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 I+ P, m  I6 @9 ?1 C7 e" B
      sync ();
9 j) }# m! i0 F9 i& P: i0 K/ E       *addr = 0;6 A9 G$ [  p, H
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      sync ();4 b  |) T/ V5 n6 P, i7 t% `
      if ((val = *addr) != 0) {8 d4 b0 E& i) v$ D+ W/ o2 Z1 p
            /* Restore the original data before leaving the function.7 E) L9 M9 w& w4 h! w
               */- `4 ^) C' f7 l8 k* ?+ S4 L
            sync ();
# J3 v( g0 B% s             *addr = save;6 Y/ u+ G. ~  {, X# J# O
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
0 b! q( d5 K7 Q. a& d: M+ \                      addr  = base + cnt;0 v  Y0 O  ~" o; `+ e
                     sync ();
+ |  g; @- }9 j. a# @6 M8 t* R! q                      *addr = save[--i];2 \: j% \! j2 Q1 j: T& \0 E7 e- H
            }
& M# Q9 c: [$ t             return (0);
" g; {6 y: a9 V" i/ k       }  B" v4 {, ?! ~" f' M+ W; ?. \* y8 s
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      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {2 e) w; S; t6 }
            addr = base + cnt;       /* pointer arith! */
; w0 @3 P5 ~/ `5 E2 d! F+ B& Y             val = *addr;
7 S( L- R6 O3 O$ x, R  L  Y( G/ e             *addr = save[--i];3 F6 T, Q, ~- p- A
            if (val != ~cnt) {
& A& W2 j) z0 T6 E9 r- L! _                      size = cnt * sizeof (long);9 E- n6 g" p  h
                     /* Restore the original data before leaving the function.
' @' J* x( d: {! `, p                      */
( D+ l" M( z0 [/ ~8 U8 o" \! E5 N                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
# ]4 p& L  m) a                               addr  = base + cnt;
+ B6 h/ m# w$ E7 |0 F                               *addr = save[--i];/ N( J  I* [+ Y# [8 I: h/ Y
                     }
: q3 s5 P& C: K% N# {! U; _                      return (size);
: M- y' `/ |5 R4 |$ R0 @             }- }* D: n" i" g9 ]3 ^5 C; {
      }0 a/ e4 F2 u5 y& U7 t& ^: y
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      return (maxsize);3 t) y+ D2 S5 J' E7 o2 E
}7 ^+ z" N2 G6 M. E. R! F, c3 z
int dram_init(void)+ W) Y: E5 q5 f8 E  k& w
{$ Z" }0 f% @! J* }4 S# E
      /* dram_init must store complete ramsize in gd->ram_size */
/ ]; w# ~" u( E7 j1 B; R       gd->ram_size = get_ram_size(
6 `& i2 M/ @/ x6 T% }2 q2 V                      (void *)CONFIG_SYS_SDRAM_BASE,% o/ b, B5 W/ v& [! k
                     CONFIG_MAX_RAM_BANK_SIZE);8 Z( U0 c5 C) b" w7 Z
      return 0;
* s* Q, J" N- w! J; F}
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  C  |& g9 l. A6 l! \, h% MFLASH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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