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;
9 ^$ V  b0 M0 G$ v& ?6 ~6 ~% v, u6 T       sync ();
, d; |. \8 j2 S% D       *addr = 0;7 u' o: B; C: I* c/ R
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      sync ();: _2 w) j- q" y0 u
      if ((val = *addr) != 0) {1 d* `& P' h  {/ H6 O3 }
            /* Restore the original data before leaving the function.
8 B+ s  z3 H9 F0 q" H4 B                */
* T$ v  o7 u5 l6 s5 z: L  t1 B             sync ();
6 i* v0 i0 _, D' a             *addr = save;
0 _+ P$ p" ?. |9 N             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {- h! B. `: @3 A& s; a8 S
                     addr  = base + cnt;
8 A: V" Z& W8 J8 `5 q" F" g                      sync ();
" L! Q3 G; v/ X: r$ s( f! Y                      *addr = save[--i];6 u7 @) ?6 J  t
            }
8 ~9 }2 w: e$ b             return (0);
) D$ r  D& g0 Z% k3 S       }' L0 v7 m, K: n/ b) d; E

$ p; p9 K1 k) Y, Q$ g/ D       for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {- V5 p+ Y% C" h$ i. w
            addr = base + cnt;       /* pointer arith! */
2 U" I# J+ |! C' P5 T) l6 ]7 z             val = *addr;5 y9 y0 D! S6 S8 K8 k' B9 ]
            *addr = save[--i];% O- T3 f' x: h3 |. ^; H5 v0 X
            if (val != ~cnt) {' c) U# y& V8 T7 C  O1 z
                     size = cnt * sizeof (long);
+ m. g, d: ]9 a* o                      /* Restore the original data before leaving the function.
* P+ E  n! X. c$ o  L2 N+ o# I$ ~                      */
5 k4 i  I+ n. H% v3 Q! ~$ f# E                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {( y1 k0 L- i  r- h$ H
                              addr  = base + cnt;2 ~$ x/ J" }$ d. \% U) w
                              *addr = save[--i];* |9 R! S: g: N9 G& j9 x6 Y
                     }; b$ q) z3 f- V8 E
                     return (size);
! n, }9 R* S% R, f             }% J# ~. C# h9 l1 v0 e0 ?3 o6 o
      }$ d+ H3 A+ V2 R! y: l9 J
. @# v. Z1 k+ R: o0 u5 I9 u
      return (maxsize);  @' f7 \% Q3 e* {2 f, y
}
" w+ s- X7 c+ S$ H1 s/ ?" Lint dram_init(void)/ S% Q8 Q5 {: ]$ R, r) |- V
{' U5 ~2 ?" V' J% N3 q4 K5 b
      /* dram_init must store complete ramsize in gd->ram_size */
( A$ t9 R& u6 V$ i! E6 S       gd->ram_size = get_ram_size(
) G8 Z# ^7 a5 z% h                      (void *)CONFIG_SYS_SDRAM_BASE,& B4 M7 j6 y% w
                     CONFIG_MAX_RAM_BANK_SIZE);) G$ Q$ ]$ I* E$ Z5 Y9 U
      return 0;
3 {$ Y) X$ I" J7 s: y9 j0 Y}
' H& w/ \* h" V1 f3 I' z' Q4 i0 p' s* g  Z. U/ K
. o  R& l0 v6 E4 `! A1 e2 n
4 y$ _! j$ V( t9 q$ g) E
3 N  L' n( C! H3 }
FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！0 p2 H2 ^( R. [4 b; S9 [. b

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