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;+ x7 W( B1 e* U
      sync ();
: @2 @4 U" ?2 N5 i2 f/ W       *addr = 0;, q+ p0 a% m" \2 ~  Y/ u* t8 Q, G

! N" p  h5 ^; R) i& O       sync ();2 ^7 r. G' V5 e) T4 o2 R
      if ((val = *addr) != 0) {
- B9 c" ]9 f6 c. E             /* Restore the original data before leaving the function." D* ]" O, f" a( E8 v4 o- ^
               */' a2 |# u$ {' D% J" H
            sync ();$ `7 q! Q$ s( t
            *addr = save;
% g( B( r) u: f0 ~+ |             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {( g+ |  U4 O; I: |
                     addr  = base + cnt;7 d* Z; j* {3 c  }0 j, S  H
                     sync ();
. E1 ?' Q. \2 _# j! @+ l0 p                      *addr = save[--i];3 g$ y0 U# K8 L0 Q  m4 }
            }
+ P, k7 ]  f9 N7 N' b' G# n6 `) B" k             return (0);3 V" o- ]! d$ I$ B" C6 K+ m/ x
      }
2 @0 j, _2 w- F7 Y1 D, F( G3 c" X) e  ?- ?5 B4 s) W. ~
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
7 d' R( s8 A) j% o8 e8 g3 N' |- o             addr = base + cnt;       /* pointer arith! */6 X" a# @, \, F- }. z2 b7 Z9 \
            val = *addr;
1 s( ^6 Z! @$ J! u& |             *addr = save[--i];
9 _" P$ ]" {( \1 J" K& p) V             if (val != ~cnt) {
0 l7 c# L6 d% Z1 `                      size = cnt * sizeof (long);' O! O  d* \% E' n( g% G
                     /* Restore the original data before leaving the function.
  w$ I! i* I' Q% D$ ~                      */
* @8 e/ V, V  s                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {& |# }% ~8 Y5 S' P/ o7 z
                              addr  = base + cnt;& j* S2 X$ j" i1 m& x1 l
                              *addr = save[--i];
, r& j6 m0 {7 [9 H3 I7 E2 Q                      }3 u: t# q) I, x: M5 {( l
                     return (size);- s2 @6 C- D4 ~3 J
            }
+ w% r' L2 q4 Q       }9 j9 P% V% {7 T
  g6 x* r  B7 ]8 O5 `8 Z
      return (maxsize);
2 F4 ^' U0 Y) h* M}7 X- L/ W: \  g3 ^% K5 H' Q- D$ |
int dram_init(void)' S8 a% u7 a' p0 r) }# p
{
! D6 W- @5 S7 l2 `4 Q       /* dram_init must store complete ramsize in gd->ram_size */! Z, |  h0 Y# h3 x' @( B, C; x5 m
      gd->ram_size = get_ram_size(
' B. ^, h, K9 H                      (void *)CONFIG_SYS_SDRAM_BASE,( N8 V. M# C+ f+ |
                     CONFIG_MAX_RAM_BANK_SIZE);3 |- L: G& e8 U+ d) V
      return 0;
# v( h% m! W8 K/ r+ k3 t& h+ h}4 t( y1 z" v9 T. o! h
/ s% }& Y& E: [  g2 O+ d: I8 V8 z. {
% g- f4 e. z! X* n

; n+ s$ q: E/ M, }5 z$ c5 D2 B" c# Q# R1 }: o# g8 X
FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！6 z. r$ K, [1 s" `3 ^$ P' h, ?
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