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  |; b, d+ g7 S7 r       sync ();
* e/ |/ D9 m' O3 c  O       *addr = 0;
/ Q0 U1 a' t7 l# ?3 h
8 b9 ]% V5 V6 h) l4 f6 m" w1 {       sync ();1 S% p2 |  \" T# l1 B
      if ((val = *addr) != 0) {# b3 j. X# U. _6 j' S* n
            /* Restore the original data before leaving the function.
. v6 K' [( ]; D: {: f9 W                */! c/ P! U) ^; }  M) m3 P
            sync ();6 R- `2 R/ X5 x; _/ u
            *addr = save;
7 s% D: R. P; y( m& _' g             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
' Z4 h. i* q5 ~- R$ l/ A1 Y# }                      addr  = base + cnt;
& Q6 a1 v% j: _- G2 N                      sync ();/ J( _5 D- m$ D% a2 x' G
                     *addr = save[--i];, z! k1 Y# W: ?) c. w, G
            }5 T* u. m7 U$ v: D; D( h
            return (0);
4 ^. T) x* ^/ w( G! Q5 X& w       }! c% a- t9 a2 g$ e+ {  ^! }
5 h# G% d4 i. d
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
& ?6 ~! e  V8 z0 H             addr = base + cnt;       /* pointer arith! */
( Q4 [) b" W5 z/ Z: i/ T# r             val = *addr;0 x" C% k2 `# C* l2 @* I/ l# u. P
            *addr = save[--i];" m( P( y* ?6 U3 D" \( T  O
            if (val != ~cnt) {
, `- r' e) n6 u1 q                      size = cnt * sizeof (long);$ v; s" T4 z/ H% l! }( [
                     /* Restore the original data before leaving the function.
: s/ F; ^6 Q9 v& q. S" N0 V0 E                      */
' ?9 {' A2 W0 j2 J% M/ Y8 m                      for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {7 Q, m2 t5 e3 v3 W
                              addr  = base + cnt;9 H$ @- t4 ^# H/ |+ t$ n& h8 z1 b
                              *addr = save[--i];5 i6 X: G) w5 e
                     }
' x3 S8 P8 \% q1 @                      return (size);
0 [1 ^( T3 }: F6 b$ E. }; r             }
! M- e/ E: d. F8 C* f7 O6 i       }
7 E- o% f; k* Q2 O% P
  e/ x# v! q& O# U3 l5 F. s6 l       return (maxsize);
# R+ c+ U1 y5 [! N' Z8 ~& w6 ^}/ {. J- w# u0 S7 X0 _
int dram_init(void)
1 j( o5 f) e$ _& J{
8 J' {# @+ V) B/ u  N9 }       /* dram_init must store complete ramsize in gd->ram_size */
5 D6 B( L( {) l& \/ b3 \& }% r       gd->ram_size = get_ram_size($ A& a/ m5 p" Y
                     (void *)CONFIG_SYS_SDRAM_BASE,. [' S; i, O1 b2 I5 X
                     CONFIG_MAX_RAM_BANK_SIZE);* W, N- S- r- `/ h8 k7 J: o& N
      return 0;
9 m$ }  v# Y' `- X}  H$ Z& F; f* U2 O( a
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5 J! O7 P  B% @( w$ c
" D' i' V9 b/ E6 C% qFLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！, H1 ^0 A2 l. }& S# B9 P6 N

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