target/linux/mvebu/patches-4.0/100-find_active_root.patch

   1 The WRT1900AC among other Linksys routers uses a dual-firmware layout.
   2 The bootloader passes the active rootfs in bootargs and also sets the
   3 rootfstype to jffs2 - which is clearly something we don't want.
   4
   5 Rename both root= and rootfstype= variables to avoid issues and also
   6 use the former to dynamically rename the active partition to "ubi".
   7
   8
   9 Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
  10
  11 --- a/arch/arm/boot/compressed/atags_to_fdt.c
  12 +++ b/arch/arm/boot/compressed/atags_to_fdt.c
  13 @@ -66,6 +66,18 @@ static uint32_t get_cell_size(const void
  14         return cell_size;
  15  }
  16
  17 +static void mangle_bootargs(void *fdt, const char *fdt_cmdline)
  18 +{
  19 +       char *rootdev;
  20 +       char *rootfs;
  21 +
  22 +       rootdev = strstr(fdt_cmdline, "root=/dev/mtdblock");
  23 +       strncpy(rootdev, "uboot_active_root=", 18);
  24 +
  25 +       rootfs = strstr(fdt_cmdline, "rootfstype");
  26 +       strncpy(rootfs, "origfstype", 10);
  27 +}
  28 +
  29  static void merge_fdt_bootargs(void *fdt, const char *fdt_cmdline)
  30  {
  31         char cmdline[COMMAND_LINE_SIZE];
  32 @@ -135,6 +147,9 @@ int atags_to_fdt(void *atag_list, void *
  33
  34         for_each_tag(atag, atag_list) {
  35                 if (atag->hdr.tag == ATAG_CMDLINE) {
  36 +                       /* Rename the original root= and rootfstype= options */
  37 +                       mangle_bootargs(fdt,
  38 +                                          atag->u.cmdline.cmdline);
  39                         /* Append the ATAGS command line to the device tree
  40                          * command line.
  41                          * NB: This means that if the same parameter is set in
  42 --- a/arch/arm/boot/compressed/string.c
  43 +++ b/arch/arm/boot/compressed/string.c
  44 @@ -111,6 +111,53 @@ char *strchr(const char *s, int c)
  45         return (char *)s;
  46  }
  47
  48 +/**
  49 + * strncpy - Copy a length-limited, %NUL-terminated string
  50 + * @dest: Where to copy the string to
  51 + * @src: Where to copy the string from
  52 + * @count: The maximum number of bytes to copy
  53 + *
  54 + * The result is not %NUL-terminated if the source exceeds
  55 + * @count bytes.
  56 + *
  57 + * In the case where the length of @src is less than  that  of
  58 + * count, the remainder of @dest will be padded with %NUL.
  59 + *
  60 + */
  61 +char *strncpy(char *dest, const char *src, size_t count)
  62 +{
  63 +       char *tmp = dest;
  64 +
  65 +       while (count) {
  66 +               if ((*tmp = *src) != 0)
  67 +                       src++;
  68 +               tmp++;
  69 +               count--;
  70 +       }
  71 +       return dest;
  72 +}
  73 +
  74 +/**
  75 + * strstr - Find the first substring in a %NUL terminated string
  76 + * @s1: The string to be searched
  77 + * @s2: The string to search for
  78 + */
  79 +char *strstr(const char *s1, const char *s2)
  80 +{
  81 +       size_t l1, l2;
  82 +
  83 +       l2 = strlen(s2);
  84 +       if (!l2)
  85 +               return (char *)s1;
  86 +       l1 = strlen(s1);
  87 +       while (l1 >= l2) {
  88 +               l1--;
  89 +               if (!memcmp(s1, s2, l2))
  90 +                       return (char *)s1;
  91 +               s1++;
  92 +       }
  93 +       return NULL;
  94 +}
  95  #undef memset
  96
  97  void *memset(void *s, int c, size_t count)
  98 --- a/drivers/mtd/ofpart.c
  99 +++ b/drivers/mtd/ofpart.c
 100 @@ -25,12 +25,15 @@ static bool node_has_compatible(struct d
 101         return of_get_property(pp, "compatible", NULL);
 102  }
 103
 104 +static int uboot_active_root;
 105 +
 106  static int parse_ofpart_partitions(struct mtd_info *master,
 107                                    struct mtd_partition **pparts,
 108                                    struct mtd_part_parser_data *data)
 109  {
 110         struct device_node *node;
 111         const char *partname;
 112 +       const char *owrtpart = "ubi";
 113         struct device_node *pp;
 114         int nr_parts, i;
 115
 116 @@ -78,9 +81,15 @@ static int parse_ofpart_partitions(struc
 117                 (*pparts)[i].offset = of_read_number(reg, a_cells);
 118                 (*pparts)[i].size = of_read_number(reg + a_cells, s_cells);
 119
 120 -               partname = of_get_property(pp, "label", &len);
 121 -               if (!partname)
 122 -                       partname = of_get_property(pp, "name", &len);
 123 +               if (uboot_active_root && (i == uboot_active_root)) {
 124 +                               partname = owrtpart;
 125 +               } else {
 126 +                       partname = of_get_property(pp, "label", &len);
 127 +
 128 +                       if (!partname)
 129 +                               partname = of_get_property(pp, "name", &len);
 130 +               }
 131 +
 132                 (*pparts)[i].name = partname;
 133
 134                 if (of_get_property(pp, "read-only", &len))
 135 @@ -178,6 +187,18 @@ static int __init ofpart_parser_init(voi
 136         return 0;
 137  }
 138
 139 +static int __init active_root(char *str)
 140 +{
 141 +       get_option(&str, &uboot_active_root);
 142 +
 143 +       if (!uboot_active_root)
 144 +               return 1;
 145 +
 146 +       return 1;
 147 +}
 148 +
 149 +__setup("uboot_active_root=", active_root);
 150 +
 151  static void __exit ofpart_parser_exit(void)
 152  {
 153         deregister_mtd_parser(&ofpart_parser);