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;
% P& l2 T7 c/ n       sync ();0 T# ?! ^& m" Y  R
      *addr = 0;
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      sync ();: e0 N  W. W, ?8 c- h
      if ((val = *addr) != 0) {
7 a) m3 n* b, j! h             /* Restore the original data before leaving the function.- q5 ~5 `3 N- D' y: C$ T, ]
               */
; S- p2 l: ]; _) J& W             sync ();1 n$ Q, s2 \" P7 w: k1 P5 E6 f
            *addr = save;# y" e8 H% Q* n8 P
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {/ E7 C+ l# l: a7 Y# D1 c
                     addr  = base + cnt;9 k7 Z2 a1 G" x) U8 x! Y
                     sync ();2 z& p) m* U# V/ C9 _2 u
                     *addr = save[--i];& A0 A+ W& R" j4 ]
            }
. Z7 z- Y  Z! E             return (0);& s, q; P- ?0 X
      }1 @2 D" ~; T& @: W* E5 H
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      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {, R" L# }( }& L$ z9 D8 n0 n
            addr = base + cnt;       /* pointer arith! */- M3 `  j# p  T& M" a8 {
            val = *addr;
, v- |3 g8 y& R" [7 E             *addr = save[--i];4 t# H  s4 C( d4 L2 b
            if (val != ~cnt) {
: O2 h: q$ I4 r( E5 ~+ o% K% y# \4 |                      size = cnt * sizeof (long);0 s3 t2 w2 x. t) P/ G/ y
                     /* Restore the original data before leaving the function.5 _* X3 u4 g, p7 c* w
                     */3 I/ }+ C5 U( A* S, }* X& U# o9 c
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {, U; ?1 i2 X  n* F% W2 w
                              addr  = base + cnt;
8 e1 P0 F0 U' ?, P                               *addr = save[--i];
/ L6 s  T' Q" k" A! c) `$ u( s! W: o                      }
4 F  R; v( x- r- r: x/ \) O                      return (size);( K4 y1 S+ h0 ?& _6 G: J) }) b& A
            }
% A. z  \- D8 p/ j       }8 z) N  `8 I6 Q
# s; q, B8 ]. z0 w4 k; ?% ?
      return (maxsize);! a, o" {7 l7 f7 @3 X" j
}% l* a) j, h$ f) w2 Z
int dram_init(void)  d% t: n0 u7 e# l( R9 i
{0 Q; J8 G; [% d/ C; V
      /* dram_init must store complete ramsize in gd->ram_size */
' @9 ^. Q  O* X  b       gd->ram_size = get_ram_size(, z2 J0 J; t8 @( A( I
                     (void *)CONFIG_SYS_SDRAM_BASE,( m; c. L3 Z) i1 j" l# l# Q  N4 C
                     CONFIG_MAX_RAM_BANK_SIZE);5 S0 v( `- Q6 c: ~4 p/ s
      return 0;! c  n, v  |6 D' G9 S/ D" t. o
}
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0 i( M6 `2 ?7 i! H7 {
5 e# M5 E. w* q9 r: ]. rFLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！
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