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;; W9 Q4 ]7 U4 a( Q: [
      sync ();
1 G3 l2 q+ O+ _0 h" ]       *addr = 0;2 p* c# D/ N2 t; f( b1 W3 \+ S

2 _% U+ w: V9 b7 W2 U# j* W       sync ();- Q+ A5 E( U. O* Q9 N7 ]' p( @
      if ((val = *addr) != 0) {: ?* ~5 L7 t' D4 }4 D& y* g
            /* Restore the original data before leaving the function.5 B5 e! o; e0 @1 h, B
               */
8 a4 }% R  \/ f0 Y$ h             sync ();' N1 c7 F9 }( c; x( g2 E
            *addr = save;
9 _/ n4 ~7 T7 v5 ^             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {0 V) S# X; j8 f) l0 Z
                     addr  = base + cnt;
0 j, s& P5 T7 X% y, ^  q  g                      sync ();, b: ~6 S6 ]. S5 {
                     *addr = save[--i];, A1 p% Z7 y# ^* V1 a6 l$ v& j3 X
            }
            return (0);
8 g$ A4 V8 R, P( e& N       }
7 i( n# _: p( n, |9 m- \6 Q$ [% v! [$ r8 V2 M' j
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {$ ^6 z" @2 U% a7 v
            addr = base + cnt;       /* pointer arith! */
" r: |' `  A3 ^% {$ A4 d7 }  ?             val = *addr;8 x, K3 `7 r7 T3 I6 k# ~& p8 V
            *addr = save[--i];
0 H# q: p& j8 |5 X  k+ M* w             if (val != ~cnt) {
' |! F4 `/ g: ^6 L: y/ Y2 U                      size = cnt * sizeof (long);1 X* M: I2 G8 q3 h$ G
                     /* Restore the original data before leaving the function.
% N0 T& f' S; H; q                      */
0 N1 b0 L, X5 q' |. y0 F$ @                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {# }  P/ M# w/ g+ T
                              addr  = base + cnt;1 Q6 P) P) }$ i6 ?5 j
                              *addr = save[--i];' v( o. A; H! }( S$ V8 B% q% {
                     }
: {% Q, n  v2 s                      return (size);
% L8 p1 r  D6 D( @/ o             }, B( P8 B* _/ y2 ~9 f8 K& O  u
      }
  A* q& i0 U5 H. S1 J6 T  ~  [5 I8 Z4 T3 n" t$ n
      return (maxsize);9 i+ _. w" g' ?6 m# X4 v2 a* D
}/ C' W8 t' J( O# q; o$ ?
int dram_init(void)
8 m9 o! h( o" B- z! J, f{
5 d1 v, l; ~; W4 I! k  r       /* dram_init must store complete ramsize in gd->ram_size */
- D) m8 S0 K5 i& V" R! |9 G' G       gd->ram_size = get_ram_size(
+ Y2 a9 N) L6 H: r                      (void *)CONFIG_SYS_SDRAM_BASE,# N8 U* K$ b, }( x0 c& P
                     CONFIG_MAX_RAM_BANK_SIZE);" k( ?% g; {1 o* c2 [1 |
      return 0;. i" A3 x3 }0 V9 y5 Y% \. {
}  [- }3 D  Q) ?- v2 a
8 h  z8 M' J. Y/ j
& A( I* f0 [  {# F- ~6 g& t
7 |  T4 Q4 u0 `& @* x

" ?) u7 x  F  |# A5 cFLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！" X) ]; R0 ^" F/ n2 m; M

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