ... \n"
+ " sysupgradefile: File with the kernel uimage at 0\n"
+ " kernel_offset: Offset in Hex where the kernel is located\n"
+ " HWID: Hardware ID, ASCII\n"
+ " HWVER: Hardware Version, ASCII\n"
+ " SWID: Software Version, Hex\n"
+ " \n"
+ " ", argv[0]);
+}
+
+int main(int argc, char *argv[])
+{
+ printf("Building fw image for sercomm devices.\n");
+
+ if (argc == 2) {
+ struct file_info myfile = {argv[1], 0, 0};
+ bufferFile(&myfile, 0);
+ char chksum = getCheckSum(myfile.file_data, myfile.file_size);
+ printf("Checksum for File: %X.\n", chksum);
+ return;
+ }
+
+ if (argc != 6) {
+ usage(argv);
+ return 1;
+ }
+
+ /* Args */
+
+ struct file_info sysupgrade = {argv[1], 0, 0};
+ bufferFile(&sysupgrade, 0);
+
+ int kernel_offset = 0x90000; /* offset for the kernel inside the rootfs, default val */
+ sscanf(argv[2], "%X", &kernel_offset);
+#ifdef DEBUG
+ printf("Kernel_offset: at %X/%i bytes.\n", kernel_offset, kernel_offset);
+#endif
+ char *hwID = argv[3];
+ char *hwVer = argv[4];
+ u_int32_t swVer = 0;
+ sscanf(argv[5],"%4X",&swVer);
+ swVer = bswap_32(swVer);
+
+ char *rootfsname = malloc(2*strlen(sysupgrade.file_name) + 8);
+ sprintf(rootfsname, "%s.rootfs", sysupgrade.file_name);
+
+ char *zipfsname = malloc(2*strlen(rootfsname) + 5);
+ sprintf(zipfsname, "%s.zip", rootfsname);
+ /* / Args */
+
+#ifdef DEBUG
+ printf("Building header: %s %s %2X %s.\n", hwID , hwVer, swVer, magic);
+#endif
+ /* Construct the firmware header/magic */
+ struct file_info header = {0, 0, 0};
+ header.file_size = HEADER_SIZE;
+ header.file_data = malloc(HEADER_SIZE);
+ bzero(header.file_data, header.file_size);
+
+ char *tg = header.file_data;
+ strcpy(tg, magic);
+ memcpy(tg+7, version, 4*sizeof(char));
+ strcpy(tg+11, hwID);
+ strcpy(tg+45, hwVer);
+ memcpy(tg+55, &swVer,sizeof(u_int32_t));
+ strcpy(tg+63, magic);
+
+#ifdef DEBUG
+ printf("Header done, now creating rootfs.");
+#endif
+ /* Construct a rootfs */
+ struct file_info rootfs = {0, 0, 0};
+ rootfs.file_size = sysupgrade.file_size + kernel_offset + footer_size;
+ rootfs.file_data = malloc(rootfs.file_size);
+ bzero(rootfs.file_data, rootfs.file_size);
+ rootfs.file_name = rootfsname;
+
+ /* copy Owrt image to Kernel location */
+ memcpy(rootfs.file_data+kernel_offset, sysupgrade.file_data, sysupgrade.file_size);
+
+ /* 22 added to get away from sysup image, no other reason.
+ * updater searches for magic anyway */
+ tg = rootfs.file_data + kernel_offset + sysupgrade.file_size+22;
+
+ memcpy(tg, header.file_data, header.file_size);
+ writeFile(&rootfs);
+
+#ifdef DEBUG
+ printf("Preparing to zip.\n");
+#endif
+ /* now that we got the rootfs, repeat the whole thing again(sorta):
+ * 1. zip the rootfs */
+ char *zipper = malloc(5 + 2*strlen(rootfs.file_name) + 4);
+ sprintf(zipper, "%s %s %s", "zip ", zipfsname, rootfs.file_name);
+ int ret = system(zipper);
+
+ /* clear rootfs file */
+ rmFile(&rootfs);
+
+ /* and load zipped fs */
+ struct file_info zippedfs = {zipfsname, 0, 0};
+ bufferFile(&zippedfs, 0);
+
+#ifdef DEBUG
+ printf("Creating Image.\n");
+#endif
+
+ /* 2. create new file 512+rootfs size */
+ struct file_info image = {argv[1], 0, 0};
+ image.file_data = malloc(zippedfs.file_size + 512);
+ image.file_size = zippedfs.file_size + 512;
+
+ /* 3. copy zipfile at loc 512 */
+ memcpy(image.file_data+512, zippedfs.file_data, zippedfs.file_size);
+ rmFile(&zippedfs);
+
+ /* 4. add header to file */
+ memcpy(image.file_data, header.file_data, header.file_size);
+
+ /* 5. do a checksum run, and compute checksum */
+ char chksum = getCheckSum(image.file_data, image.file_size);
+#ifdef DEBUG
+ printf("Checksum for Image: %X.\n", chksum);
+#endif
+
+ /* 6. write the checksum invert into byte 511 to bring it to 0 */
+ chksum = (chksum ^ 0xFF) + 1;
+ memcpy(image.file_data+511, &chksum, 1);
+
+ chksum = getCheckSum(image.file_data, image.file_size);
+#ifdef DEBUG
+ printf("Checksum for after fix: %X.\n", chksum);
+#endif
+ /* 7. pray that the updater will accept the file */
+ writeFile(&image);
+ return 0;
+}