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;
; Z4 q: i! y4 k. ~9 p3 ~  G       sync ();3 G% [: @3 u. L: K: {9 s( B
      *addr = 0;8 U1 a0 e# `$ g/ [6 j
- K) W& z( v! S0 \; m* E2 ~$ d6 o4 m
      sync ();9 n) z  ?; g0 O) R2 d
      if ((val = *addr) != 0) {
5 Q7 D4 D% l  Q, F% q8 ^/ |3 a& I             /* Restore the original data before leaving the function., i5 X: D6 s2 v2 Q
               */% p$ v' N" W1 I( M' [; f! ^& m
            sync ();
) f0 h& j' s- w( {             *addr = save;9 e$ k# C/ r% y& l+ }* r, k; R
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
8 U, H2 d  Y, J% ]1 b                      addr  = base + cnt;
  R8 d" F+ x# B# z. g9 Y                      sync ();, e9 A8 V( F! Q9 c
                     *addr = save[--i];' \; l+ ^4 J  Z, N2 z$ E, i# V
            }* }# w! {$ J# [  R5 G& A# a
            return (0);) ^2 B  N; g2 O" D& g7 s
      }
  s3 c% ?: P6 u0 F7 Q2 t6 e6 m  S  W6 b7 k; u+ U
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {5 C8 C5 Q6 z1 c; M. p2 K" X+ f4 B
            addr = base + cnt;       /* pointer arith! */
# ~  @- D8 ]$ ~3 D5 E7 a- b1 j' S             val = *addr;
  y. _1 `# E: J- h8 |0 Z             *addr = save[--i];
5 n* z2 z4 x3 h             if (val != ~cnt) {8 E4 q. Z4 [/ ^6 f( G# Q7 ~' A
                     size = cnt * sizeof (long);( o! ~: e0 x3 ]/ U
                     /* Restore the original data before leaving the function.
& U8 ^: f" m: j7 u( t8 D/ Z5 c9 ?                      */+ r, }- I5 y  e4 k- h! e2 G+ t
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {' c7 |; W" k; W' t. k, H# }  f
                              addr  = base + cnt;
! X9 ?& c  k. F- J  R) l# O                               *addr = save[--i];
$ s% k! h, K" p+ q. j- @                      }' T" t- V" q- y* d7 V3 Q3 e: |
                     return (size);
6 O. ]$ M' G3 e. M( C/ c/ `6 x             }: `2 K& E9 Z% G; y# }4 N6 d
      }0 S- u/ _) |+ d. _
: @( m* \/ T9 o* x5 N0 q( y
      return (maxsize);0 `( Y6 u0 t: W$ y. k
}, a5 D9 g2 O* E' N" R: p8 M; i$ o
int dram_init(void)( T6 S4 s( }+ r6 @( w
{
' N. O) s! a6 v2 d) ^" W9 I       /* dram_init must store complete ramsize in gd->ram_size */
# S6 P' _) @" J7 m7 Q       gd->ram_size = get_ram_size(
: v- i; _$ {) U0 N& e                      (void *)CONFIG_SYS_SDRAM_BASE,; ]) i% L7 K9 g1 a+ [& \
                     CONFIG_MAX_RAM_BANK_SIZE);
1 c  a2 h; t: V: d       return 0;6 |' L- x! ]' G  N2 ?
}* Y: v/ U! s8 ~1 b' V6 l0 E3 X5 r( f
. k! ~+ n' o5 W
4 J  q7 Z6 d/ p/ I3 X! d
( `; @1 `' x, U" d/ a
( K4 |+ e; j+ Z
FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！
: Z& B- `: d: _& p0 R% k( M* N6 O2 n

6 x, W3 `  s4 r4 p

		自动登录	找回密码
密码			立即注册