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;7 S& l+ k7 r" f1 b9 @" _: u  S
      sync ();7 h7 |8 U! D; A" ?$ D. w- l
      *addr = 0;8 a, W" x/ ~6 U! G$ ]0 r

- Q8 y- J, d$ E- V0 j  J       sync ();
! X+ ~$ C( q! _  G7 B. |' d+ G7 U       if ((val = *addr) != 0) {' v4 m1 @/ `5 [9 k2 S' g
            /* Restore the original data before leaving the function.; ~- A, d$ p6 B) J
               */, [7 Z1 j0 R7 z3 Q8 X' l& ~
            sync ();
% m( G; M( V4 S+ Y1 E' o' r             *addr = save;
3 y3 h- m4 B9 p- E             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
# L; j) `6 r# |3 Q$ E: W  T% j                      addr  = base + cnt;" j" d! `1 J& p$ t
                     sync ();
" `# H  @! U  v6 @: ^. a4 }) C( c                      *addr = save[--i];
* D+ F* {6 ^3 Z8 \             }
; j. r1 r6 t# \  Z             return (0);9 K; ~$ n  T# i
      }' }" F/ s0 R6 q, g/ I
; I; `  l! q0 d& g! P- d
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {, p/ P0 S6 D" a: [6 I
            addr = base + cnt;       /* pointer arith! */& u; t% D' j! @" t$ n/ Q
            val = *addr;
$ `- N8 ~+ z" P: O             *addr = save[--i];
7 Q; a% W/ P& n% ^, C             if (val != ~cnt) {
6 ]7 W1 [. e+ {. x) r" ^7 S  E                      size = cnt * sizeof (long);% P5 ?% |! c: W/ E1 q+ q/ S! J
                     /* Restore the original data before leaving the function.
1 a6 T* h, I" ~, z                      */$ F6 l8 Y$ w5 d+ i& G
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {6 |! l+ ]$ C4 {. p4 B6 v: n# m
                              addr  = base + cnt;# J& O& w/ _9 @% \% D
                              *addr = save[--i];$ n% s: z- O* ]+ r$ N6 U
                     }5 u1 _# \1 f9 E4 b
                     return (size);* A: g8 h4 H4 W- b- M5 H) z
            }4 E1 D. r* s) @- P0 }. k3 T
      }* T/ o' v3 L8 F
+ @5 O9 L% L4 L# I/ r( b2 |/ t5 v
      return (maxsize);" v- X6 L: M5 B( i+ I
}  z( s3 n( I; v+ X
int dram_init(void)
" r/ M! f- n- [" V5 h% Z  i0 A2 p1 g{3 M2 f8 j4 J+ k+ h: B  j4 B
      /* dram_init must store complete ramsize in gd->ram_size */
9 r4 g: B  j: K) x9 x       gd->ram_size = get_ram_size(6 o& J4 F. B8 F0 m# r
                     (void *)CONFIG_SYS_SDRAM_BASE,. y5 }4 u) R4 S& }, g
                     CONFIG_MAX_RAM_BANK_SIZE);
/ v4 T7 F/ I1 p. |. C       return 0;
- K5 Q! S, {/ }+ U6 e! E}* m" |5 y/ C; q. i) {! w! G  p
( i$ ^3 \8 J4 v

. ?: l/ `% Q, O( H9 G* {# u. ^4 Q$ E; z; e) j' O+ W. @- p" k
2 e( s, {8 s. }: |
FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！) T& \; O; w7 Q) h
( |0 b  p5 T) i1 G: R) U  }! t6 `
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