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;
, l0 R6 S% h8 h" c! ^       sync ();% x/ v( V# S5 E. E/ Q4 h/ Z- P
      *addr = 0;$ F! p3 L. B, j

' Y7 a+ E) w3 w6 ~4 x       sync ();
* {: _0 j  r/ R# Y( n+ i( e$ M1 Z       if ((val = *addr) != 0) {
; {" ^- R" F) U0 H+ A" |# C# j             /* Restore the original data before leaving the function.2 K  ]; ]' m) f/ h' _2 ~  V! a
               */* K2 @2 u) l# U' j0 c4 O5 Y
            sync ();
* \, k, t: c4 D; w/ ~             *addr = save;: s% @7 h! _  r% h; I; j2 N; _
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {" c5 |: U7 j7 ?$ m+ ?7 }9 t- ^- e
                     addr  = base + cnt;1 ^2 J& A6 Q/ i$ u
                     sync ();  V( q7 C2 n  r4 B7 m2 b) p
                     *addr = save[--i];& U4 |7 u8 }1 q; o( d
            }
7 L# P, T5 Z, E+ |             return (0);, V2 y/ X  }4 J) ?2 b; a. g
      }% Y4 U+ w$ t+ j7 X4 H

9 j+ b; ~. I# s9 c1 v  u9 }- }- K       for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {$ o+ s! |' @' G5 z8 J3 K
            addr = base + cnt;       /* pointer arith! */
7 {. K) V3 ~* J6 q, G: o             val = *addr;
6 q4 w. Z3 t- |  v+ }) H             *addr = save[--i];) K7 Z2 Q3 j$ w6 A4 a
            if (val != ~cnt) {
' `8 U/ n+ j) M2 w2 S4 u3 w* T2 C) b1 S                      size = cnt * sizeof (long);
6 q. z( R- h* O9 ^3 i                      /* Restore the original data before leaving the function.
$ C- O8 B1 Z  c" v; o: n                      */
) q1 X& I8 h" p2 W8 `) p6 E1 ]                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
. ~  \3 n. C# m                               addr  = base + cnt;9 j1 f2 e- P. k8 e5 s% R2 w1 a& I
                              *addr = save[--i];/ x, ~& d1 J3 }3 A
                     }
+ A2 f) }2 B; |0 a                      return (size);
1 r1 u4 K& b- ?& H             }* L' ?# Z+ N# p1 u2 u# _/ ~: @
      }
6 B: C* Z1 J+ |5 c. |0 b2 D- ^9 o8 d7 y) {5 ]: r
      return (maxsize);6 h5 x; }& }' U2 o  t) H" r5 ]
}
$ |% q7 i. m' v; l* zint dram_init(void)
' _' h; @1 K% H{
( h1 l, N5 ?6 q$ @7 l4 ~) }2 x# j       /* dram_init must store complete ramsize in gd->ram_size */
0 e$ F2 a! V* B# V% }0 c       gd->ram_size = get_ram_size(
8 b, w. v3 U! z* d; c                      (void *)CONFIG_SYS_SDRAM_BASE,! y9 r8 L0 `" n" W! W
                     CONFIG_MAX_RAM_BANK_SIZE);
2 i5 e- x6 d5 t4 H. Z( L       return 0;5 k  X( s6 h7 \: ?% w2 e
}
' |% z6 D2 i$ ]: b6 ^6 M- q* S2 [3 ~0 K( `
  m3 M* r% P' t, U* ^

# Q. k6 w! D* m' I
- ~2 O( y. B. \0 t' QFLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！: d6 b1 E5 t5 l( S" c, K8 ^% k
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