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;- T# U( z. i% N0 [1 v) `/ L
      sync ();
4 C. S8 {2 J* ^+ P. w8 B: _       *addr = 0;0 x9 n$ P! _% N& |$ y( x* t

. U0 J4 f3 M$ F- i- n. @  N       sync ();, K4 _3 V3 {4 B4 c* H
      if ((val = *addr) != 0) {% G1 C4 J& ?/ `& h, w2 X) Q
            /* Restore the original data before leaving the function.
, h$ v/ L2 c; w3 T& {                */8 E1 u4 V; A7 A7 h( U& w0 w9 e8 X  w
            sync ();1 {) C! [' l6 M; f: X& ~& X$ t
            *addr = save;5 ~2 d8 b% L' X- L! L3 f! E/ N8 G
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {4 p& ~6 w* ^) I% @6 Y1 Q, U9 s
                     addr  = base + cnt;
8 z, n5 z; P% G& u" ]9 ?4 S; U                      sync ();$ u3 I/ B6 r$ v  L+ A! r
                     *addr = save[--i];, [/ u: c7 a! ?
            }6 J7 ~% w$ L5 A( z3 |
            return (0);+ o$ z$ w: [# L
      }
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      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
! m' z" D7 v- n6 J2 H  C. v             addr = base + cnt;       /* pointer arith! */
. S. T3 N+ I; D5 H             val = *addr;5 o$ I  {8 f0 V3 o! A* X* a
            *addr = save[--i];
5 K3 b, A: Y; X  x             if (val != ~cnt) {3 G* g: r7 ~8 s
                     size = cnt * sizeof (long);
1 P( d9 P) @* t# O- c                      /* Restore the original data before leaving the function.% C' L9 a: W, j
                     */
. C. h8 k$ q8 n2 E" W; o                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
) k# x4 d& B, S; ^/ L" B9 ?                               addr  = base + cnt;
  j' q4 S1 }8 y9 i/ Z% Z                               *addr = save[--i];/ H! K! X0 j$ A% D
                     }
2 \5 T( v; W5 _! j4 t                      return (size);
0 e! c* s3 a$ }5 t9 K9 W             }
" E0 X2 K' c. e/ h5 y       }
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      return (maxsize);9 E! w& C" L# v2 n2 _2 D8 y* R
}+ C( W( P2 T) j0 N8 f: T$ L3 a
int dram_init(void)
/ B" @7 Q' Y! A* l! d{
( f) ?/ O6 k6 x% i, V       /* dram_init must store complete ramsize in gd->ram_size */
) j, X6 ?2 `; D2 P       gd->ram_size = get_ram_size(1 W- D3 C" i" N( d1 F2 I$ J6 E; ]
                     (void *)CONFIG_SYS_SDRAM_BASE,% e- T# e7 Y  S: a7 n
                     CONFIG_MAX_RAM_BANK_SIZE);
/ e  l; _+ v- X       return 0;% J$ S& S# u/ H  B! m5 Q9 w
}6 Y0 o; T) _8 X; S, a

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* f# F+ a5 [9 h% U2 l1 P+ C
FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！( u8 |5 r& t# e5 y9 T

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