mtd: add logic for TP-Link ramips recovery magic

[openwrt/staging/wigyori.git] / package / system / mtd / src / tpl_ramips_recoveryflag.c

diff --git a/package/system/mtd/src/tpl_ramips_recoveryflag.c b/package/system/mtd/src/tpl_ramips_recoveryflag.c
new file mode 100644 (file)
index 0000000..3711e01
--- /dev/null
+++ b/package/system/mtd/src/tpl_ramips_recoveryflag.c
@@ -0,0 +1,94 @@
+/*
+ * TP-Link recovery flag set and unset code for ramips target
+ *
+ * Copyright (C) 2018 David Bauer <mail@david-bauer.net>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License v2
+ * as published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <errno.h>
+#include <stdint.h>
+
+#include <mtd/mtd-user.h>
+#include <sys/ioctl.h>
+
+#include "mtd.h"
+
+
+#define TPL_RECOVER_MAGIC      0x89abcdef
+#define TPL_NO_RECOVER_MAGIC   0x00000000
+
+
+struct uboot_args {
+       uint32_t magic;
+};
+
+int mtd_tpl_recoverflag_write(const char *mtd, const bool recovery_active)
+{
+       struct erase_info_user erase_info;
+       struct uboot_args *args;
+       uint32_t magic;
+       int ret = 0;
+       int fd;
+
+       args = malloc(erasesize);
+       if (!args) {
+               fprintf(stderr, "Could not allocate memory!\n");
+               return -1;
+       }
+
+       fd = mtd_check_open(mtd);
+       if (fd < 0) {
+               fprintf(stderr, "Could not open mtd device: %s\n", mtd);
+               ret = -1;
+               goto out;
+       }
+
+       /* read first block (containing the magic) */
+       pread(fd, args, erasesize, 0);
+
+       /* set magic to desired value */
+       magic = TPL_RECOVER_MAGIC;
+       if (!recovery_active)
+               magic = TPL_NO_RECOVER_MAGIC;
+
+       /* no need to write when magic is already set correctly */
+       if (magic == args->magic)
+               goto out;
+
+       /* erase first block (containing the magic) */
+       erase_info.start = 0;
+       erase_info.length = erasesize;
+
+       ret = ioctl(fd, MEMERASE, &erase_info);
+       if (ret < 0) {
+               fprintf(stderr, "failed to erase block: %i\n", ret);
+               goto out;
+       }
+
+       /* write magic to flash */
+       args->magic = magic;
+
+       ret = pwrite(fd, args, erasesize, 0);
+       if (ret < 0)
+               fprintf(stderr, "failed to write: %i\n", ret);
+
+       sync();
+out:
+       free(args);
+       close(fd);
+
+       return ret;
+}