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 z, k6 A6 x       sync ();* d* y8 d& J* g% r. X! g/ R8 ^  {
      *addr = 0;4 s2 @0 P5 K( C: q6 V
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      sync ();* }$ ^) d* r7 E4 m& F
      if ((val = *addr) != 0) {. Y9 A. m* T( `6 Q* w7 M6 j; N
            /* Restore the original data before leaving the function.6 R" Z8 B# c& J- {9 m$ _
               */# E+ K- S% f+ ^% S& x1 p8 j
            sync ();& X7 G  z# p( O- {- q7 C2 p, {! M
            *addr = save;* B- Z' `; z: q9 P8 o: D
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
  m) a7 B( t9 {                      addr  = base + cnt;
3 ]! t: H& O5 F! Z; h9 r. e                      sync ();
  d6 A$ X+ t9 V2 [  H                      *addr = save[--i];5 ]# B+ e) K. p+ z" O% q" q) }
            }, z* K, e& L: R! a4 v
            return (0);
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      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
- c9 N7 g. g& V% `             addr = base + cnt;       /* pointer arith! */
* A) H% v0 ~/ O  t2 @6 D4 {             val = *addr;
+ ~9 K- s5 h: R! V             *addr = save[--i];
1 U) P& {  G$ c8 z: }! s- z4 O             if (val != ~cnt) {: W2 l- s2 n% n* N$ ?: D
                     size = cnt * sizeof (long);8 a& B- s- s) b/ e& W- n
                     /* Restore the original data before leaving the function.
8 I7 f7 w! L9 w3 I                      */  |4 e9 B0 R/ c* U
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {* o4 T* `3 X1 D7 [( C1 l
                              addr  = base + cnt;- f( U6 q, A2 y0 [
                              *addr = save[--i];
- N0 K, x! R9 L                      }
5 x: k/ e3 y& L3 [) |& V6 e                      return (size);
* i, C# V. }' M+ u             }
( w+ A' {# S& W2 Q       }
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      return (maxsize);
% \# f! S* [8 l& d1 C}( h0 O7 L* p! S" u2 n- j
int dram_init(void)( k5 J; e3 m; e3 |
{
6 S  Y- y+ F4 g5 l! o$ g       /* dram_init must store complete ramsize in gd->ram_size */
) h3 K9 h3 W1 w: \& Y) P# I       gd->ram_size = get_ram_size(' u: k( Y, @( x$ o- H3 t/ z; E
                     (void *)CONFIG_SYS_SDRAM_BASE,7 c  W) r2 S, {1 C0 P- r
                     CONFIG_MAX_RAM_BANK_SIZE);
& y6 A6 v0 P' b& [- Q       return 0;
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FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！7 V1 f* X; y* b$ J- ], \+ c

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