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;
5 @4 b7 O+ i! ~3 j( i8 p0 q       sync ();2 ~9 x% n  |* r
      *addr = 0;
2 ~& v2 r1 K6 P; [$ n: _$ C, Q& s. A) Q5 P
      sync ();% C& U8 _' \8 D% S
      if ((val = *addr) != 0) {
' \: v* o" o% \0 }8 j0 ?             /* Restore the original data before leaving the function.
3 ^4 T5 `, m" _. F3 Z                */# ^9 c+ w, T& S9 [8 s. n
            sync ();
7 {1 g1 n: `4 q             *addr = save;$ f8 u% Q# m2 ?" l
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {3 o- _/ c' s: s, v1 Q" F  \
                     addr  = base + cnt;4 u+ j; b0 B* @5 k9 y+ f
                     sync ();  Q* {/ r8 c( k1 H& D. k8 F! K. ]
                     *addr = save[--i];4 \. ~" R' [) ]( k  s3 G. p
            }- ?5 c, S/ M" A+ U2 R1 ~( e
            return (0);+ }: j( A! g* n) v1 k5 c. `
      }
* o4 K1 c6 U. h1 _, U& V4 K) q2 d/ v/ O; P1 ]
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
1 P( V& x( d/ x" g             addr = base + cnt;       /* pointer arith! */. O, g3 G2 L, A2 I+ M- k9 u
            val = *addr;' X2 p6 ?) V' K7 Y1 F
            *addr = save[--i];8 `4 d# H% [1 s; r, Z+ E
            if (val != ~cnt) {
6 q5 z: Z2 G% `8 }7 ]5 G* W                      size = cnt * sizeof (long);0 V/ u8 C- O( R& z0 S) \
                     /* Restore the original data before leaving the function.
4 B3 Y5 \% Y& T  o7 O                      */
& z6 X0 V9 e; c3 v! W                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {5 h; z( N0 a7 ^9 \# n1 Z% V/ }
                              addr  = base + cnt;: K4 D" |* M, \
                              *addr = save[--i];
1 q# Y: U7 {3 [) L" V/ }. c                      }# n" _& r$ Z& Y( @2 h& N8 k
                     return (size);2 t+ ]' z) ?1 H& S, Z/ b6 Q
            }
1 ~# p( q9 A! ]       }( b2 f) A9 T  j9 L

! U& r) u+ f. w. \       return (maxsize);
. J2 I% Q% K& v! I}
) `" ]! |1 P+ x' W2 b: Z) Rint dram_init(void)
# O" i( R2 q0 p# ]{+ L5 U% X* T, h5 s  e3 ^
      /* dram_init must store complete ramsize in gd->ram_size */
2 ^; ^  U2 u) w9 A; N       gd->ram_size = get_ram_size(; F& h  m, d1 h% C4 S1 A/ T1 R
                     (void *)CONFIG_SYS_SDRAM_BASE,0 ~0 H9 |/ D2 j# X6 T
                     CONFIG_MAX_RAM_BANK_SIZE);% O% k& p# ^9 u5 F% m6 h3 P0 S+ R( {( T) a
      return 0;0 Y  y  p) Z+ Q6 l
}6 I* s4 ?) n" ^" m( R0 f- p

  ~4 e8 R1 c% r' \  R6 i" P. G  w% f7 e, L% O! Q1 C

; s& P0 Z* r5 b4 `  b
) N3 w( t# \3 r. A( `# {FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！! R& m6 y( S0 }9 e7 M' |
! y6 z* l9 s0 G# w' s

4 ]& p+ {$ N/ i* E% C

		自动登录	找回密码
密码			立即注册