target/linux/mvebu/patches-6.1/300-mvebu-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 This patch has been modified to be mvebu specific. The original patch
  19 did not pass the bootloader cmdline on if no append-rootblock stanza
  20 was found, resulting in blank cmdline and failure to boot.
  21
  22 Signed-off-by: Michael Gray <michael.gray@lantisproject.com>
  23 ---
  24  arch/arm/Kconfig                        | 11 ++++
  25  arch/arm/boot/compressed/atags_to_fdt.c | 85 ++++++++++++++++++++++++-
  26  init/main.c                             | 16 +++++
  27  3 files changed, 111 insertions(+), 1 deletion(-)
  28
  29 --- a/arch/arm/Kconfig
  30 +++ b/arch/arm/Kconfig
  31 @@ -1587,6 +1587,17 @@ config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEN
  32           The command-line arguments provided by the boot loader will be
  33           appended to the the device tree bootargs property.
  34
  35 +config ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
  36 +       bool "Append rootblock parsing bootloader's kernel arguments"
  37 +       help
  38 +         The command-line arguments provided by the boot loader will be
  39 +         appended to a new device tree property: bootloader-args.
  40 +         If there is a property "append-rootblock" in DT under /chosen
  41 +         and a root= option in bootloaders command line it will be parsed
  42 +         and added to DT bootargs with the form: <append-rootblock>XX.
  43 +         Only command line ATAG will be processed, the rest of the ATAGs
  44 +         sent by bootloader will be ignored.
  45 +
  46  endchoice
  47
  48  config CMDLINE
  49 --- a/arch/arm/boot/compressed/atags_to_fdt.c
  50 +++ b/arch/arm/boot/compressed/atags_to_fdt.c
  51 @@ -5,6 +5,8 @@
  52
  53  #if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND)
  54  #define do_extend_cmdline 1
  55 +#elif defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
  56 +#define do_extend_cmdline 1
  57  #else
  58  #define do_extend_cmdline 0
  59  #endif
  60 @@ -20,6 +22,7 @@ static int node_offset(void *fdt, const
  61         return offset;
  62  }
  63
  64 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
  65  static int setprop(void *fdt, const char *node_path, const char *property,
  66                    void *val_array, int size)
  67  {
  68 @@ -28,6 +31,7 @@ static int setprop(void *fdt, const char
  69                 return offset;
  70         return fdt_setprop(fdt, offset, property, val_array, size);
  71  }
  72 +#endif
  73
  74  static int setprop_string(void *fdt, const char *node_path,
  75                           const char *property, const char *string)
  76 @@ -38,6 +42,7 @@ static int setprop_string(void *fdt, con
  77         return fdt_setprop_string(fdt, offset, property, string);
  78  }
  79
  80 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
  81  static int setprop_cell(void *fdt, const char *node_path,
  82                         const char *property, uint32_t val)
  83  {
  84 @@ -46,6 +51,7 @@ static int setprop_cell(void *fdt, const
  85                 return offset;
  86         return fdt_setprop_cell(fdt, offset, property, val);
  87  }
  88 +#endif
  89
  90  static const void *getprop(const void *fdt, const char *node_path,
  91                            const char *property, int *len)
  92 @@ -58,6 +64,7 @@ static const void *getprop(const void *f
  93         return fdt_getprop(fdt, offset, property, len);
  94  }
  95
  96 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
  97  static uint32_t get_cell_size(const void *fdt)
  98  {
  99         int len;
 100 @@ -69,6 +76,74 @@ static uint32_t get_cell_size(const void
 101         return cell_size;
 102  }
 103
 104 +#endif
 105 +
 106 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
 107 +
 108 +static char *append_rootblock(char *dest, const char *str, int len, void *fdt)
 109 +{
 110 +       const char *ptr, *end;
 111 +       const char *root="root=";
 112 +       int i, l;
 113 +       const char *rootblock;
 114 +
 115 +       //ARM doesn't have __HAVE_ARCH_STRSTR, so search manually
 116 +       ptr = str - 1;
 117 +
 118 +       do {
 119 +               //first find an 'r' at the begining or after a space
 120 +               do {
 121 +                       ptr++;
 122 +                       ptr = strchr(ptr, 'r');
 123 +                       if (!ptr)
 124 +                               goto no_append;
 125 +
 126 +               } while (ptr != str && *(ptr-1) != ' ');
 127 +
 128 +               //then check for the rest
 129 +               for(i = 1; i <= 4; i++)
 130 +                       if(*(ptr+i) != *(root+i)) break;
 131 +
 132 +       } while (i != 5);
 133 +
 134 +       end = strchr(ptr, ' ');
 135 +       end = end ? (end - 1) : (strchr(ptr, 0) - 1);
 136 +
 137 +       //find partition number (assumes format root=/dev/mtdXX | /dev/mtdblockXX | yy:XX )
 138 +       for( i = 0; end >= ptr && *end >= '0' && *end <= '9'; end--, i++);
