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;
. _, o3 s$ b; S- v1 ]: r' N       sync ();
; b2 u! G0 J% t  x% i% |       *addr = 0;8 h1 @2 e) W7 \) {
( P7 w! ]5 l8 v! q/ U/ \
      sync ();
6 ]5 g" Q5 V. [  \       if ((val = *addr) != 0) {8 m$ C. Y$ x1 v+ W+ t9 r  K) T
            /* Restore the original data before leaving the function.
" S0 |: w+ h6 S% p                */
! R1 D: ^5 `, U             sync ();
1 G9 [: q3 u0 z6 L4 _/ E7 \             *addr = save;
6 O* W  j4 @7 }2 m0 j2 M- V* b/ |             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
% a" x, i0 w' T$ [                      addr  = base + cnt;& l$ v' _1 k' }( w' y; o6 W7 j
                     sync ();
7 c/ S( p, T+ z' k/ v9 ~                      *addr = save[--i];5 Z% |7 \! O8 ~4 L% X# O4 e4 X8 Y5 R" O5 x+ a
            }) \- @, W" B5 E$ \7 d- l7 `
            return (0);
6 N6 ]2 U, M4 M0 ?       }8 m5 y0 z4 b( h: Q) q7 B
# ^4 z3 D& F5 S; a6 M3 Y
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
6 ^1 t3 P, N: m1 w- }0 ?             addr = base + cnt;       /* pointer arith! */
; r9 I* W) P. ]' q3 O% O) F             val = *addr;- Z7 N5 ^/ k  r1 }% Z+ c! }6 P# I
            *addr = save[--i];' K; v7 C, q  r) o$ m- F
            if (val != ~cnt) {
+ i, K" c' @& T- \% O& a) {                      size = cnt * sizeof (long);/ m0 O% Y: p2 d# h/ o& m! T
                     /* Restore the original data before leaving the function.) {9 _: a/ ?1 y
                     */' C8 g% c3 E) ~- q9 p6 j
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
! M$ s+ g) j8 S* d  v# G                               addr  = base + cnt;  B# e* Z+ T, [5 ~5 u4 G" j( G4 r
                              *addr = save[--i];; J# `) x& s8 x
                     }3 _9 R6 t. H6 g1 v0 U/ ~
                     return (size);
1 a: K# V8 X" B9 i% u8 c( I: L. ]' t             }2 G* T3 a: o) p) B
      }
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      return (maxsize);
7 D# L/ ~$ m* u7 T# [}2 Q& f2 l0 A! d$ D6 C
int dram_init(void)
7 \: r; W. Y, g6 I& b) @{
! y1 X' x! e3 B$ Q8 q# Y       /* dram_init must store complete ramsize in gd->ram_size */% `& I7 M9 Q) s0 a$ {( i
      gd->ram_size = get_ram_size(
0 E  ]) v) u6 O5 p                      (void *)CONFIG_SYS_SDRAM_BASE,
7 w, i) h% J/ v7 j! ?- X                      CONFIG_MAX_RAM_BANK_SIZE);
) y: z5 A4 w* ~  J" @) K  Q       return 0;. |9 Y9 _3 [! U/ M4 I9 p, B
}. y+ I! l% w; g) {( F, y, f

2 U, Q& L0 x6 G: E, f7 _9 @5 i# p! Q/ S1 Z8 p- G

; F( z5 X/ r# x3 `. B, E" ]' [. _: W8 c4 W2 L, p
FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！3 n  e: u1 G) s/ q- q

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