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;- O% D! q5 m  b' s  B
      sync ();) ?' `! ?$ ^# J
      *addr = 0;
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      sync ();
2 H! h0 Q" |$ M       if ((val = *addr) != 0) {1 r# [# ~- q; k4 g/ v
            /* Restore the original data before leaving the function.* Q7 z# ]; h- j' v
               */- P4 e. G! d$ P$ E0 p( @. y6 y
            sync ();
+ I' v( R+ ~& s( b' R, Q             *addr = save;
6 d$ B4 D+ T7 q- d- `             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
% ~/ _: j: _& p                      addr  = base + cnt;* F0 U5 o6 s: Z
                     sync ();
# v4 y& g1 b0 T& l& T2 r                      *addr = save[--i];
5 Z( N7 S- l9 p7 Z9 }. u: Y; s             }
& v2 k9 j3 G1 h0 P8 _8 p" h             return (0);
6 ^% I$ P, \  c6 ?2 k; ]& R       }
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      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
0 ^$ ?3 z! ?0 q# c2 o$ i3 T. b             addr = base + cnt;       /* pointer arith! */7 }5 P9 W2 g4 m! v
            val = *addr;
- e8 A6 J* d' {6 p             *addr = save[--i];" m. q5 j2 g, t8 s: O* O9 ^
            if (val != ~cnt) {
% T8 |: p2 w2 z( g& p& V; F                      size = cnt * sizeof (long);) r4 L& s, O1 K/ R4 x* J
                     /* Restore the original data before leaving the function.7 D3 Z0 P' m# f" X1 b
                     */) y! U4 s. x) x: ~/ D
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {2 k* i- B6 `- Y' j" Q0 G( H
                              addr  = base + cnt;: u4 }5 ]7 Z1 k/ y# k
                              *addr = save[--i];. G1 `  G8 k9 N+ O
                     }
1 n- D# s3 ~" C5 Y- K: Z- S                      return (size);2 d% ~: Y' T  x; ~% Y0 R
            }; y0 `& ~- u$ D% b" c+ X
      }& E* Q4 N, w" H  E

4 R9 K3 s4 I9 S- S& R( E6 C, |; l       return (maxsize);3 }4 ?8 h% ^( [0 J; Q2 Y& L
}* \/ w/ F# h' F# l" q: n
int dram_init(void)
) t( k7 r: e3 ?  q! t3 m4 `2 R3 D{
7 w+ y+ v/ l6 f# ~, s       /* dram_init must store complete ramsize in gd->ram_size */
, B& F2 s) A1 \5 ~       gd->ram_size = get_ram_size(
, c' a' e. r* f6 }; J; ~+ l+ m                      (void *)CONFIG_SYS_SDRAM_BASE,2 x! t1 K7 e; j* S7 h
                     CONFIG_MAX_RAM_BANK_SIZE);, Y: }  f* b2 x* ~& G
      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！" p1 b  Y6 Z/ v! M- ?$ m) D! L" X

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