target/linux/ipq806x/patches-6.1/0067-generic-Mangle-bootloader-s-kernel-arguments.patch

   1 From 71270226b14733a4b1f2cde58ea9265caa50b38d Mon Sep 17 00:00:00 2001
   2 From: Adrian Panella <ianchi74@outlook.com>
   3 Date: Thu, 9 Mar 2017 09:37:17 +0100
   4 Subject: [PATCH 67/69] generic: Mangle bootloader's kernel arguments
   5
   6 The command-line arguments provided by the boot loader will be
   7 appended to a new device tree property: bootloader-args.
   8 If there is a property "append-rootblock" in DT under /chosen
   9 and a root= option in bootloaders command line it will be parsed
  10 and added to DT bootargs with the form: <append-rootblock>XX.
  11 Only command line ATAG will be processed, the rest of the ATAGs
  12 sent by bootloader will be ignored.
  13 This is usefull in dual boot systems, to get the current root partition
  14 without afecting the rest of the system.
  15
  16 Signed-off-by: Adrian Panella <ianchi74@outlook.com>
  17 ---
  18  arch/arm/Kconfig                        | 11 +++++
  19  arch/arm/boot/compressed/atags_to_fdt.c | 72 ++++++++++++++++++++++++++++++++-
  20  init/main.c                             | 16 ++++++++
  21  3 files changed, 98 insertions(+), 1 deletion(-)
  22
  23 --- a/arch/arm/Kconfig
  24 +++ b/arch/arm/Kconfig
  25 @@ -1588,6 +1588,17 @@ config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEN
  26           The command-line arguments provided by the boot loader will be
  27           appended to the the device tree bootargs property.
  28
  29 +config ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
  30 +       bool "Append rootblock parsing bootloader's kernel arguments"
  31 +       help
  32 +         The command-line arguments provided by the boot loader will be
  33 +         appended to a new device tree property: bootloader-args.
  34 +         If there is a property "append-rootblock" in DT under /chosen
  35 +         and a root= option in bootloaders command line it will be parsed
  36 +         and added to DT bootargs with the form: <append-rootblock>XX.
  37 +         Only command line ATAG will be processed, the rest of the ATAGs
  38 +         sent by bootloader will be ignored.
  39 +
  40  endchoice
  41
  42  config CMDLINE
  43 --- a/arch/arm/boot/compressed/atags_to_fdt.c
  44 +++ b/arch/arm/boot/compressed/atags_to_fdt.c
  45 @@ -5,6 +5,8 @@
  46
  47  #if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND)
  48  #define do_extend_cmdline 1
  49 +#elif defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
  50 +#define do_extend_cmdline 1
  51  #else
  52  #define do_extend_cmdline 0
  53  #endif
  54 @@ -20,6 +22,7 @@ static int node_offset(void *fdt, const
  55         return offset;
  56  }
  57
  58 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
  59  static int setprop(void *fdt, const char *node_path, const char *property,
  60                    void *val_array, int size)
  61  {
  62 @@ -28,6 +31,7 @@ static int setprop(void *fdt, const char
  63                 return offset;
  64         return fdt_setprop(fdt, offset, property, val_array, size);
  65  }
  66 +#endif
  67
  68  static int setprop_string(void *fdt, const char *node_path,
  69                           const char *property, const char *string)
  70 @@ -38,6 +42,7 @@ static int setprop_string(void *fdt, con
  71         return fdt_setprop_string(fdt, offset, property, string);
  72  }
  73
  74 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
  75  static int setprop_cell(void *fdt, const char *node_path,
  76                         const char *property, uint32_t val)
  77  {
  78 @@ -46,6 +51,7 @@ static int setprop_cell(void *fdt, const
  79                 return offset;
  80         return fdt_setprop_cell(fdt, offset, property, val);
  81  }
  82 +#endif
  83
  84  static const void *getprop(const void *fdt, const char *node_path,
  85                            const char *property, int *len)
  86 @@ -58,6 +64,7 @@ static const void *getprop(const void *f
  87         return fdt_getprop(fdt, offset, property, len);
  88  }
  89
  90 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
  91  static uint32_t get_cell_size(const void *fdt)
  92  {
  93         int len;
  94 @@ -68,6 +75,81 @@ static uint32_t get_cell_size(const void
  95                 cell_size = fdt32_to_cpu(*size_len);
  96         return cell_size;
  97  }
  98 +#endif
  99 +
 100 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
 101 +/**
 102 + * taken from arch/x86/boot/string.c
 103 + * local_strstr - Find the first substring in a %NUL terminated string
 104 + * @s1: The string to be searched
 105 + * @s2: The string to search for
 106 + */
 107 +static char *local_strstr(const char *s1, const char *s2)
 108 +{
 109 +       size_t l1, l2;
 110 +
 111 +       l2 = strlen(s2);
 112 +       if (!l2)
 113 +               return (char *)s1;
 114 +       l1 = strlen(s1);
 115 +       while (l1 >= l2) {
 116 +               l1--;
 117 +               if (!memcmp(s1, s2, l2))
 118 +                       return (char *)s1;
 119 +               s1++;
 120 +       }
 121 +       return NULL;
 122 +}
 123 +
 124 +static char *append_rootblock(char *dest, const char *str, int len, void *fdt)
 125 +{
 126 +       char *ptr, *end, *tmp;
 127 +       const char *root="root=";
 128 +       const char *find_rootblock;
 129 +       int i, l;
 130 +       const char *rootblock;
 131 +
 132 +       find_rootblock = getprop(fdt, "/chosen", "find-rootblock", &l);
 133 +       if (!find_rootblock)
 134 +               find_rootblock = root;
 135 +
 136 +       //ARM doesn't have __HAVE_ARCH_STRSTR, so it was copied from x86
 137 +       ptr = local_strstr(str, find_rootblock);
 138 +
 139 +       if(!ptr)
 140 +               return dest;
 141 +
 142 +       end = strchr(ptr, ' ');
 143 +       end = end ? (end - 1) : (strchr(ptr, 0) - 1);
 144 +
 145 +       // Some boards ubi.mtd=XX,ZZZZ, so let's check for '," too.
