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;
8 T" C& l6 k8 I/ j$ R# C       sync ();: q! c0 t! A5 C7 B% I
      *addr = 0;
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      sync ();
: n7 g9 e+ j8 }7 O% _% }       if ((val = *addr) != 0) {* o, Q  P) w, E3 q1 y! t6 [
            /* Restore the original data before leaving the function.! B8 w' \) `# f$ ~" N/ V
               */- S. x2 ^3 s% k' M1 x
            sync ();
1 h$ S7 j* o8 I6 T             *addr = save;7 U' \& q( L$ G7 ?' \- P' B2 J
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
0 I6 \- h4 I& W+ `  t                      addr  = base + cnt;4 Z6 i: n. T9 ?# Z: y# w
                     sync ();
, i. A. x5 _( O+ J+ E7 x                      *addr = save[--i];
' ~+ _8 C" v5 g4 c. o             }
: k- M1 Q: _4 m8 H* o9 p             return (0);! Y1 \) }- ^0 D1 k4 R4 a
      }
; H2 h+ X; c( Q4 ?1 g$ Q2 ~, u: ?( a+ k, {" C* P
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {( S6 z8 V7 Z' J2 }; u9 d5 e
            addr = base + cnt;       /* pointer arith! */
: _. }$ A3 G) b6 o+ i" Z3 }" O             val = *addr;
$ c2 l- Q8 f9 z5 t2 _             *addr = save[--i];
+ Q1 z  S! N( d3 U7 ?) N5 x" z$ s             if (val != ~cnt) {" P: B& e6 ^7 n+ x1 [: d; X8 I
                     size = cnt * sizeof (long);
% w2 ?" P" T/ j, P9 W/ z6 v2 e' Q                      /* Restore the original data before leaving the function.# E; U* }( N2 r5 Q1 t8 f, \
                     */
; k: i" N+ F. m5 z  A                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
$ R  Y4 M( z7 L7 C' H+ b% C. \+ [                               addr  = base + cnt;& O% N+ G* T. a0 X* T: s
                              *addr = save[--i];8 D5 N- Y9 K- P( N
                     }
! w0 u; }2 n, h+ p6 F! J; G                      return (size);, m5 ]2 T/ h  m
            }
5 H5 D5 t( z3 O9 ^: U% i) J       }
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      return (maxsize);
8 }/ l" l4 [2 `3 @( ?}) H" u6 ^. j4 j1 G1 j
int dram_init(void)
: X6 J$ E% A' N5 |{2 B9 b( J9 y9 B- O, T9 O' o
      /* dram_init must store complete ramsize in gd->ram_size */  H- W  b; `+ b  |8 K7 O% j
      gd->ram_size = get_ram_size(/ e( J1 Z* v' H' @
                     (void *)CONFIG_SYS_SDRAM_BASE,  R3 q* |9 o1 Z  Y7 \& T
                     CONFIG_MAX_RAM_BANK_SIZE);, J7 B9 J! A7 G$ Y0 @
      return 0;5 _, N4 ]5 J# R  j
}. p- N1 `) R' r) r% E
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4 a) ]5 Y0 O" O( ]0 @0 U$ TFLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！5 Q+ ?' s9 L" h" n7 x* U! c
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