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;3 }; l) t' B/ c  s
      sync ();+ {) ^* q$ G# R5 `' r
      *addr = 0;+ V+ Y8 d" O9 I) H0 C9 }2 x) {
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      sync ();
# `6 a7 A7 |, n. P0 f5 d' j       if ((val = *addr) != 0) {* e' O" m: }9 _) L
            /* Restore the original data before leaving the function.
& W, O( @- {5 Y+ J: o, l                */
% q$ \, b) F; |* {             sync ();
9 A3 @% F# W$ }0 {. s/ `             *addr = save;
: A1 y8 F2 @4 l0 m: d! T- t             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {2 z1 ]+ i, z5 K
                     addr  = base + cnt;
/ n3 B+ W9 j( w" Z$ n) v- G3 p$ ~                      sync ();
7 c, c: J# Z" i  ~3 s% D* z                      *addr = save[--i];
" t, ~, c6 q: m             }3 q6 N1 {' L' Y6 g4 N* [
            return (0);  K# G9 b; R* {  R# B
      }# X/ |% T$ O' ]1 W# A
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      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {1 @1 D$ l4 n+ W/ `0 S
            addr = base + cnt;       /* pointer arith! */! F' C9 q& x  b. O5 D. o; A( E
            val = *addr;
4 x& W! I: g3 \3 `' ~9 N             *addr = save[--i];" A* o3 E7 [* u1 ?3 v  W) X
            if (val != ~cnt) {; i2 |- ?- V/ C* I4 i
                     size = cnt * sizeof (long);- `. m  h1 n5 V/ g4 P: j
                     /* Restore the original data before leaving the function.5 r) D* t" V% h% M8 y
                     */
* p( d- e) n$ S" z/ x                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {2 o5 t- j$ ]0 F! @# L+ ~$ i
                              addr  = base + cnt;; ?& d! L3 T0 _# o& E: I
                              *addr = save[--i];
3 ]* h" G' y) y1 b- F+ e                      }
. H# F# F- J! \8 B                      return (size);
* G8 H$ h2 j, J/ `8 q3 g             }) j1 g/ p8 @3 Y- t
      }
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6 ]5 t- x" R/ O5 n, ]  g       return (maxsize);8 B9 b1 ~! j4 ^& G5 F4 y
}% b3 ~5 J! G0 G, p
int dram_init(void)0 j* r/ o4 n" m: }  x4 b: K1 V
{% w, D. `; f) @
      /* dram_init must store complete ramsize in gd->ram_size */) h2 q" l  n) h# n# o. N
      gd->ram_size = get_ram_size(+ o1 j) Q6 o6 `, b; B9 P% O( D
                     (void *)CONFIG_SYS_SDRAM_BASE,2 O6 Z1 L- R2 b, j( V+ m. ]* J; g
                     CONFIG_MAX_RAM_BANK_SIZE);9 x- h- m2 }5 v8 M, {* U
      return 0;: Z* N' w. k) e+ p
}4 {! e* s/ \& g# L$ ]

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% i. P4 _7 c' t! q' `: XFLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！' _! b; Y) Z- q  h" s3 g. D# H

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