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;
$ c$ X# j/ D. t7 b       sync ();+ f. P; K: g! a! X' _, x
      *addr = 0;  K' h, U( A, g; O3 ]* n# V

: l9 Q. F! S3 R2 ?5 r- O& A  x       sync ();' Z& D; a% r9 y' j+ p
      if ((val = *addr) != 0) {
3 R; u6 Z! N6 Y) ~             /* Restore the original data before leaving the function.  N, z! a$ Q/ i
               */
- v0 {2 @# u3 j( H             sync ();( w+ a2 E* y1 I1 N- H% d
            *addr = save;  [6 _& r; d8 h7 p- s# ]
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {& j" m6 f5 j  H0 j/ G
                     addr  = base + cnt;
+ l$ d* H% t- P8 g" a2 S5 @' I                      sync ();
% B) T; w/ E  m1 e! _3 Y: \! Q                      *addr = save[--i];
& B* P& n# x( J* ]( m             }# K) @: r( @/ F. |4 h3 T
            return (0);- Q- o& C  I0 j5 i
      }. m0 e. I0 e' o) W- ]
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      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {! }0 B# `3 J7 f! A, s
            addr = base + cnt;       /* pointer arith! */3 N5 ~  A3 M; \( w% R% A
            val = *addr;
+ V5 n1 d' }  k; k             *addr = save[--i];
- ~0 b% l% s6 l, f! t             if (val != ~cnt) {
; [7 x& G2 S3 Y. r* i$ o7 c                      size = cnt * sizeof (long);
* Y' W9 Q6 N3 A8 U0 h1 j! u; I                      /* Restore the original data before leaving the function./ D( a2 O# s5 _- }* H' Y. x
                     */) K6 P8 c; a, M
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {+ n( k9 ]/ g0 f- G7 X
                              addr  = base + cnt;9 S# v% J0 F' o( u) ?! h; x
                              *addr = save[--i];
/ [3 s9 M/ H: }7 A8 o; x                      }
7 Q- H3 s- A. o! `( n                      return (size);' _; C9 p) d4 f& `* p$ Z- v
            }" i5 _* s" G# x* ?
      }" @3 ?% @6 d( y# r2 V" H) O. Z
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      return (maxsize);
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int dram_init(void)6 t- l3 _" j. U$ E: A( d8 k/ T
{5 F3 T$ E: p# F! U
      /* dram_init must store complete ramsize in gd->ram_size */3 d4 w& }" v# P5 y6 |, }
      gd->ram_size = get_ram_size(9 R  K# u( b. k$ v3 d/ C1 i9 M+ q
                     (void *)CONFIG_SYS_SDRAM_BASE," K' |3 h2 M% Y5 W
                     CONFIG_MAX_RAM_BANK_SIZE);4 m; ^. z- y8 u0 b& j8 Q3 r3 p  n  W8 p
      return 0;
, z$ D. m7 i% T& |5 a$ ]; ?4 u! ^! {}
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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！% s% g$ x6 P* @$ Z' {
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