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;" o, k3 `7 q7 i9 b& ~5 d& L: y
      sync ();4 d% W& S& p7 I, [0 M& f
      *addr = 0;: K, C+ g2 u8 z+ P, c

8 [; Q& V  ~9 ]1 C       sync ();
' x: b; j; z5 d* P' ?& u3 a; L       if ((val = *addr) != 0) {$ s8 G+ a1 }; S' ~- X
            /* Restore the original data before leaving the function.% A' f# U/ e- @$ C# d
               */
' W3 H% ]" x. j2 W) |             sync ();2 F8 D! P: p" A6 ~* H* y9 W$ c
            *addr = save;( y$ x8 `8 F) N1 b/ a( m- {; |
            for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {' j7 o8 p: ^- ^
                     addr  = base + cnt;
( j( K/ `( j7 O: s$ ~6 H$ [" r# T                      sync ();+ b6 B+ f! m" y9 Q: t' Y2 t3 h1 a& c) l
                     *addr = save[--i];7 x7 P, |2 ?  B: h  `
            }
( X  b6 @$ b* A0 v             return (0);
) F2 E; S/ h! f( n3 J) s       }
" k& r2 ~- A" u1 G
* s5 y1 J7 B. _8 U( j, [       for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {3 n  B/ Y. P& t9 G
            addr = base + cnt;       /* pointer arith! */" u' ^/ j& {% ^# n9 q
            val = *addr;
# K0 e6 b8 x0 P' l  a' T3 A             *addr = save[--i];
' [4 d) p1 J  B4 q             if (val != ~cnt) {! e1 y: K; |' C+ b! E- W/ V
                     size = cnt * sizeof (long);3 c' x3 f/ m! b9 _
                     /* Restore the original data before leaving the function.% c' X/ R  z  Z3 X5 k4 \9 T* n
                     */
4 d( U$ U- o; U2 S" e                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {& X- w0 U" y& t% h. S6 X' |* k
                              addr  = base + cnt;1 f( F) \5 I' C, C
                              *addr = save[--i];
. s+ M! T# {; I/ Q1 D  M5 }                      }" k: H) d0 X% @( S& }: d1 a. q
                     return (size);6 O& S/ W9 {8 _' `) X8 _
            }5 R7 V0 \3 |9 ^9 L- L
      }# @* D9 A1 n. F
  ]6 x" O7 G3 R2 F
      return (maxsize);3 c  r6 f0 [7 y
}
4 B# o( R3 \9 q: Nint dram_init(void)
7 E) B% j+ \# k  T{
6 e  Q4 u" B4 d' _5 _       /* dram_init must store complete ramsize in gd->ram_size */2 l8 y1 Y+ S0 F3 k! K( [
      gd->ram_size = get_ram_size(
& S5 N$ g0 r5 z6 S, \2 m                      (void *)CONFIG_SYS_SDRAM_BASE,
( ~$ y/ \8 o1 q/ C# V3 {& h: b                      CONFIG_MAX_RAM_BANK_SIZE);
+ Z( w# T9 v9 N- S3 ~# ]       return 0;
$ P+ N* P6 g% H5 U( N- r}
8 z  j  e. s- h+ {8 F
% {/ ~6 w% X+ @1 A6 T  l

. p3 }- ^/ Q8 j7 ~4 h, @
; d* R. X) ]6 P& v5 D2 I! g* AFLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！) X9 G+ v5 E3 Z5 ~4 |; T3 y; \( s

# a5 m5 y8 @. V) I% ~. z( E) h! X- r- u4 |' Q4 w. s

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