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;: b8 w+ E& Y. a2 ?$ p
      sync ();
  _% c" r8 c& S4 V3 F, u       *addr = 0;, }8 b) Y; @6 j/ ]+ K

$ e' m8 a4 |/ A       sync ();
& E+ f, L5 @: T$ c; E) V/ U       if ((val = *addr) != 0) {$ D( O9 x- F  n$ r/ B  \) A
            /* Restore the original data before leaving the function.0 P: c4 H! k! ]7 ^) y
               */( E) E; i' P  e" {* u+ ^
            sync ();
6 q4 J: c3 a1 Q4 r' \1 d8 I' ^             *addr = save;
7 |8 Q, ^) W$ U/ \# K' S- r             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
  _& N/ L" l3 b# |2 @+ ]& l) g                      addr  = base + cnt;
. M/ X8 k% k$ L5 z5 l                      sync ();8 J3 Q; X2 W& Z
                     *addr = save[--i];0 Q- ]$ w/ Q6 ^
            }/ x2 B* K- u& [" `# J  q
            return (0);
2 U# @+ Q( V  L% b: ]. t       }
  ~5 C- r: }- \1 t% E, z3 \% j  K6 r. h+ P2 @
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
. i( ]( A6 @4 b% W" S$ V             addr = base + cnt;       /* pointer arith! */3 q9 B3 ~1 g7 ^* G) }
            val = *addr;
  G0 A4 w3 T# ~4 l* ]             *addr = save[--i];9 M# e4 f9 U; o+ G1 |
            if (val != ~cnt) {
( S& ^# d4 l3 R8 n7 R8 k: m                      size = cnt * sizeof (long);/ N- N  S4 S7 g
                     /* Restore the original data before leaving the function.
& d# [  d* Y4 h! N+ e! B                      */( F5 N1 ]8 M; n& u- f+ K
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {6 K  G6 F1 l$ V- g6 q' ], }+ S: g
                              addr  = base + cnt;
% y4 j0 _$ R# p  o! e+ U! q                               *addr = save[--i];3 s( Q9 k$ f6 J) c5 T
                     }
1 A8 L- b' E9 b* z# r                      return (size);8 z+ h* e5 _  W7 Z' }
            }
; Q# d; z: T* p, e8 |       }" N* S3 `" k$ x& Z. `4 Y* {5 j
$ D' E' W4 X/ ~& i+ D4 D% X+ r
      return (maxsize);* \5 [! c# e1 ]) h
}
' u' \" o% q6 f% i0 [- ?int dram_init(void)
  G; p4 U4 j/ L" Z, B{
5 C, k1 X, V6 i2 y       /* dram_init must store complete ramsize in gd->ram_size */
2 v. h; G9 H2 ^+ w& d8 ]4 u7 Q( q2 ~. M       gd->ram_size = get_ram_size(  G; s3 _) `! b$ P! s) }& Q3 M7 m
                     (void *)CONFIG_SYS_SDRAM_BASE,
3 I$ @: V) I2 e& Z/ J                      CONFIG_MAX_RAM_BANK_SIZE);4 n# ?* J1 C  V- k6 r4 W
      return 0;4 N2 z0 G0 }; l5 u% j; |
}) u$ v# Q7 G6 D0 V9 z# r# g
  H/ Y* d+ q8 [% O! t- e  r* T

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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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