target/linux/brcm47xx/patches-3.18/820-wgt634u-nvram-fix.patch

   1 The Netgear wgt634u uses a different format for storing the
   2 configuration. This patch is needed to read out the correct
   3 configuration. The cfe_env.c file uses a different method way to read
   4 out the configuration than the in kernel cfe config reader.
   5
   6 --- a/arch/mips/bcm47xx/Makefile
   7 +++ b/arch/mips/bcm47xx/Makefile
   8 @@ -5,3 +5,4 @@
   9
  10  obj-y                          += irq.o nvram.o prom.o serial.o setup.o time.o sprom.o
  11  obj-y                          += board.o buttons.o leds.o workarounds.o
  12 +obj-y                          += cfe_env.o
  13 --- /dev/null
  14 +++ b/arch/mips/bcm47xx/cfe_env.c
  15 @@ -0,0 +1,229 @@
  16 +/*
  17 + * CFE environment variable access
  18 + *
  19 + * Copyright 2001-2003, Broadcom Corporation
  20 + * Copyright 2006, Felix Fietkau <nbd@openwrt.org>
  21 + *
  22 + * This program is free software; you can redistribute  it and/or modify it
  23 + * under  the terms of  the GNU General  Public License as published by the
  24 + * Free Software Foundation;  either version 2 of the  License, or (at your
  25 + * option) any later version.
  26 + */
  27 +
  28 +#include <linux/init.h>
  29 +#include <linux/module.h>
  30 +#include <linux/kernel.h>
  31 +#include <linux/string.h>
  32 +#include <asm/io.h>
  33 +#include <asm/uaccess.h>
  34 +
  35 +#define NVRAM_SIZE       (0x1ff0)
  36 +static char _nvdata[NVRAM_SIZE];
  37 +static char _valuestr[256];
  38 +
  39 +/*
  40 + * TLV types.  These codes are used in the "type-length-value"
  41 + * encoding of the items stored in the NVRAM device (flash or EEPROM)
  42 + *
  43 + * The layout of the flash/nvram is as follows:
  44 + *
  45 + * <type> <length> <data ...> <type> <length> <data ...> <type_end>
  46 + *
  47 + * The type code of "ENV_TLV_TYPE_END" marks the end of the list.
  48 + * The "length" field marks the length of the data section, not
  49 + * including the type and length fields.
  50 + *
  51 + * Environment variables are stored as follows:
  52 + *
  53 + * <type_env> <length> <flags> <name> = <value>
  54 + *
  55 + * If bit 0 (low bit) is set, the length is an 8-bit value.
  56 + * If bit 0 (low bit) is clear, the length is a 16-bit value
  57 + *
  58 + * Bit 7 set indicates "user" TLVs.  In this case, bit 0 still
  59 + * indicates the size of the length field.
