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;
. Z2 y4 c2 s2 X/ l- ?2 x( n       sync ();6 N/ }: Q- E0 N5 @; f+ F! ]. A4 E
      *addr = 0;6 ?$ C. K+ F1 p; h
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      sync ();0 B/ u9 V8 `+ d. |+ m7 k7 ^
      if ((val = *addr) != 0) {3 U/ G3 k. N/ ^- j* c: V% c+ K$ L
            /* Restore the original data before leaving the function./ E7 p( R) L* a! A
               *// ?7 E7 U5 B% `! o6 g& |" h  }0 p
            sync ();! L6 C8 L4 ~& M( s5 L; S
            *addr = save;' k1 s3 N, d$ P$ ?) D2 c; |0 \& {9 V
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
& @- _" h: H% w" q5 E) P                      addr  = base + cnt;. O5 |9 h0 R; x/ o5 K& q
                     sync ();/ Y2 ~. b0 ]% K3 m% B
                     *addr = save[--i];7 V+ f2 m) N& I9 J1 e% M8 a; @
            }
( f- q5 X* {/ H: ?$ I             return (0);
/ `: M6 Z3 \( g- e2 Q3 x       }
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      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
+ h: z- C) A) b5 t             addr = base + cnt;       /* pointer arith! */2 n) ]0 T3 m( E. P# k
            val = *addr;
$ L& Q: s" E* u6 z) S" j- ?             *addr = save[--i];# H; s3 [' v5 A4 a; z5 M
            if (val != ~cnt) {
! {$ r# T$ l5 r' g& |) I                      size = cnt * sizeof (long);
2 e/ [' c% C5 G, w                      /* Restore the original data before leaving the function.+ ^. w4 s( x  @9 ]
                     */& u. i( i: J5 ?: W- e! s, D
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
; E. i$ _+ O8 o9 i" S' o8 t                               addr  = base + cnt;
3 N2 w. z4 q; h( }3 U                               *addr = save[--i];5 N+ x2 ^6 i7 S! ?. Z% P  H8 z
                     }
. y( r# h, w$ L2 D! ^                      return (size);& N* R- _* V: o: j% R% A  f6 r  W; Q
            }2 g8 f) k5 ]/ ~7 Q
      }
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* @/ b! x( ?# v& B6 D3 i       return (maxsize);: Y7 g; P! J$ @  Q; Y
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int dram_init(void)! |; ~4 w2 Z- c+ h1 R0 l
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      /* dram_init must store complete ramsize in gd->ram_size */
& ^) M( ^8 e; X- h: p       gd->ram_size = get_ram_size(
5 `- k3 O2 q1 F8 E: [                      (void *)CONFIG_SYS_SDRAM_BASE,. d$ q  n2 z1 I
                     CONFIG_MAX_RAM_BANK_SIZE);2 I3 H2 Q( e: e
      return 0;/ k1 i; N2 W' }4 g3 u; G
}
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2 v2 X) Y$ T: I' I! o: BFLASH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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