target/linux/oxnas/patches-5.15/996-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 @@ -1728,6 +1728,17 @@ 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 @@ -69,6 +76,61 @@ static uint32_t get_cell_size(const void
  95         return cell_size;
  96  }
  97
  98 +#endif
  99 +
 100 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
 101 +
 102 +static char *append_rootblock(char *dest, const char *str, int len, void *fdt)
 103 +{
 104 +       const char *ptr, *end;
 105 +       const char *root="root=";
 106 +       int i, l;
 107 +       const char *rootblock;
 108 +
 109 +       //ARM doesn't have __HAVE_ARCH_STRSTR, so search manually
 110 +       ptr = str - 1;
 111 +
 112 +       do {
 113 +               //first find an 'r' at the begining or after a space
 114 +               do {
 115 +                       ptr++;
 116 +                       ptr = strchr(ptr, 'r');
 117 +                       if(!ptr) return dest;
 118 +
 119 +               } while (ptr != str && *(ptr-1) != ' ');
 120 +
 121 +               //then check for the rest
 122 +               for(i = 1; i <= 4; i++)
 123 +                       if(*(ptr+i) != *(root+i)) break;
 124 +
 125 +       } while (i != 5);
 126 +
 127 +       end = strchr(ptr, ' ');
 128 +       end = end ? (end - 1) : (strchr(ptr, 0) - 1);
 129 +
 130 +       //find partition number (assumes format root=/dev/mtdXX | /dev/mtdblockXX | yy:XX )
 131 +       for( i = 0; end >= ptr && *end >= '0' && *end <= '9'; end--, i++);
 132 +       ptr = end + 1;
 133 +
 134 +       /* if append-rootblock property is set use it to append to command line */
 135 +       rootblock = getprop(fdt, "/chosen", "append-rootblock", &l);
 136 +       if(rootblock != NULL) {
 137 +               if(*dest != ' ') {
 138 +                       *dest = ' ';
 139 +                       dest++;
 140 +                       len++;
 141 +               }
 142 +               if (len + l + i <= COMMAND_LINE_SIZE) {
 143 +                       memcpy(dest, rootblock, l);
 144 +                       dest += l - 1;
 145 +                       memcpy(dest, ptr, i);
 146 +                       dest += i;
 147 +               }
 148 +       }
 149 +       return dest;
 150 +}
 151 +#endif
 152 +
 153  static void merge_fdt_bootargs(void *fdt, const char *fdt_cmdline)
 154  {
 155         char cmdline[COMMAND_LINE_SIZE];
 156 @@ -88,18 +150,28 @@ static void merge_fdt_bootargs(void *fdt
 157
 158         /* and append the ATAG_CMDLINE */
 159         if (fdt_cmdline) {
 160 +
 161 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
 162 +               //save original bootloader args
 163 +               //and append ubi.mtd with root partition number to current cmdline
 164 +               setprop_string(fdt, "/chosen", "bootloader-args", fdt_cmdline);
 165 +               ptr = append_rootblock(ptr, fdt_cmdline, len, fdt);
 166 +
 167 +#else
 168                 len = strlen(fdt_cmdline);
 169                 if (ptr - cmdline + len + 2 < COMMAND_LINE_SIZE) {
 170                         *ptr++ = ' ';
 171                         memcpy(ptr, fdt_cmdline, len);
 172                         ptr += len;
 173                 }
 174 +#endif
 175         }
 176         *ptr = '\0';
 177
 178         setprop_string(fdt, "/chosen", "bootargs", cmdline);
 179  }
 180
 181 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
 182  static void hex_str(char *out, uint32_t value)
 183  {
 184         uint32_t digit;
 185 @@ -117,6 +189,7 @@ static void hex_str(char *out, uint32_t
 186         }
 187         *out = '\0';
 188  }
 189 +#endif
 190
 191  /*
 192   * Convert and fold provided ATAGs into the provided FDT.
 193 @@ -131,9 +204,11 @@ int atags_to_fdt(void *atag_list, void *
 194         struct tag *atag = atag_list;
 195         /* In the case of 64 bits memory size, need to reserve 2 cells for
 196          * address and size for each bank */
 197 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
 198         __be32 mem_reg_property[2 * 2 * NR_BANKS];
 199 -       int memcount = 0;
 200 -       int ret, memsize;
 201 +       int memsize, memcount = 0;
 202 +#endif
 203 +       int ret;
 204
 205         /* make sure we've got an aligned pointer */
 206         if ((u32)atag_list & 0x3)
 207 @@ -168,7 +243,9 @@ int atags_to_fdt(void *atag_list, void *
 208                         else
 209                                 setprop_string(fdt, "/chosen", "bootargs",
 210                                                atag->u.cmdline.cmdline);
 211 -               } else if (atag->hdr.tag == ATAG_MEM) {
 212 +               }
 213 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
 214 +               else if (atag->hdr.tag == ATAG_MEM) {
 215                         if (memcount >= sizeof(mem_reg_property)/4)
 216                                 continue;
 217                         if (!atag->u.mem.size)
 218 @@ -212,6 +289,10 @@ int atags_to_fdt(void *atag_list, void *
 219                 setprop(fdt, "/memory", "reg", mem_reg_property,
 220                         4 * memcount * memsize);
 221         }
 222 +#else
 223 +
 224 +       }
 225 +#endif
 226
 227         return fdt_pack(fdt);
 228  }
 229 --- a/init/main.c
 230 +++ b/init/main.c
 231 @@ -113,6 +113,10 @@
 232
 233  #include <kunit/test.h>
 234
 235 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
 236 +#include <linux/of.h>
 237 +#endif
 238 +
 239  static int kernel_init(void *);
 240
 241  extern void init_IRQ(void);
 242 @@ -993,6 +997,18 @@ asmlinkage __visible void __init __no_sa
 243         page_alloc_init();
 244
 245         pr_notice("Kernel command line: %s\n", saved_command_line);
 246 +
 247 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
 248 +       //Show bootloader's original command line for reference
 249 +       if(of_chosen) {
 250 +               const char *prop = of_get_property(of_chosen, "bootloader-args", NULL);
 251 +               if(prop)
 252 +                       pr_notice("Bootloader command line (ignored): %s\n", prop);
 253 +               else
 254 +                       pr_notice("Bootloader command line not present\n");
 255 +       }
 256 +#endif
 257 +
 258         /* parameters may set static keys */
 259         jump_label_init();
 260         parse_early_param();