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;4 S% Y. }+ n& x6 s* {, i, c
      sync ();
  d0 q' o, _. y$ i2 A1 R       *addr = 0;
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      sync ();- Z  V7 E) F- f# M- o+ t7 m
      if ((val = *addr) != 0) {
3 E& i: c1 x: @& B             /* Restore the original data before leaving the function.. j- V( m2 Y0 x; t! w  i
               */
6 u" P8 Y8 q, L0 \1 d9 z             sync ();
; _7 f9 n# a. x             *addr = save;) q6 i# n/ T  u- y2 a
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
8 r/ Y5 W# ~! f/ W; ]# i  q9 h4 E                      addr  = base + cnt;
* P4 x5 I) ]( {! D                      sync ();
1 B4 J& M' H# a( ?* _                      *addr = save[--i];
8 ~" f6 g) G% j: O5 g* _             }6 m3 ^3 o2 M2 @+ k" D! K3 v
            return (0);* a% p8 K) q+ n3 r- z# r2 I
      }6 g6 _  l* r. Z/ j; s! }

4 ?. H5 M, k# Q! Q4 @2 h! S       for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
: }+ _  U) }0 [             addr = base + cnt;       /* pointer arith! */
) j" C+ n3 Y0 ^0 F6 p& ]+ G& b             val = *addr;2 Z0 Q3 ^9 Q. `
            *addr = save[--i];
+ Z7 a5 N8 S, d5 {9 b             if (val != ~cnt) {
/ o. b# L$ ?- V, ]) w                      size = cnt * sizeof (long);
) f0 S$ i- f; m+ J7 d  k3 v' A: e                      /* Restore the original data before leaving the function.4 w0 a# q) J" G2 i) s
                     */5 V! Z5 u# |- R) a
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {! ^& ^7 K: i! N  A% v. F
                              addr  = base + cnt;% A7 i' r$ y0 X/ o. g+ \& U
                              *addr = save[--i];: ^6 K6 m5 ?( r3 V& \% g
                     }
, g/ H0 }6 L3 s+ G6 E7 W- `                      return (size);
$ x4 s, Z# H; ^, ?: J             }- C5 ?7 X, c9 \2 Y, n
      }
# X" Z5 Y! ~7 T5 W- _( ^; C: r+ g% Q: {) `
      return (maxsize);
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int dram_init(void)
3 m6 E, l! a( ]& \0 x; w  D! M+ }{
1 A/ O! S9 V! I( Z' e: C. g  t       /* dram_init must store complete ramsize in gd->ram_size */
      gd->ram_size = get_ram_size(: h9 g9 W; U, W( R( r; @3 D6 }
                     (void *)CONFIG_SYS_SDRAM_BASE,
$ v6 N7 H$ D* B; _4 n7 v3 N                      CONFIG_MAX_RAM_BANK_SIZE);! R8 N( o# L) C' d" Y* P1 W
      return 0;6 w% {9 {2 s. N: E
}
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7 L. R8 ~  w# h- P, Z$ q6 _4 q& u0 s- q2 C2 a
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' r5 x7 _( |: d5 y: K  ^/ ?
FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！3 b: |, z- z$ f+ u1 M

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