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;
. L8 \8 E# `6 I" S6 E5 v, p4 u       sync ();
$ N9 K) H8 a( T3 U0 T" \# Q, M       *addr = 0;, ?6 l' ?. @5 G8 U% s# O
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      sync ();$ I5 F, \! O( Y( f$ c
      if ((val = *addr) != 0) {* Q2 m  p' v' V
            /* Restore the original data before leaving the function.
6 i! e" E: E; A3 y. o                */
" b3 ?/ l9 c; L" H             sync ();
% `/ H( d* m% z% e8 \8 E             *addr = save;
" c9 j: G8 B) F0 J             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {! k2 K1 ?. w3 |! }5 D' X( n/ ~
                     addr  = base + cnt;
9 Y5 {+ }) i/ Y" y                      sync ();
! a0 Y; C$ x0 F. D6 H2 e: D                      *addr = save[--i];& [" r% _+ M  _2 i7 h2 z+ g7 B
            }  h2 C. D5 A9 E) t7 C# s
            return (0);
( R' Z; L/ b( Y7 Z% h- k       }9 A9 ~( u" h! S% z

, f+ N- j4 [  @       for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
- f$ Z; U: p: E1 C( v& j             addr = base + cnt;       /* pointer arith! */
0 f7 w$ e: d. X6 Y0 o) P5 l4 I             val = *addr;, _: d- G+ |1 m$ j# @5 E8 j
            *addr = save[--i];, C8 a7 k5 v. A0 M
            if (val != ~cnt) {
* B+ \' R0 h- k                      size = cnt * sizeof (long);
9 W* x* e2 k5 i1 Q                      /* Restore the original data before leaving the function.
& P3 g( Q1 H, c  i: M                      */
' L5 o* _& W  ^* k5 Q- U                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {% ?7 [$ d) c# }) Q) F% w5 {, u  a# O- |0 ]
                              addr  = base + cnt;- D5 R: o. s$ K: l
                              *addr = save[--i];; L0 R- @" Q: `4 X6 H
                     }1 W- G: x4 b& F  o6 R# Q0 N
                     return (size);
+ m2 `5 a7 Z, l7 u* p& G7 \             }
3 g6 l8 B2 q' A' L& G- K) Y  p       }
+ J# g( J- b2 @3 b
; \3 m/ h# ?) v2 M       return (maxsize);
: A0 ~' ^; X. A6 n: o) Y}
$ b" w  }6 h$ V# q# R. Nint dram_init(void)
; K6 ~7 B5 P/ [: ~0 i8 @  g{" r& Y4 E0 z  r) N9 D- J, T: Q- y$ h
      /* dram_init must store complete ramsize in gd->ram_size */) R+ X& H8 m+ k( i8 }% w
      gd->ram_size = get_ram_size(
0 d' D! K/ o* y* g$ A2 p$ m6 f                      (void *)CONFIG_SYS_SDRAM_BASE,
2 h" d3 Z6 ~! n, O5 l% Q                      CONFIG_MAX_RAM_BANK_SIZE);) C2 Z! ^0 l* e
      return 0;, l* D$ Z7 ]- l# u# p  \8 f0 f# k
}
# Y5 g9 {% I. `4 U4 A( T2 X! Y: p) @" i% b1 d" k  v

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2 H+ q0 ^$ x! A
$ b5 a. g* @7 ?+ D! x, U2 Q3 a, r: ]FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！. R6 z/ T5 l  b: a# T' c) ]0 {3 d

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