target/linux/brcm47xx/patches-2.6.38/820-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 @@ -3,4 +3,4 @@
   9  # under Linux.
  10  #
  11
  12 -obj-y := gpio.o irq.o nvram.o prom.o serial.o setup.o time.o
  13 +obj-y := gpio.o irq.o nvram.o prom.o serial.o setup.o time.o cfe_env.o
  14 --- /dev/null
  15 +++ b/arch/mips/bcm47xx/cfe_env.c
  16 @@ -0,0 +1,229 @@
  17 +/*
  18 + * CFE environment variable access
  19 + *
  20 + * Copyright 2001-2003, Broadcom Corporation
  21 + * Copyright 2006, Felix Fietkau <nbd@openwrt.org>
  22 + *
  23 + * This program is free software; you can redistribute  it and/or modify it
  24 + * under  the terms of  the GNU General  Public License as published by the
  25 + * Free Software Foundation;  either version 2 of the  License, or (at your
  26 + * option) any later version.
  27 + */
  28 +
  29 +#include <linux/init.h>
  30 +#include <linux/module.h>
  31 +#include <linux/kernel.h>
  32 +#include <linux/string.h>
  33 +#include <asm/io.h>
  34 +#include <asm/uaccess.h>
  35 +
  36 +#define NVRAM_SIZE       (0x1ff0)
  37 +static char _nvdata[NVRAM_SIZE];
  38 +static char _valuestr[256];
  39 +
  40 +/*
  41 + * TLV types.  These codes are used in the "type-length-value"
  42 + * encoding of the items stored in the NVRAM device (flash or EEPROM)
  43 + *
  44 + * The layout of the flash/nvram is as follows:
  45 + *
  46 + * <type> <length> <data ...> <type> <length> <data ...> <type_end>
  47 + *
  48 + * The type code of "ENV_TLV_TYPE_END" marks the end of the list.
  49 + * The "length" field marks the length of the data section, not
  50 + * including the type and length fields.
  51 + *
  52 + * Environment variables are stored as follows:
  53 + *
  54 + * <type_env> <length> <flags> <name> = <value>
  55 + *
  56 + * If bit 0 (low bit) is set, the length is an 8-bit value.
  57 + * If bit 0 (low bit) is clear, the length is a 16-bit value
  58 + *
  59 + * Bit 7 set indicates "user" TLVs.  In this case, bit 0 still
  60 + * indicates the size of the length field.
  61 + *
  62 + * Flags are from the constants below:
  63 + *
  64 + */
  65 +#define ENV_LENGTH_16BITS      0x00    /* for low bit */
  66 +#define ENV_LENGTH_8BITS       0x01
  67 +
  68 +#define ENV_TYPE_USER          0x80
  69 +
  70 +#define ENV_CODE_SYS(n,l) (((n)<<1)|(l))
  71 +#define ENV_CODE_USER(n,l) ((((n)<<1)|(l)) | ENV_TYPE_USER)
  72 +
  73 +/*
  74 + * The actual TLV types we support
  75 + */
  76 +
  77 +#define ENV_TLV_TYPE_END       0x00
  78 +#define ENV_TLV_TYPE_ENV       ENV_CODE_SYS(0,ENV_LENGTH_8BITS)
  79 +
  80 +/*
  81 + * Environment variable flags
  82 + */
  83 +
  84 +#define ENV_FLG_NORMAL         0x00    /* normal read/write */
  85 +#define ENV_FLG_BUILTIN                0x01    /* builtin - not stored in flash */
  86 +#define ENV_FLG_READONLY       0x02    /* read-only - cannot be changed */
  87 +
  88 +#define ENV_FLG_MASK           0xFF    /* mask of attributes we keep */
  89 +#define ENV_FLG_ADMIN          0x100   /* lets us internally override permissions */
  90 +
  91 +
  92 +/*  *********************************************************************
  93 +    *  _nvram_read(buffer,offset,length)
  94 +    *
  95 +    *  Read data from the NVRAM device
  96 +    *
  97 +    *  Input parameters:
  98 +    *             buffer - destination buffer
