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: n. X( t* o% G( Z       sync ();$ U( e* a' Y/ v9 M2 l
      *addr = 0;
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; Y' ]- @. q9 Q$ E       sync ();& g" N5 i6 U/ d
      if ((val = *addr) != 0) {
4 k7 M9 F' e# m, `5 s  z0 T$ _             /* Restore the original data before leaving the function.
6 F! ~; F% ^# R# ~1 d. e1 G                */
/ l& n  c* h' \" w0 j) Y* M' ~+ P             sync ();
- M0 ^' C3 u" [  d2 P$ }4 [! e             *addr = save;. A, d1 K7 u! |+ Z
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {" P/ z* `+ ^2 P# g( a4 |; B3 _
                     addr  = base + cnt;6 d8 S# T9 k) e9 l1 X
                     sync ();3 B4 M. a8 U+ E  U5 i' O/ X/ @* e
                     *addr = save[--i];
4 I4 M$ I5 n8 z6 O- j             }9 ?. I# \3 @, O! V/ {% n
            return (0);1 j# L) {# x! i' ?. [7 i
      }5 ^7 I% y7 o% f
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      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
: A% k) p$ x$ a5 z# {0 t* c             addr = base + cnt;       /* pointer arith! */
8 J0 G4 G* h, Y0 }0 E8 p. m  G% K* ?             val = *addr;
1 E5 d8 U; `9 ?; F$ Y2 x             *addr = save[--i];
- n$ z  O) y, B% @3 a; k6 Z             if (val != ~cnt) {
/ F7 B2 b: n2 J8 o6 i9 w; O                      size = cnt * sizeof (long);5 f; O1 t2 a3 q
                     /* Restore the original data before leaving the function.7 I! d  `  k! k  V
                     */  a3 w+ P% ]: t/ N$ z
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {" l$ ^$ ^9 ]5 s' r1 J+ C7 J
                              addr  = base + cnt;
- s( K$ c1 \1 ?) W- U9 z                               *addr = save[--i];
. W6 X9 s  a  \; P                      }" i# X# C! B& M& y
                     return (size);  p1 X( s* [' p+ b; N3 h5 [* Z
            }3 _/ ^8 e9 r3 u6 z
      }
4 ]; t2 P) p; c; [; E$ U/ U* q" R2 G+ a& e9 {$ M! k8 i% S# [
      return (maxsize);
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int dram_init(void)
$ E+ h5 V6 x5 o{- }& z: M, c9 n4 e# E5 ?; p
      /* dram_init must store complete ramsize in gd->ram_size */# F, V# @7 d( ^5 e: ]* O1 R
      gd->ram_size = get_ram_size(4 S8 n2 }& d5 s4 }- j! O* I
                     (void *)CONFIG_SYS_SDRAM_BASE,
4 E7 e2 ]6 g5 j0 C/ j  G                      CONFIG_MAX_RAM_BANK_SIZE);0 A* c& J' v( f) d
      return 0;7 N7 _- |9 j" K+ G% f0 l
}
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' T  e  u1 n7 q9 F+ V; w

5 c! I! v6 {4 IFLASH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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