TL138 uboot是怎么区分配置两款核心板的

Mr.Loser · 发表于 2014-9-11 09:33:39

核心板1：DDR2 128M Byte NAND FLASH 4G bit
核心板2：DDR2 256M Byte NAND FLASH 8G bit
这两个核心板公共一个uboot，DDR2的配置肯定是不同的，uboot怎么检查到是哪个核心板，然后去执行相应的配置呢？

是不是通过读NAND FLASH的ID，两款核心板NAND FLASH不同，ID也不同，这样读到了ID就知道是哪个核心板了？

2532609929 · 发表于 2014-9-11 18:55:41

DDR通过检查最大有效地址来识别容量，具体请看uboot的common/memsize.c文件中的检查代码，也可以看如下：
/*
* Check memory range for valid RAM. A simple memory test determines
* the actually available RAM size between addresses `base' and
* `base + maxsize'.
*/
long get_ram_size(long *base, long maxsize)
{
      volatile long *addr;
      long          save[32];
      long          cnt;
      long          val;
      long          size;
      int          i = 0;

      for (cnt = (maxsize / sizeof (long)) >> 1; cnt > 0; cnt >>= 1) {
            addr = base + cnt;       /* pointer arith! */
            sync ();
            save[i++] = *addr;
            sync ();
            *addr = ~cnt;
      }

      addr = base;
      sync ();
      save = *addr;1 E1 b3 X6 C% I2 I
      sync ();! f% A" s7 I) v; e- Z, W$ G
      *addr = 0;( [+ M( t  {+ N1 G3 ^' W% g
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      sync ();
! S$ z& p, Y# |+ E2 I       if ((val = *addr) != 0) {
  t6 P, `2 C6 S9 b; D" h             /* Restore the original data before leaving the function.2 y/ u3 z: k8 K) V
               */% Y: P/ {: @7 E' z, K
            sync ();/ S/ f* Z2 X4 a7 c- @4 n
            *addr = save;1 F/ `8 @* e3 K3 H
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
# h# p9 z$ \: |                      addr  = base + cnt;5 a5 J# y( P$ i7 K1 G
                     sync ();8 r( z- }0 X6 f& i1 E$ O1 z
                     *addr = save[--i];
9 S  p8 w& z, r             }
3 W1 D0 W* ~7 P             return (0);
$ M' a% l$ s6 t       }! l, p, S) w1 \4 h
* H3 \4 {, w) U$ ?
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
' V* X, J& `6 Y( V% h             addr = base + cnt;       /* pointer arith! */% [# ~; z6 m4 b- S! D
            val = *addr;& z5 g  j7 C" s1 O0 M
            *addr = save[--i];
2 j/ M$ k4 C  a4 [  N3 A             if (val != ~cnt) {
$ B1 o. x5 H( t4 Y) z3 w                      size = cnt * sizeof (long);5 }* v1 _9 W7 s' b2 c6 |
                     /* Restore the original data before leaving the function.
6 T8 `* m6 N9 X; @- F2 t0 h- Z                      */8 l- Y/ T& q* K. v
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {- O  p0 ~1 _* I. K( \5 f! J8 Q
                              addr  = base + cnt;
# {+ d. e: J0 e5 y" N                               *addr = save[--i];
$ D" @  r, S; e( T# A                      }  d' \; D2 N! @! C
                     return (size);+ a  r( K/ ?0 v  i
            }
* N' `: i* f' [, w       }
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      return (maxsize);( z& ?9 m* V; ?
}
6 K' `) q! H- X8 R2 Sint dram_init(void)
* U7 e3 l$ G1 [) |, B# b5 r{
' N0 b% N* N" P9 Q5 @* k: q  a       /* dram_init must store complete ramsize in gd->ram_size */0 a( X  h# q" G9 G) B( H. u
      gd->ram_size = get_ram_size(' j0 o: W- {% G; G/ o
                     (void *)CONFIG_SYS_SDRAM_BASE,
+ W  {+ w+ d" \  X: w' H2 r4 X. V                      CONFIG_MAX_RAM_BANK_SIZE);6 z$ ~$ v" q- r1 c; ^* l* `' p, K
      return 0;
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/ L8 A% y) U7 L3 f' PFLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！' p- ]' i+ _+ L' S
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