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;# _6 V( h# {8 ^9 l* W, ]
      sync ();
5 u9 Z+ x+ Q  r& a' ^2 j       *addr = 0;
  l. @+ h- d6 P5 c3 F3 Z
# @  }/ n7 L4 Z' M5 F       sync ();# S; m# Y0 s! ?; Z2 @
      if ((val = *addr) != 0) {
# ]3 i, t7 ~# d* E! n- O             /* Restore the original data before leaving the function.0 H9 E4 ?% j$ D9 N4 `8 u4 m. a
               */& a& W! G% s4 _( y6 v2 D$ k
            sync ();
' o0 K0 M' u4 s( F1 h* p- X             *addr = save;
0 `% s) m: q& ~  S6 ?             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {% B$ K7 }' D- Q) m/ C2 V0 b/ @
                     addr  = base + cnt;/ V* }4 K2 G9 w: A
                     sync ();
' p& i+ x& r! k4 I- T6 a  Y                      *addr = save[--i];3 e9 z8 X9 F. ]+ q& [
            }
7 q# v9 o" d5 t             return (0);+ k7 B2 }: f/ c& d* t5 X
      }0 z: Q1 H9 ]7 X- q6 w/ ]7 T) O

6 Q8 Q) [* K8 K! Q! ?       for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {  J6 }9 I, z: @9 H  G& W2 T
            addr = base + cnt;       /* pointer arith! */
* T: u% \8 u* T+ l- s- t% X2 R! v, [             val = *addr;9 P- v* V3 a) Q* p. G2 V
            *addr = save[--i];
' u* y' }- D8 Y; b" f             if (val != ~cnt) {
5 \) B7 J( w( ?# }4 E                      size = cnt * sizeof (long);, r0 ]  O1 E8 h- d; q
                     /* Restore the original data before leaving the function., x) T* U/ [  z4 {; v
                     */) J$ L' r. W# |. B* Z
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {; e5 l" A1 S5 n' q6 ^, Q
                              addr  = base + cnt;: e8 d& D6 c  W( O$ `' D" \! T
                              *addr = save[--i];
: T) F6 a9 a& p) X2 C% I! P                      }
! D; H" V; }/ ~+ T                      return (size);
5 p8 h; z' B& O: i0 h' |3 X9 e             }, B; C* V: m# d. M& v
      }; O4 d; I1 ?( ?* D$ f
! {5 C4 H+ U, E3 c* a
      return (maxsize);2 @) ~, G  \0 E! ^; @$ p1 A0 u
}) ?! O) V' T* y2 U; E8 E
int dram_init(void): f  {2 x" A: t# P- K
{9 C' Z) s% l! d& K; C* t7 z: B9 `
      /* dram_init must store complete ramsize in gd->ram_size */3 [9 V" q- v/ _. ?$ s. o  d. e; ]
      gd->ram_size = get_ram_size(3 T4 t7 |" w9 C+ F! o
                     (void *)CONFIG_SYS_SDRAM_BASE,
& U0 C, y+ L/ c5 j' S. I                      CONFIG_MAX_RAM_BANK_SIZE);
; J' x% v/ o4 u& z7 G5 Y  }       return 0;, l/ E- E7 e- [$ g8 G
}1 @& V( U& O! b. Y

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9 z8 K+ D. l# Y6 H7 _  D# k/ o/ g0 \% ^9 A
FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！& o* y1 O- w! @, J0 U/ ^
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