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;6 i" k: s3 K1 Q7 s/ f% i9 D
      sync ();
0 N% H% Y# Q6 `$ d       *addr = 0;
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. z$ P; V0 X1 g% m6 F# Z5 Y       sync ();! n' {: w. ^2 L$ X0 O7 w
      if ((val = *addr) != 0) {
. a+ `- w* b! }1 r" r8 w# ]3 e  x             /* Restore the original data before leaving the function., U9 Z* P1 L5 o: v- `* C
               */0 i! `$ e; f) U
            sync ();
$ P# {8 r. p) e' }9 h+ O; ?" j3 x             *addr = save;
5 z- [* i7 R) C3 P" M3 F& b             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {0 P; q! P* @# q
                     addr  = base + cnt;
% A9 }; U9 o2 O& N  K                      sync ();
( c4 B5 D! _5 P  w+ w8 g                      *addr = save[--i];
. ^" {$ w' H8 w; x             }% Z: m$ S. [" i  j) U' i/ [
            return (0);0 t. i/ b% B# G: c8 u6 V
      }5 ~; X/ n+ e( j) G

7 m! h$ x9 a& y( b. v0 V! n" Z) w0 Y       for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {' k& T  y, T9 N/ M
            addr = base + cnt;       /* pointer arith! */, P. g! \3 \5 x0 K" S% f5 W+ }8 {: J/ e
            val = *addr;3 B. p" d/ z% I
            *addr = save[--i];: Y! k: l  g7 G! i
            if (val != ~cnt) {
; g0 Q& \! R9 T  v                      size = cnt * sizeof (long);
% N; d' o- d  a  \- }2 m( R                      /* Restore the original data before leaving the function.
: s8 ~6 ~( T" x# m0 S8 |                      */* c! o1 B  V5 W6 O
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
3 Q! j- h$ s2 |: b4 K& A                               addr  = base + cnt;
3 X$ D0 u$ g5 Q+ o$ U0 r- T- y# [                               *addr = save[--i];2 X& F" U: I" {+ g& a2 \. m7 t/ B* @
                     }
% E& K" A6 ]: _- T                      return (size);9 u+ }' G9 |  U$ y' y% T4 p
            }& b( v6 p+ c; L" G9 R
      }1 T$ p5 T0 F! c, I$ V3 b" |
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      return (maxsize);( N6 t) D8 m! c$ l
}8 Z8 Z# B4 [. ]! R, Z5 E
int dram_init(void)8 K7 u. n. ]9 U4 U* E, J# M- {
{
  O5 v/ A1 [3 D% }       /* dram_init must store complete ramsize in gd->ram_size */) Z) C  u: O' w/ X$ A
      gd->ram_size = get_ram_size(5 D" |" l6 h+ t) S; X6 j
                     (void *)CONFIG_SYS_SDRAM_BASE,+ W; ?0 e8 `' E
                     CONFIG_MAX_RAM_BANK_SIZE);$ M4 d. Z% _5 x- D) R
      return 0;! z( [1 |8 \" z7 B5 i- j3 L
}) M0 z: D) @) p- K1 l2 o
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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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