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;5 Z; j' J: S" t
      sync ();% q. w8 \- |9 ^) @  p, _5 I6 P
      *addr = 0;
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      sync ();6 N2 \  B) G2 r) I3 A
      if ((val = *addr) != 0) {" z; u  p3 @# w, I  d1 E
            /* Restore the original data before leaving the function.  _5 n, K( N* g
               */8 Q. Q9 @. |# v* o
            sync ();! p& I2 @  U6 b# M2 M
            *addr = save;
2 X( u$ X, ^2 t             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
3 r& v7 p. o, U% W8 M: x                      addr  = base + cnt;
6 a5 I3 ~; g7 A' B$ I4 L                      sync ();0 X8 u9 u- R# l+ W+ u
                     *addr = save[--i];
5 F# v: C7 G: P             }
. z5 s4 l' `, w' q             return (0);
6 X% a# y6 t3 M  w) R       }( l0 d; q. ?0 h* B+ o

( m5 I1 m# ~0 r' X8 I       for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
% c0 [7 D" A3 Y) q) c' T6 v             addr = base + cnt;       /* pointer arith! */
& N- a8 C$ o) R$ J( G0 }- H             val = *addr;
, B; Z1 q, R9 X             *addr = save[--i];8 s' t6 T5 M9 Q) N. J+ q
            if (val != ~cnt) {
" T& V: ~8 n6 @" O2 G" X                      size = cnt * sizeof (long);7 P4 @0 g2 Y+ L$ ~2 m
                     /* Restore the original data before leaving the function.6 f# t+ T* I* b. L
                     */
, ~4 h/ s, b  B$ ]                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {7 O* p* S8 K3 q6 J) ?2 Y
                              addr  = base + cnt;; z! n7 X5 v$ Q
                              *addr = save[--i];
( w9 F- V6 Y% T1 F$ v6 f                      }
& ~2 j( x8 y4 x' p$ e                      return (size);
3 p2 R* {0 }8 X             }
3 e) Z6 P% }4 C       }
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      return (maxsize);0 H% k' g. g% e, H1 T
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int dram_init(void)
" J# n4 O. R/ z# C: _{
2 C$ s5 f& \6 \' |       /* dram_init must store complete ramsize in gd->ram_size */
+ P! {1 P. Y  k8 Q       gd->ram_size = get_ram_size(
; A7 ~9 b% _7 m/ W8 r                      (void *)CONFIG_SYS_SDRAM_BASE,
# ~- A5 a  [7 l0 t                      CONFIG_MAX_RAM_BANK_SIZE);; O5 O) w, U3 m( u3 y- c3 w
      return 0;
, E3 {) G5 b: L: P# v. U}
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FLASH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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