 146 +       tmp = strchr(ptr, ',');
 147 +
 148 +       if(tmp)
 149 +               end = end < tmp ? end : tmp - 1;
 150 +
 151 +       //find partition number (assumes format root=/dev/mtdXX | /dev/mtdblockXX | yy:XX | ubi.mtd=XX,ZZZZ )
 152 +       for( i = 0; end >= ptr && *end >= '0' && *end <= '9'; end--, i++);
 153 +       ptr = end + 1;
 154 +
 155 +       /* if append-rootblock property is set use it to append to command line */
 156 +       rootblock = getprop(fdt, "/chosen", "append-rootblock", &l);
 157 +       if(rootblock != NULL) {
 158 +               if(*dest != ' ') {
 159 +                       *dest = ' ';
 160 +                       dest++;
 161 +                       len++;
 162 +               }
 163 +               if (len + l + i <= COMMAND_LINE_SIZE) {
 164 +                       memcpy(dest, rootblock, l);
 165 +                       dest += l - 1;
 166 +                       memcpy(dest, ptr, i);
 167 +                       dest += i;
 168 +               }
 169 +       }
 170 +       return dest;
 171 +}
 172 +#endif
 173
 174  static void merge_fdt_bootargs(void *fdt, const char *fdt_cmdline)
 175  {
 176 @@ -88,18 +170,28 @@ static void merge_fdt_bootargs(void *fdt
 177
 178         /* and append the ATAG_CMDLINE */
 179         if (fdt_cmdline) {
 180 +
 181 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
 182 +               //save original bootloader args
 183 +               //and append ubi.mtd with root partition number to current cmdline
 184 +               setprop_string(fdt, "/chosen", "bootloader-args", fdt_cmdline);
 185 +               ptr = append_rootblock(ptr, fdt_cmdline, len, fdt);
 186 +
 187 +#else
 188                 len = strlen(fdt_cmdline);
 189                 if (ptr - cmdline + len + 2 < COMMAND_LINE_SIZE) {
 190                         *ptr++ = ' ';
 191                         memcpy(ptr, fdt_cmdline, len);
 192                         ptr += len;
 193                 }
 194 +#endif
 195         }
 196         *ptr = '\0';
 197
 198         setprop_string(fdt, "/chosen", "bootargs", cmdline);
 199  }
 200
 201 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
 202  static void hex_str(char *out, uint32_t value)
 203  {
 204         uint32_t digit;
 205 @@ -117,6 +209,7 @@ static void hex_str(char *out, uint32_t
 206         }
 207         *out = '\0';
 208  }
 209 +#endif
 210
 211  /*
 212   * Convert and fold provided ATAGs into the provided FDT.
 213 @@ -131,9 +224,11 @@ int atags_to_fdt(void *atag_list, void *
 214         struct tag *atag = atag_list;
 215         /* In the case of 64 bits memory size, need to reserve 2 cells for
 216          * address and size for each bank */
 217 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
 218         __be32 mem_reg_property[2 * 2 * NR_BANKS];
 219 -       int memcount = 0;
 220 -       int ret, memsize;
 221 +       int memsize, memcount = 0;
 222 +#endif
 223 +       int ret;
 224
 225         /* make sure we've got an aligned pointer */
 226         if ((u32)atag_list & 0x3)
 227 @@ -168,7 +263,9 @@ int atags_to_fdt(void *atag_list, void *
 228                         else
 229                                 setprop_string(fdt, "/chosen", "bootargs",
 230                                                atag->u.cmdline.cmdline);
 231 -               } else if (atag->hdr.tag == ATAG_MEM) {
 232 +               }
 233 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
 234 +               else if (atag->hdr.tag == ATAG_MEM) {
 235                         if (memcount >= sizeof(mem_reg_property)/4)
 236                                 continue;
 237                         if (!atag->u.mem.size)
 238 @@ -212,6 +309,10 @@ int atags_to_fdt(void *atag_list, void *
 239                 setprop(fdt, "/memory", "reg", mem_reg_property,
 240                         4 * memcount * memsize);
 241         }
 242 +#else
 243 +
 244 +       }
 245 +#endif
 246
 247         return fdt_pack(fdt);
 248  }
 249 --- a/init/main.c
 250 +++ b/init/main.c
 251 @@ -112,6 +112,10 @@
 252
 253  #include <kunit/test.h>
 254
 255 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
 256 +#include <linux/of.h>
 257 +#endif
 258 +
 259  static int kernel_init(void *);
 260
 261  extern void init_IRQ(void);
 262 @@ -991,6 +995,18 @@ asmlinkage __visible void __init __no_sa
 263         pr_notice("Kernel command line: %s\n", saved_command_line);
 264         /* parameters may set static keys */
 265         jump_label_init();
 266 +
 267 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
 268 +       //Show bootloader's original command line for reference
 269 +       if(of_chosen) {
 270 +               const char *prop = of_get_property(of_chosen, "bootloader-args", NULL);
 271 +               if(prop)
 272 +                       pr_notice("Bootloader command line (ignored): %s\n", prop);
 273 +               else
 274 +                       pr_notice("Bootloader command line not present\n");
 275 +       }
 276 +#endif
 277 +
 278         parse_early_param();
 279         after_dashes = parse_args("Booting kernel",
 280                                   static_command_line, __start___param,