  99 +    *             offset - offset of data to read
 100 +    *             length - number of bytes to read
 101 +    *
 102 +    *  Return value:
 103 +    *             number of bytes read, or <0 if error occured
 104 +    ********************************************************************* */
 105 +static int
 106 +_nvram_read(unsigned char *nv_buf, unsigned char *buffer, int offset, int length)
 107 +{
 108 +    int i;
 109 +    if (offset > NVRAM_SIZE)
 110 +       return -1;
 111 +
 112 +    for ( i = 0; i < length; i++) {
 113 +       buffer[i] = ((volatile unsigned char*)nv_buf)[offset + i];
 114 +    }
 115 +    return length;
 116 +}
 117 +
 118 +
 119 +static char*
 120 +_strnchr(const char *dest,int c,size_t cnt)
 121 +{
 122 +       while (*dest && (cnt > 0)) {
 123 +       if (*dest == c) return (char *) dest;
 124 +       dest++;
 125 +       cnt--;
 126 +       }
 127 +       return NULL;
 128 +}
 129 +
 130 +
 131 +
 132 +/*
 133 + * Core support API: Externally visible.
 134 + */
 135 +
 136 +/*
 137 + * Get the value of an NVRAM variable
 138 + * @param      name    name of variable to get
 139 + * @return     value of variable or NULL if undefined
 140 + */
 141 +
 142 +char*
 143 +cfe_env_get(unsigned char *nv_buf, char* name)
 144 +{
 145 +    int size;
 146 +    unsigned char *buffer;
 147 +    unsigned char *ptr;
 148 +    unsigned char *envval;
 149 +    unsigned int reclen;
 150 +    unsigned int rectype;
 151 +    int offset;
 152 +    int flg;
 153 +
 154 +       if (!strcmp(name, "nvram_type"))
 155 +               return "cfe";
 156 +
 157 +    size = NVRAM_SIZE;
 158 +    buffer = &_nvdata[0];
 159 +
 160 +    ptr = buffer;
 161 +    offset = 0;
 162 +
 163 +    /* Read the record type and length */
 164 +    if (_nvram_read(nv_buf, ptr,offset,1) != 1) {
 165 +       goto error;
 166 +    }
 167 +
 168 +    while ((*ptr != ENV_TLV_TYPE_END)  && (size > 1)) {
 169 +
 170 +       /* Adjust pointer for TLV type */
 171 +       rectype = *(ptr);
 172 +       offset++;
 173 +       size--;
 174 +
 175 +       /*
 176 +        * Read the length.  It can be either 1 or 2 bytes
 177 +        * depending on the code
 178 +        */
 179 +       if (rectype & ENV_LENGTH_8BITS) {
 180 +           /* Read the record type and length - 8 bits */
 181 +           if (_nvram_read(nv_buf, ptr,offset,1) != 1) {
 182 +               goto error;
 183 +           }
 184 +           reclen = *(ptr);
 185 +           size--;
 186 +           offset++;
 187 +       }
 188 +       else {
 189 +           /* Read the record type and length - 16 bits, MSB first */
 190 +           if (_nvram_read(nv_buf, ptr,offset,2) != 2) {
 191 +               goto error;
 192 +           }
 193 +           reclen = (((unsigned int) *(ptr)) << 8) + (unsigned int) *(ptr+1);
 194 +           size -= 2;
 195 +           offset += 2;
 196 +       }
 197 +
 198 +       if (reclen > size)
 199 +           break;      /* should not happen, bad NVRAM */
 200 +
 201 +       switch (rectype) {
 202 +           case ENV_TLV_TYPE_ENV:
 203 +               /* Read the TLV data */
 204 +               if (_nvram_read(nv_buf, ptr,offset,reclen) != reclen)
 205 +                   goto error;
 206 +               flg = *ptr++;
 207 +               envval = (unsigned char *) _strnchr(ptr,'=',(reclen-1));
 208 +               if (envval) {
 209 +                   *envval++ = '\0';
