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;! E+ ~' c0 K* q, A8 o
      sync ();% z/ C) x+ m8 {/ ~
      *addr = 0;/ U% o1 f+ Q. v' w3 D

9 f; C/ M, t3 i       sync ();
/ g0 W; T! D# P& L1 \2 I0 V       if ((val = *addr) != 0) {
( e) m7 s! \; U0 \+ F$ Q6 P) z             /* Restore the original data before leaving the function.
6 G0 g0 N& C4 s$ O3 x) A; M                */
* d: k- k$ C8 c" d1 r  M7 a& n             sync ();
5 H5 S% X6 y* D' g6 j5 s+ s# _( D             *addr = save;
6 Q* e. X+ Y' g0 o             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {0 u8 _& @3 |6 ~/ U/ c
                     addr  = base + cnt;
" z/ i0 w/ Y1 [  c& K6 X                      sync ();" ]1 v! _2 v! ]$ p8 {$ M
                     *addr = save[--i];/ T; y# V" p. g0 K
            }
1 k* b; y: o2 |7 I' H  u& b0 }             return (0);2 G& Y$ ]% }% b: p+ o) ]
      }2 b2 \: Z4 B3 B" v; q

9 m. Z" ^' ^. k6 o( v       for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {$ G$ L" J+ A8 ^& o) v+ T
            addr = base + cnt;       /* pointer arith! */4 l: L5 K: x5 Y
            val = *addr;1 ]2 Q7 {1 D( p  n3 H
            *addr = save[--i];& z5 b3 n. {8 J
            if (val != ~cnt) {
, n9 L% {7 K& p1 x+ |                      size = cnt * sizeof (long);5 m( B8 t/ s9 ?; D5 R1 N. f) B
                     /* Restore the original data before leaving the function.
  G# C/ z8 N; F- ~+ G                      */
8 ~" h$ n# Z* i' n' y+ J* a; A) U                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
6 e5 `4 e5 F/ }7 \+ z                               addr  = base + cnt;
' u  N1 `! }: d6 u2 q                               *addr = save[--i];2 m# m, O* a( v
                     }
% f& a' s% g% {5 r8 N7 y& h                      return (size);8 _( {( d( @0 W
            }9 X: x+ V2 r4 r8 G" x# U$ V9 i; }2 e
      }# e, t  t6 l! x0 o9 p" d2 I
& w* B8 g3 x1 p, w
      return (maxsize);: N# D' G2 K5 u: O  N4 a: I
}, N7 V/ m: X. z" {1 T
int dram_init(void)+ t& t7 [0 E# v4 A6 D
{
3 X1 \# l' e- f+ k& e: c       /* dram_init must store complete ramsize in gd->ram_size */: R2 x- M( D& G! T* G  ^; q0 R/ s
      gd->ram_size = get_ram_size(6 D; D# p& n4 k/ f! e9 h
                     (void *)CONFIG_SYS_SDRAM_BASE,* m, M# I' S9 m. u
                     CONFIG_MAX_RAM_BANK_SIZE);4 v! z) J5 w% @( O& i) o
      return 0;) i& K2 K% J/ R, V# [' V8 B, R* N9 g. M
}' I0 m* X5 H6 e; G3 t. U2 m
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* C% Q: k) Y: C0 O2 MFLASH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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