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;
! R6 r+ W4 e- M' a& D( l& i       sync ();
/ D/ ]# u! {) R% d) h& [1 X       *addr = 0;/ H3 \8 C- m1 ^% U' L# u

& q; t  j: \2 U. \       sync ();
$ _: _+ I! {4 k9 z# q/ Z, h       if ((val = *addr) != 0) {
) s; U: ?, y7 M( F$ }             /* Restore the original data before leaving the function.
1 @2 U( ^8 H% j+ T                */
' H6 X  o  t/ ]* Q, t" [. r             sync ();
: c" j7 j4 {7 ~, k             *addr = save;' |2 n" Y- E/ F; x% ^
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {' G" U, ?7 _) c
                     addr  = base + cnt;* Q+ H8 n! e5 i* x( n1 |
                     sync ();" T1 x0 w2 P$ q8 M2 l& Z
                     *addr = save[--i];' p: t2 m+ n0 g( E1 y/ t' [
            }3 W% Z. ~  C8 W
            return (0);) \/ i2 w+ b& ]9 v; y
      }0 W" F, X) W; A. e. I9 F: k* Y+ O
8 E3 O8 Q, g- z2 Q0 P6 U
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
4 @& @7 [9 X, T% S: ?& `) ?             addr = base + cnt;       /* pointer arith! */
& k/ P3 ~& \6 f/ R# \, |             val = *addr;* @6 \/ f; D) ?$ V  w6 p
            *addr = save[--i];; N+ i8 W+ T/ m0 O
            if (val != ~cnt) {3 Y+ ?: }' |: z
                     size = cnt * sizeof (long);% h0 i" k6 I$ f, u6 |
                     /* Restore the original data before leaving the function.
0 a- l. }; w1 h) L/ n8 z8 s                      */
5 B. J$ y% ^2 A7 ?2 {                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
. u( x: r- a. I* a0 T                               addr  = base + cnt;
0 |) y( J& h# Z5 I* _3 d& v) n: s                               *addr = save[--i];! D. v4 g% t3 w+ v* w6 [
                     }
; j) d# s/ G: S/ X                      return (size);
+ u) q) a# t2 ~& f             }$ t5 }/ y$ f" A/ @" C
      }, z0 G& I  M3 j
: ^$ W+ _0 ?  K- w6 j4 D
      return (maxsize);
* O- y9 H# ?/ r2 W& m2 ?3 \, O/ @}7 e" {3 y9 @' O( L* L8 L+ x
int dram_init(void), r. y7 _! W$ g$ s
{( F# R5 m# V+ v4 f, v8 h: \  ^
      /* dram_init must store complete ramsize in gd->ram_size */3 V; o6 o/ Z3 v5 o$ P& d& Y
      gd->ram_size = get_ram_size($ B- M! S; F- U
                     (void *)CONFIG_SYS_SDRAM_BASE,1 g6 \9 X5 }) X1 Y
                     CONFIG_MAX_RAM_BANK_SIZE);% R% w* y' ]* p* p6 f
      return 0;2 t* g8 }( Y" R+ K7 A* j
}$ U+ C0 T) i+ [7 [2 f& l

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& h3 Q2 T) b  y4 s" c7 q, L, d

& i9 `5 p7 C" \# W' zFLASH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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