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;/ q) B  ~  R. V- |( {* z( G- y0 t+ Y
      sync ();- H  h0 H! Z5 n6 w5 B4 [: t* N8 ]
      *addr = 0;
0 _; \0 R: n2 ?0 {" F8 D8 |' H( k, E8 s/ d+ ~/ C- V
      sync ();
0 c% k2 @& L) I( G: t) F) C+ ]; f       if ((val = *addr) != 0) {
+ ^1 D* n% l6 K" m6 c% l- U             /* Restore the original data before leaving the function.; P$ x% O: |7 S0 [1 o1 h4 v+ Z
               */. i1 ]2 q$ D% q
            sync ();6 S% }+ m" x, _" ?) V# |4 T
            *addr = save;
6 b- e! J& m) U& @) y( g             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
+ d; O- Z3 g# O9 ^9 i                      addr  = base + cnt;
5 ?+ d& T8 |5 H7 f% s                      sync ();' v4 V$ C5 }  o# G9 H4 X4 _- b
                     *addr = save[--i];% P, g9 n+ e! F. r; h: i
            }; o& y4 a  v" g  P' s
            return (0);
& o- L& p: R$ N# X       }" s, Q( U7 l2 b7 G- e3 D' Y' A9 J
5 ^* j. F- Y0 K7 u4 l- o2 U
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {  Z* P/ k! d0 t) i
            addr = base + cnt;       /* pointer arith! */
' B. R- c$ K$ h. @. l6 J             val = *addr;
( v# W5 p* D3 q4 l  d             *addr = save[--i];# X' ^+ s1 E7 j3 u) [4 i
            if (val != ~cnt) {  G( ]7 I: s  [" r& Z9 @
                     size = cnt * sizeof (long);
2 _# r" I1 j- r3 \3 _                      /* Restore the original data before leaving the function.% h( ]/ X; ]7 m+ [
                     */- }  j$ a4 {( @1 `$ K9 Y: I) j
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {$ f. P0 c6 b; v' n4 R
                              addr  = base + cnt;1 b8 m# ~/ u& V6 L9 p- j8 K
                              *addr = save[--i];
0 b- l0 |7 i. s" e                      }' ~4 C/ u( C, o5 p3 D- d
                     return (size);
6 o8 s8 b. K1 i8 S+ }, T; l             }
; l+ M( r9 d& C: u9 @( ~- b       }7 _4 q: C7 l# T

( ?: r& D# V- N4 n       return (maxsize);( ~! V, b( Q* ~8 Z: C
}
! i; ]5 X) F" H& zint dram_init(void)
: {2 m. n- A' R9 l{* |  @+ `- \% f
      /* dram_init must store complete ramsize in gd->ram_size */
: C# T8 b& l. {# w$ C2 C       gd->ram_size = get_ram_size(8 z' H: M0 R0 M  [5 C
                     (void *)CONFIG_SYS_SDRAM_BASE,9 f, m8 t, q7 O( |$ X* A/ B1 h
                     CONFIG_MAX_RAM_BANK_SIZE);$ x2 k5 l. q) k: n' v
      return 0;
& O9 M. F$ I. T% B3 {# l% N* o2 k}
- o6 a- U: f8 G) B
/ g; h5 h% Z+ ?5 `% B9 o
  J# O1 w: M" z, a; Z6 s1 k8 g% P7 j- O4 K+ k$ a# e
' [- c! p5 C/ A9 R0 l* }" |* Q
FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！7 ~; o; `$ s' b0 Q

" P% L* F* V* J; l; R8 W: X# Q7 y' D8 X% r

		自动登录	找回密码
密码			立即注册