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;
. B- f4 A, X' |; ^, r' V       sync ();/ U6 i7 o5 X; s* k1 ^- g4 K
      *addr = 0;( M2 m: S1 m. a1 u! t9 I7 Y) U) b
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      sync ();5 C/ d' ]4 ~0 q5 L2 L* N
      if ((val = *addr) != 0) {, ]: g! ?# M7 h! h0 {5 a1 z0 v& c
            /* Restore the original data before leaving the function.
& c% ]1 k% O0 U; C+ _9 x                */
4 l* o$ ?* S1 O0 v' g$ r- X0 @8 ^             sync ();
/ L/ I. S" {2 a7 f. j  [- y. w, n             *addr = save;
* L7 w; d! O8 D" K7 \             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
& W9 ~5 T+ g) N                      addr  = base + cnt;
, o$ U3 ?/ A# a; ]( p                      sync ();: f( ~9 k) d* s2 T! a
                     *addr = save[--i];. W1 P) T/ _% _0 {0 w# G
            }" F) e9 r1 ~' v3 f( u
            return (0);  @; T+ {$ r1 j6 Q, B2 \+ I
      }. ?9 s$ G  U8 w1 i7 R
  t+ u. {" b, y
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {* Z1 m! P3 w; M! J2 b9 I
            addr = base + cnt;       /* pointer arith! */
5 X0 f/ m+ k2 ]7 i' X4 P             val = *addr;& q7 c6 q) z  X1 W) k& f3 C
            *addr = save[--i];9 c, G% S- f# S- @$ H' C0 x: x8 m
            if (val != ~cnt) {5 X2 {7 _$ V! R7 P2 S- I/ h
                     size = cnt * sizeof (long);
; ^+ G7 s, b, I" \* Y                      /* Restore the original data before leaving the function.8 _1 j5 v8 `/ `: B1 k+ H1 `
                     */- L" m2 V4 F8 M' Y$ T
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
8 Z. i. _5 _' ?5 a" S1 o                               addr  = base + cnt;; P$ B# u! b% X* I/ D# G4 V2 F
                              *addr = save[--i];
8 o' O+ n, k0 I+ R7 R                      }
' E; o% A/ G' l% `; }, o" H* \- ?                      return (size);& s  v3 ]8 R- W  u8 q) M! o# j" G
            }
. [% j/ o( t7 C2 _- [# d% B       }. s  a( l" j" w0 b0 O0 C

4 K' T! M) b6 F, v- |0 c2 X       return (maxsize);1 v  h+ a8 v$ h6 [" H& ^2 T. r9 m* X
}
; x- f! V; ~- ?8 F* n, Y3 |int dram_init(void). K  K! C4 i: y: |# H# |
{
; f6 S# |: B# i0 d       /* dram_init must store complete ramsize in gd->ram_size */* K* b! F- ]9 M5 P1 V7 \9 h/ v2 A: ^/ Y
      gd->ram_size = get_ram_size(  k  I; o& ~( F# x2 Z" X
                     (void *)CONFIG_SYS_SDRAM_BASE,
7 y% ^6 q% `2 \5 Z6 T/ u- M% {                      CONFIG_MAX_RAM_BANK_SIZE);
( {& k3 N+ Q" a) e' o( ]       return 0;" {$ \2 Y$ {7 X
}
0 ?: k% H5 k5 [" f6 \" Y" C* v7 Y  `* b3 a
6 n. B& P- s% [' G; D  X* Y
% C) j# y& Y! ]3 u% y( j( V
2 A4 b% N/ S7 b7 ?
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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