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;
: J: w$ i6 z6 f6 S0 L: ]       sync ();0 h5 F, a( F% K( B8 \; N) a
      *addr = 0;" y7 W. n$ ]* L; u* j8 [
% T& A( u8 F9 V; x
      sync ();2 |1 a9 d' g8 a/ U
      if ((val = *addr) != 0) {5 U6 O; P" w/ I2 X% ]6 \
            /* Restore the original data before leaving the function.# C5 L$ @, M3 [; C( @7 j! C4 b2 A
               */
% b% ^* b8 G- u8 c7 k7 e( x5 h: ]             sync ();3 ]0 u* G' b1 D% J) L
            *addr = save;
/ y, e6 p8 e. s4 R             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {: D8 Q' b9 ^& z1 D2 X+ t
                     addr  = base + cnt;/ o* m' O5 M8 p: Y
                     sync ();$ K3 d+ ~9 W* l1 j% h
                     *addr = save[--i];
* K. \* g! _4 P' G7 F5 h             }; l! o9 g5 h* T/ c2 g
            return (0);% s; c% `$ s, @: ~. C# u
      }
' J1 W. a$ [. f7 e& c6 I, H. u: u& k# n% A- h7 e
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {: Q' v- S4 N$ ]3 c" O
            addr = base + cnt;       /* pointer arith! */
' l1 _7 l' Y# V( Q( Z% }             val = *addr;. K8 T( e, L9 _2 h3 f
            *addr = save[--i];
/ j) T/ n2 ~$ r% y2 c) P& D( @             if (val != ~cnt) {
# ]! ]9 l  x) o8 p* ]                      size = cnt * sizeof (long);% I8 j/ R# B7 J6 D+ T+ S
                     /* Restore the original data before leaving the function.
" H* v+ `2 U( @2 t* M* d                      */
3 Y( F0 F& [. s+ ]# S; A4 F                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
+ l! G1 a5 A! B# [0 E% ~0 O8 Q) [                               addr  = base + cnt;
! C% x8 o1 R0 \- e, z9 S) _" ~                               *addr = save[--i];
& c+ {! K' f. R8 C& E; h- f  P                      }3 B% P: g1 r5 j2 U, u/ d; G2 O
                     return (size);+ [, {  @5 N7 j4 |
            }
! z8 h' @  _3 I' B4 T       }3 V& G7 I' D* W+ _4 {% M
& f- e+ {) F& B: t; b& A: F# e( i
      return (maxsize);2 r- I1 u5 ^- p7 A  ]+ H" t' }
}9 [3 E& z+ V+ W; c7 ]
int dram_init(void)
% e* i4 @& w! m* U{
; g9 \% m7 R; l( i$ W       /* dram_init must store complete ramsize in gd->ram_size */: M* f" `8 p, d/ T3 L' U
      gd->ram_size = get_ram_size(
+ {5 ^6 I3 p" {" ^                      (void *)CONFIG_SYS_SDRAM_BASE,; Z% L0 W0 ?7 E% n- b$ M- q- _
                     CONFIG_MAX_RAM_BANK_SIZE);) a6 S: E5 X/ l+ x$ Q# i
      return 0;
. g0 M6 ~7 x: F! W  o6 _}
$ u0 S9 i8 N! T3 P4 _! H/ B( D+ T- l  m& W. d* i- m* {

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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！) r6 O6 v8 o) y! \# x7 ~
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