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;& \# Y; J. X, r4 a0 b
      sync ();8 W: t* P4 S, ]/ Q
      *addr = 0;( L* }# I- Q, m1 y. m2 E
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      sync ();/ y4 I; a+ p& Z$ c7 e  g$ @
      if ((val = *addr) != 0) {- G4 `" {# A1 W! I  D
            /* Restore the original data before leaving the function.' Z) z% t) Q& w; U
               */8 B$ }2 E. M: @: ^1 t
            sync ();
7 z# H7 g( h/ Q- W: k9 R2 Z1 T             *addr = save;6 }* n' C5 x6 ]& `1 @  ]. u3 v# F# v
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
. ]; {' T: n; I( K                      addr  = base + cnt;% V0 z4 f& w( D* I# o& Q& V
                     sync ();/ C$ @) H( [9 z3 K
                     *addr = save[--i];
" U! s" r( Y. Q- m) e             }+ P8 R* @0 l+ T' |1 C1 u
            return (0);
) {# K3 S/ D' \7 M9 ]7 N       }: m. f. J: O" I$ j
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      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {3 _( R$ r  E) D' ?# F% Y( f) j
            addr = base + cnt;       /* pointer arith! */4 j+ N. J+ o: W& E  p6 Q0 ?& [
            val = *addr;
1 }% m2 c6 k. e5 Z             *addr = save[--i];* Y- i! h% a( T) g1 A4 m% Q7 ]
            if (val != ~cnt) {3 t7 c! `0 N! d3 L4 t
                     size = cnt * sizeof (long);
, y9 U7 e+ ]/ d7 U                      /* Restore the original data before leaving the function.3 U' Z6 R' {1 M- v
                     */5 N+ o6 R  ^3 N5 K
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
4 H: H( `% w$ d                               addr  = base + cnt;
7 x4 Z# p9 {  ^) Q" e- P                               *addr = save[--i];
# x5 A/ P8 J5 Q                      }3 m  E; e2 N& d- V6 B
                     return (size);
# M3 b% j2 m, B) M* t: X$ r             }
, Q9 E" d# m/ x# ~, G       }
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      return (maxsize);$ t: X4 |6 V  V8 }; O+ j
}
$ r: d& `; ^( d+ S+ }' n# ]int dram_init(void)& A; B: y! O2 h+ L6 {) O
{
" }' V) l, f; }% ?# f       /* dram_init must store complete ramsize in gd->ram_size */
1 C8 `# C! P. ]6 L: Q+ f2 c9 u       gd->ram_size = get_ram_size(# d' Y4 B) O) |9 A
                     (void *)CONFIG_SYS_SDRAM_BASE,: B  q# t6 m! x4 F
                     CONFIG_MAX_RAM_BANK_SIZE);& Z+ V9 i! O" \) u$ |2 L
      return 0;" x. _0 d) D# [% S
}6 Z2 y! `# {6 l1 d6 e- S+ j" [
0 J3 I: L1 r, F" i

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( C+ e7 t. d( x" j; LFLASH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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