  60 + *
  61 + * Flags are from the constants below:
  62 + *
  63 + */
  64 +#define ENV_LENGTH_16BITS      0x00    /* for low bit */
  65 +#define ENV_LENGTH_8BITS       0x01
  66 +
  67 +#define ENV_TYPE_USER          0x80
  68 +
  69 +#define ENV_CODE_SYS(n,l) (((n)<<1)|(l))
  70 +#define ENV_CODE_USER(n,l) ((((n)<<1)|(l)) | ENV_TYPE_USER)
  71 +
  72 +/*
  73 + * The actual TLV types we support
  74 + */
  75 +
  76 +#define ENV_TLV_TYPE_END       0x00
  77 +#define ENV_TLV_TYPE_ENV       ENV_CODE_SYS(0,ENV_LENGTH_8BITS)
  78 +
  79 +/*
  80 + * Environment variable flags
  81 + */
  82 +
  83 +#define ENV_FLG_NORMAL         0x00    /* normal read/write */
  84 +#define ENV_FLG_BUILTIN                0x01    /* builtin - not stored in flash */
  85 +#define ENV_FLG_READONLY       0x02    /* read-only - cannot be changed */
  86 +
  87 +#define ENV_FLG_MASK           0xFF    /* mask of attributes we keep */
  88 +#define ENV_FLG_ADMIN          0x100   /* lets us internally override permissions */
  89 +
  90 +
  91 +/*  *********************************************************************
  92 +    *  _nvram_read(buffer,offset,length)
  93 +    *
  94 +    *  Read data from the NVRAM device
  95 +    *
  96 +    *  Input parameters:
  97 +    *             buffer - destination buffer
  98 +    *             offset - offset of data to read
  99 +    *             length - number of bytes to read
 100 +    *
 101 +    *  Return value:
 102 +    *             number of bytes read, or <0 if error occured
 103 +    ********************************************************************* */
 104 +static int
 105 +_nvram_read(unsigned char *nv_buf, unsigned char *buffer, int offset, int length)
 106 +{
 107 +    int i;
 108 +    if (offset > NVRAM_SIZE)
 109 +       return -1;
 110 +
 111 +    for ( i = 0; i < length; i++) {
 112 +       buffer[i] = ((volatile unsigned char*)nv_buf)[offset + i];
 113 +    }
 114 +    return length;
 115 +}
 116 +
 117 +
 118 +static char*
 119 +_strnchr(const char *dest,int c,size_t cnt)
 120 +{
 121 +       while (*dest && (cnt > 0)) {
 122 +       if (*dest == c) return (char *) dest;
 123 +       dest++;
 124 +       cnt--;
 125 +       }
 126 +       return NULL;
 127 +}
 128 +
 129 +
 130 +
 131 +/*
 132 + * Core support API: Externally visible.
 133 + */
 134 +
 135 +/*
 136 + * Get the value of an NVRAM variable
 137 + * @param      name    name of variable to get
 138 + * @return     value of variable or NULL if undefined
 139 + */
 140 +
 141 +char*
 142 +cfe_env_get(unsigned char *nv_buf, char* name)
 143 +{
 144 +    int size;
 145 +    unsigned char *buffer;
 146 +    unsigned char *ptr;
 147 +    unsigned char *envval;
 148 +    unsigned int reclen;
 149 +    unsigned int rectype;
 150 +    int offset;
 151 +    int flg;
 152 +
 153 +       if (!strcmp(name, "nvram_type"))
 154 +               return "cfe";
 155 +
 156 +    size = NVRAM_SIZE;
 157 +    buffer = &_nvdata[0];
 158 +
 159 +    ptr = buffer;
 160 +    offset = 0;
 161 +
 162 +    /* Read the record type and length */
 163 +    if (_nvram_read(nv_buf, ptr,offset,1) != 1) {
 164 +       goto error;
 165 +    }
 166 +
 167 +    while ((*ptr != ENV_TLV_TYPE_END)  && (size > 1)) {
 168 +
 169 +       /* Adjust pointer for TLV type */
 170 +       rectype = *(ptr);
 171 +       offset++;
 172 +       size--;
 173 +
 174 +       /*
 175 +        * Read the length.  It can be either 1 or 2 bytes
 176 +        * depending on the code
 177 +        */
 178 +       if (rectype & ENV_LENGTH_8BITS) {
 179 +           /* Read the record type and length - 8 bits */
 180 +           if (_nvram_read(nv_buf, ptr,offset,1) != 1) {
 181 +               goto error;
 182 +           }
 183 +           reclen = *(ptr);
 184 +           size--;
 185 +           offset++;
 186 +       }
 187 +       else {