 210 +                   memcpy(_valuestr,envval,(reclen-1)-(envval-ptr));
 211 +                   _valuestr[(reclen-1)-(envval-ptr)] = '\0';
 212 +#if 0
 213 +                   printk(KERN_INFO "NVRAM:%s=%s\n", ptr, _valuestr);
 214 +#endif
 215 +                   if(!strcmp(ptr, name)){
 216 +                       return _valuestr;
 217 +                   }
 218 +                   if((strlen(ptr) > 1) && !strcmp(&ptr[1], name))
 219 +                       return _valuestr;
 220 +               }
 221 +               break;
 222 +
 223 +           default:
 224 +               /* Unknown TLV type, skip it. */
 225 +               break;
 226 +           }
 227 +
 228 +       /*
 229 +        * Advance to next TLV
 230 +        */
 231 +
 232 +       size -= (int)reclen;
 233 +       offset += reclen;
 234 +
 235 +       /* Read the next record type */
 236 +       ptr = buffer;
 237 +       if (_nvram_read(nv_buf, ptr,offset,1) != 1)
 238 +           goto error;
 239 +       }
 240 +
 241 +error:
 242 +    return NULL;
 243 +
 244 +}
 245 +
 246 --- a/arch/mips/bcm47xx/nvram.c
 247 +++ b/arch/mips/bcm47xx/nvram.c
 248 @@ -22,6 +22,8 @@
 249  #include <asm/mach-bcm47xx/bcm47xx.h>
 250
 251  static char nvram_buf[NVRAM_SPACE];
 252 +static int cfe_env;
 253 +extern char *cfe_env_get(char *nv_buf, const char *name);
 254
 255  /* Probe for NVRAM header */
 256  static void early_nvram_init(void)
 257 @@ -34,6 +36,25 @@ static void early_nvram_init(void)
 258
 259         base = mcore->flash_window;
 260         lim = mcore->flash_window_size;
 261 +       cfe_env = 0;
 262 +
 263 +       /* XXX: hack for supporting the CFE environment stuff on WGT634U */
 264 +       if (lim >= 8 * 1024 * 1024) {
 265 +               src = (u32 *) KSEG1ADDR(base + 8 * 1024 * 1024 - 0x2000);
 266 +               dst = (u32 *) nvram_buf;
 267 +
 268 +               if ((*src & 0xff00ff) == 0x000001) {
 269 +                       printk("early_nvram_init: WGT634U NVRAM found.\n");
 270 +
 271 +                       for (i = 0; i < 0x1ff0; i++) {
 272 +                               if (*src == 0xFFFFFFFF)
 273 +                                       break;
 274 +                               *dst++ = *src++;
 275 +                       }
 276 +                       cfe_env = 1;
 277 +                       return;
 278 +               }
 279 +       }
 280
 281         off = FLASH_MIN;
 282         while (off <= lim) {
 283 @@ -75,6 +96,12 @@ int nvram_getenv(char *name, char *val,
 284         if (!nvram_buf[0])
 285                 early_nvram_init();
 286
 287 +       if (cfe_env) {
 288 +               value = cfe_env_get(nvram_buf, name);
 289 +               snprintf(val, val_len, "%s", value);
 290 +               return 0;
 291 +       }
 292 +
 293         /* Look for name=value and return value */
 294         var = &nvram_buf[sizeof(struct nvram_header)];
 295         end = nvram_buf + sizeof(nvram_buf) - 2;
 296 @@ -104,6 +131,9 @@ char *nvram_get(const char *name)
 297         if (!nvram_buf[0])
 298                 early_nvram_init();
 299
 300 +       if (cfe_env)
 301 +               return cfe_env_get(nvram_buf, name);
 302 +
 303         /* Look for name=value and return value */
 304         var = &nvram_buf[sizeof(struct nvram_header)];
 305         end = nvram_buf + sizeof(nvram_buf) - 2;