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; q. i" V' z       sync ();+ S& E$ \# E. V
      *addr = 0;
" w: M  J$ M/ }# y& w( e* k$ D$ l& @. l  ^0 |: `: h; ~+ F
      sync ();1 B: d5 W+ @1 A5 R
      if ((val = *addr) != 0) {
# ^' [' Y: |. j             /* Restore the original data before leaving the function.$ z- q  W  b2 ]% I- K  h6 `
               */, X* A( C) E1 C2 V/ S3 |5 \
            sync ();3 p* e, @1 _, o, r4 l
            *addr = save;
; i! b2 _) O( ]             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {0 ~$ E( ~! l5 f& ?5 W
                     addr  = base + cnt;
8 ]9 s# R; y5 z% {                      sync ();" Y" ]7 Q" B6 a, I' t$ h
                     *addr = save[--i];
, h- F. [3 Q% f% V% p" g9 a+ y             }
4 f5 K; h7 f# Z% E) W             return (0);
4 [9 I: D1 b' T( V5 f2 n       }9 z2 g+ F* {3 M, m3 ?" s' C% g
3 O* g/ d- \- M# H: z' x2 y
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {: C; B/ I$ o( o$ f
            addr = base + cnt;       /* pointer arith! */& d9 I4 O5 h  V" E/ J+ T5 T
            val = *addr;/ O) S$ [/ @. t/ `- L3 [8 \* F
            *addr = save[--i];# M3 e, ]2 G) B7 E- ?& t* M
            if (val != ~cnt) {
8 \% J+ Z9 K+ E3 z! a3 {                      size = cnt * sizeof (long);9 ]; E  {4 M) T0 Y
                     /* Restore the original data before leaving the function.
* z5 L; W; I3 H* N: A                      */* x- E8 `! K0 F+ `& k; U. B
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
! l! s, ]& V, n. F8 Z$ }; `                               addr  = base + cnt;
  \; m& @1 i4 X6 a* a4 i, \                               *addr = save[--i];& w$ H+ I, y5 a8 ~6 d; H) |
                     }7 F$ F. V3 y- G, i: Y
                     return (size);* S  z$ o+ h6 `8 L! v" Q- v4 S
            }* D+ ]& m6 Z+ ?  P. R% \
      }6 q; [+ e* v8 s: b+ [

2 X0 Q5 l2 r3 q       return (maxsize);
' S" C( }/ ]  h0 j}  P3 x( f- o7 j
int dram_init(void)# ?2 f# s$ A+ t& r. ^! s
{, A. W( q0 K% k/ W6 j4 y
      /* dram_init must store complete ramsize in gd->ram_size */
# l9 R9 o* u, v% b       gd->ram_size = get_ram_size($ |- P' h( B; S* O+ s
                     (void *)CONFIG_SYS_SDRAM_BASE,
6 d* c' p6 C- ~" x: z$ M& f                      CONFIG_MAX_RAM_BANK_SIZE);
& C  ?5 y# B& I       return 0;# T) s! H% [' V' V0 D8 O
}/ Y2 q0 j7 T0 p! E

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# r  d' h8 S3 P- H& r* [1 {  @+ E& I4 w; C. c6 |
FLASH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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