 139 +       ptr = end + 1;
 140 +
 141 +       /* if append-rootblock property is set use it to append to command line */
 142 +       rootblock = getprop(fdt, "/chosen", "append-rootblock", &l);
 143 +       if (rootblock == NULL)
 144 +               goto no_append;
 145 +
 146 +       if (*dest != ' ') {
 147 +               *dest = ' ';
 148 +               dest++;
 149 +               len++;
 150 +       }
 151 +
 152 +       if (len + l + i <= COMMAND_LINE_SIZE) {
 153 +               memcpy(dest, rootblock, l);
 154 +               dest += l - 1;
 155 +               memcpy(dest, ptr, i);
 156 +               dest += i;
 157 +       }
 158 +
 159 +       return dest;
 160 +
 161 +no_append:
 162 +       len = strlen(str);
 163 +       if (len + 1 < COMMAND_LINE_SIZE) {
 164 +               memcpy(dest, str, len);
 165 +               dest += len;
 166 +       }
 167 +
 168 +       return dest;
 169 +}
 170 +#endif
 171 +
 172  static void merge_fdt_bootargs(void *fdt, const char *fdt_cmdline)
 173  {
 174         char cmdline[COMMAND_LINE_SIZE];
 175 @@ -88,18 +163,28 @@ static void merge_fdt_bootargs(void *fdt
 176
 177         /* and append the ATAG_CMDLINE */
 178         if (fdt_cmdline) {
 179 +
 180 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
 181 +               //save original bootloader args
 182 +               //and append ubi.mtd with root partition number to current cmdline
 183 +               setprop_string(fdt, "/chosen", "bootloader-args", fdt_cmdline);
 184 +               ptr = append_rootblock(ptr, fdt_cmdline, len, fdt);
 185 +
 186 +#else
 187                 len = strlen(fdt_cmdline);
 188                 if (ptr - cmdline + len + 2 < COMMAND_LINE_SIZE) {
 189                         *ptr++ = ' ';
 190                         memcpy(ptr, fdt_cmdline, len);
 191                         ptr += len;
 192                 }
 193 +#endif
 194         }
 195         *ptr = '\0';
 196
 197         setprop_string(fdt, "/chosen", "bootargs", cmdline);
 198  }
 199
 200 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
 201  static void hex_str(char *out, uint32_t value)
 202  {
 203         uint32_t digit;
 204 @@ -117,6 +202,7 @@ static void hex_str(char *out, uint32_t
 205         }
 206         *out = '\0';
 207  }
 208 +#endif
 209
 210  /*
 211   * Convert and fold provided ATAGs into the provided FDT.
 212 @@ -131,9 +217,11 @@ int atags_to_fdt(void *atag_list, void *
 213         struct tag *atag = atag_list;
 214         /* In the case of 64 bits memory size, need to reserve 2 cells for
 215          * address and size for each bank */
 216 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
 217         __be32 mem_reg_property[2 * 2 * NR_BANKS];
 218 -       int memcount = 0;
 219 -       int ret, memsize;
 220 +       int memsize, memcount = 0;
 221 +#endif
 222 +       int ret;
 223
 224         /* make sure we've got an aligned pointer */
 225         if ((u32)atag_list & 0x3)
 226 @@ -168,7 +256,9 @@ int atags_to_fdt(void *atag_list, void *
 227                         else
 228                                 setprop_string(fdt, "/chosen", "bootargs",
 229                                                atag->u.cmdline.cmdline);
 230 -               } else if (atag->hdr.tag == ATAG_MEM) {
 231 +               }
 232 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
 233 +               else if (atag->hdr.tag == ATAG_MEM) {
 234                         if (memcount >= sizeof(mem_reg_property)/4)
 235                                 continue;
 236                         if (!atag->u.mem.size)
 237 @@ -212,6 +302,10 @@ int atags_to_fdt(void *atag_list, void *
 238                 setprop(fdt, "/memory", "reg", mem_reg_property,
 239                         4 * memcount * memsize);
 240         }
 241 +#else
 242 +
 243 +       }
 244 +#endif
 245
 246         return fdt_pack(fdt);
 247  }
 248 --- a/init/main.c
 249 +++ b/init/main.c
 250 @@ -112,6 +112,10 @@
 251
 252  #include <kunit/test.h>
 253
 254 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
 255 +#include <linux/of.h>
 256 +#endif
 257 +
 258  static int kernel_init(void *);
 259
 260  extern void init_IRQ(void);
 261 @@ -993,6 +997,18 @@ asmlinkage __visible void __init __no_sa
 262         page_alloc_init();
 263
 264         pr_notice("Kernel command line: %s\n", saved_command_line);
 265 +
 266 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
 267 +       //Show bootloader's original command line for reference
 268 +       if(of_chosen) {
 269 +               const char *prop = of_get_property(of_chosen, "bootloader-args", NULL);
 270 +               if(prop)
 271 +                       pr_notice("Bootloader command line (ignored): %s\n", prop);
 272 +               else
 273 +                       pr_notice("Bootloader command line not present\n");
 274 +       }
 275 +#endif
 276 +
 277         /* parameters may set static keys */
 278         jump_label_init();
 279         parse_early_param();