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;
# G3 ]& s4 P2 {5 Q; Z       sync ();3 b# Y% J8 ~/ _9 O2 ~1 [# h
      *addr = 0;
* U9 H4 C3 |) X  k: I+ V, E8 q" @. l
      sync ();  t3 \/ e. f$ c# p
      if ((val = *addr) != 0) {# g( ^2 Q& _' X; q# c# h
            /* Restore the original data before leaving the function.8 Y6 {1 ~3 N9 [  k0 m4 z, N& x) n/ [
               */
: ^+ x! }& H* T: P! E. J             sync ();. z, H" ]% g% r% Q- S
            *addr = save;  y9 v0 |& ?' Y6 O0 g; I( i1 S
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {1 _% C1 h, h" Z$ S8 O, P, J9 U: V
                     addr  = base + cnt;
% i9 T" x! m2 C6 H: ^, I) r                      sync ();
2 B( i, X% Y3 h; s- b2 T- F! V                      *addr = save[--i];" A! {! v1 W% S  G' E
            }3 L- g, S( I" T
            return (0);1 T+ x! S  P# T" @, n! |7 s
      }
. U4 C( M7 `9 E) R" R! m2 W! s" }+ C. ]& [3 F% D- s- T! M7 Z
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {# U% O' x6 z* q4 A" ^+ R$ [, y5 [
            addr = base + cnt;       /* pointer arith! */
$ H$ E9 m9 W% r- q             val = *addr;9 ?( B( ^# C( a6 o' u+ Z
            *addr = save[--i];
" E: O" F' a( w1 b# _. b* T: F             if (val != ~cnt) {
$ F3 _  r  p2 N9 e) o& O                      size = cnt * sizeof (long);
; U7 `+ _: n5 r2 b6 _                      /* Restore the original data before leaving the function.
0 \& b6 W+ \  {, q$ t                      */  R1 @% I, Z9 i. ?
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {/ E9 p7 e- U* w* o
                              addr  = base + cnt;; b+ u5 \( _; D) ^( _
                              *addr = save[--i];1 u& z5 @( Q" r  n" |6 K3 X0 n. O. m
                     }# t8 E/ t5 v: x8 I! S/ j0 B
                     return (size);/ D9 x& E8 }5 W& G" {7 t% s& t, q
            }
, w: ]' }1 l- }3 X4 g       }
; \/ S( }2 [- x8 ^; f6 s& J* w( T; G( N
      return (maxsize);
& @8 C, ?, d6 q}
) H; k0 p1 v( M3 M# Q' |3 yint dram_init(void)9 _6 _) ?# j8 Z$ b$ `4 B
{. M8 c) z( U0 K" a1 w; A
      /* dram_init must store complete ramsize in gd->ram_size */9 R6 j* ^, x* p" |
      gd->ram_size = get_ram_size(9 i) E0 ~* `7 @0 D
                     (void *)CONFIG_SYS_SDRAM_BASE,
0 _* `& b& N9 E+ _* [/ t' ^                      CONFIG_MAX_RAM_BANK_SIZE);) z9 G3 W7 r9 T+ |' z
      return 0;0 d9 x. s5 f- V" a* Y% A' Y/ Q8 _
}
, w9 ~2 l0 i$ X: d, E+ U6 s2 ~$ ?* q; R
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% v; t# w, d# i  @2 a4 k5 V
$ n# V1 f: `1 Q0 l/ n2 n0 NFLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！6 h: R  Q% y6 L5 {  D6 D

% U$ q8 r3 q% T/ s/ S' }
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