 188 +           /* Read the record type and length - 16 bits, MSB first */
 189 +           if (_nvram_read(nv_buf, ptr,offset,2) != 2) {
 190 +               goto error;
 191 +           }
 192 +           reclen = (((unsigned int) *(ptr)) << 8) + (unsigned int) *(ptr+1);
 193 +           size -= 2;
 194 +           offset += 2;
 195 +       }
 196 +
 197 +       if (reclen > size)
 198 +           break;      /* should not happen, bad NVRAM */
 199 +
 200 +       switch (rectype) {
 201 +           case ENV_TLV_TYPE_ENV:
 202 +               /* Read the TLV data */
 203 +               if (_nvram_read(nv_buf, ptr,offset,reclen) != reclen)
 204 +                   goto error;
 205 +               flg = *ptr++;
 206 +               envval = (unsigned char *) _strnchr(ptr,'=',(reclen-1));
 207 +               if (envval) {
 208 +                   *envval++ = '\0';
 209 +                   memcpy(_valuestr,envval,(reclen-1)-(envval-ptr));
 210 +                   _valuestr[(reclen-1)-(envval-ptr)] = '\0';
 211 +#if 0
 212 +                   printk(KERN_INFO "NVRAM:%s=%s\n", ptr, _valuestr);
 213 +#endif
 214 +                   if(!strcmp(ptr, name)){
 215 +                       return _valuestr;
 216 +                   }
 217 +                   if((strlen(ptr) > 1) && !strcmp(&ptr[1], name))
 218 +                       return _valuestr;
 219 +               }
 220 +               break;
 221 +
 222 +           default:
 223 +               /* Unknown TLV type, skip it. */
 224 +               break;
 225 +           }
 226 +
 227 +       /*
 228 +        * Advance to next TLV
 229 +        */
 230 +
 231 +       size -= (int)reclen;
 232 +       offset += reclen;
 233 +
 234 +       /* Read the next record type */
 235 +       ptr = buffer;
 236 +       if (_nvram_read(nv_buf, ptr,offset,1) != 1)
 237 +           goto error;
 238 +       }
 239 +
 240 +error:
 241 +    return NULL;
 242 +
 243 +}
 244 +
 245 --- a/arch/mips/bcm47xx/nvram.c
 246 +++ b/arch/mips/bcm47xx/nvram.c
 247 @@ -22,6 +22,8 @@
 248
 249  static char nvram_buf[NVRAM_SPACE];
 250  static const u32 nvram_sizes[] = {0x8000, 0xF000, 0x10000};
 251 +static int cfe_env;
 252 +extern char *cfe_env_get(char *nv_buf, const char *name);
 253
 254  static u32 find_nvram_size(u32 end)
 255  {
 256 @@ -46,6 +48,26 @@ static int nvram_find_and_copy(u32 base,
 257         u32 *src, *dst;
 258         u32 size;
 259
 260 +       cfe_env = 0;
 261 +
 262 +       /* XXX: hack for supporting the CFE environment stuff on WGT634U */
 263 +       if (lim >= 8 * 1024 * 1024) {
 264 +               src = (u32 *) KSEG1ADDR(base + 8 * 1024 * 1024 - 0x2000);
 265 +               dst = (u32 *) nvram_buf;
 266 +
 267 +               if ((*src & 0xff00ff) == 0x000001) {
 268 +                       printk("early_nvram_init: WGT634U NVRAM found.\n");
 269 +
 270 +                       for (i = 0; i < 0x1ff0; i++) {
 271 +                               if (*src == 0xFFFFFFFF)
 272 +                                       break;
 273 +                               *dst++ = *src++;
 274 +                       }
 275 +                       cfe_env = 1;
 276 +                       return 0;
 277 +               }
 278 +       }
 279 +
 280         /* TODO: when nvram is on nand flash check for bad blocks first. */
 281         off = FLASH_MIN;
 282         while (off <= lim) {
 283 @@ -172,6 +194,13 @@ int bcm47xx_nvram_getenv(char *name, cha
 284                         return err;
 285         }
 286
 287 +       if (cfe_env) {
 288 +               value = cfe_env_get(nvram_buf, name);
 289 +               if (!value)
 290 +                       return -ENOENT;
 291 +               return snprintf(val, val_len, "%s", value);
 292 +       }
 293 +
 294         /* Look for name=value and return value */
 295         var = &nvram_buf[sizeof(struct nvram_header)];
 296         end = nvram_buf + sizeof(nvram_buf) - 2;