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;
5 m2 G$ i! l, y       sync ();
; R! T" m3 G) M  o) p6 J+ d       *addr = 0;2 [( ~) g' [3 i
4 A' e- c8 K5 g+ U
      sync ();
8 R" \9 L; V3 q       if ((val = *addr) != 0) {' X+ L/ X: W' f8 R
            /* Restore the original data before leaving the function.6 Y0 I# l3 Z7 F5 |. u- T3 \
               */; j( {' q) Y0 @# L& l' x& }8 P3 C
            sync ();
) ^, f+ w# F( x7 s+ W) C' P             *addr = save;
3 d6 O; N. H3 s" T) w             for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {# C# f9 {- d1 \
                     addr  = base + cnt;+ Z( B; r9 \6 F. v' _. d
                     sync ();2 o5 ]$ T+ ?6 y- a0 \
                     *addr = save[--i];
) G" F" ~0 P! e, T! s8 ~* x             }6 G& ?4 q; }( F- B) ?
            return (0);# q, Y9 I! S& n& ^8 T
      }: k! O- O4 E4 q; C
( H/ B; o: T+ S2 ]4 a
      for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
- k5 {, s8 e+ x6 }# ?" k( i9 S0 c# _/ |             addr = base + cnt;       /* pointer arith! */- u, m5 |* ?$ b1 P
            val = *addr;
( b" g' F' C5 b5 c$ V( Q             *addr = save[--i];4 F/ u  K- c0 z8 i: x8 n( {
            if (val != ~cnt) {
9 q; k- k. s9 L* o0 y3 v# K" M                      size = cnt * sizeof (long);0 a: R) Y6 {* K( `4 k
                     /* Restore the original data before leaving the function.; f3 Y0 Y, @* \! }: K3 e' @
                     */) ]& A$ L# z: P5 t
                     for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {% a. O2 [3 v, W% y- w
                              addr  = base + cnt;( N* Q. p' V/ t& z( }( m% m
                              *addr = save[--i];6 e% N) `+ Q7 x, R
                     }
; N, A/ V4 r1 g, i! y                      return (size);0 v2 |8 g# l2 u; s! E
            }
8 {% |) m9 `2 Y  h% x       }# S! m, k: h# ~: {4 ]* R  d; O
* i; }# O" y; e  A; r
      return (maxsize);2 G7 V& j  \: u( l5 S4 I7 k
}' |! c, O4 f* U2 p$ d/ {
int dram_init(void)' P: ?; I/ R; N: a4 L
{
& P6 I3 D1 N/ U9 c       /* dram_init must store complete ramsize in gd->ram_size */
' A- |- c1 Z5 W, _+ j1 C       gd->ram_size = get_ram_size(0 F0 g2 a4 z7 C
                     (void *)CONFIG_SYS_SDRAM_BASE,
  p: D% X1 H' k0 u# S8 b9 z9 K2 T                      CONFIG_MAX_RAM_BANK_SIZE);
. S8 `' L! T3 S, ~6 r; l       return 0;
3 z: p4 _5 x$ g}
( ^# O  `1 h- F* n6 h6 b2 w7 M  p* s! g7 W, `2 n, v& \

! w$ W- Q4 Y! {6 X8 {8 t& `4 Z1 D$ {9 K$ W8 j
) p9 [/ v/ }- D2 R) F7 O* R3 u/ Q
FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！5 U0 G# w* X% O/ i

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