标题: TL138 uboot是怎么区分配置两款核心板的 [打印本页] 作者: Mr.Loser 时间: 2014-9-11 09:33 标题: TL138 uboot是怎么区分配置两款核心板的 核心板1：DDR2 128M Byte NAND FLASH 4G bit 5 m) F5 D$ ]% N7 K/ [8 n% ?核心板2：DDR2 256M Byte NAND FLASH 8G bit : f; h- h$ p# L }$ I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？ # W1 @5 x; B: ~2 k# f- w / u2 L' |# n( W0 b' I& I: K ?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？ 5 U$ m6 s; Y1 \) L, F2 m4 r, _/ D, I M: [1 r! S 作者: 2532609929 时间: 2014-9-11 18:55
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： ) `, S2 a: M9 \, Y& t- b/*4 L' E) v0 p$ v( D$ }, L" y
* Check memory range for valid RAM. A simple memory test determines 1 C+ x8 x6 F# S* the actually available RAM size between addresses `base' and' O9 ]7 G/ | j8 E; M7 m6 Y" O3 j
* `base + maxsize'. ; S3 k3 f! V) {+ _" M*/7 Y" }/ D: z C0 w
long get_ram_size(long *base, long maxsize)2 L' H- q1 j4 q+ K
{ ; g3 o. \2 E% @, n volatile long *addr;- q5 _, C' ~% E' c; s; o
long save[32];9 M4 H8 p3 N- c4 p% D% \
long cnt; - W( S' A# y7 i) k* N long val;0 {6 ?6 B0 a% e
long size; / r1 G' ~! k+ z' E1 o4 \ int i = 0; 3 q! L; [- q! n* f9 I 0 \& l% U9 s1 {5 P: [3 u2 X for (cnt = (maxsize / sizeof (long)) >> 1; cnt > 0; cnt >>= 1) {5 f2 {. Q5 B/ a& b; L) q( m8 }
addr = base + cnt; /* pointer arith! */! @! w$ X1 x# z& I4 S5 X
sync (); . V0 F: j/ ~- U! }2 @) F) c save[i++] = *addr;$ ~+ V4 M( G" T/ O: X
sync ();! W7 E. ]# L, y6 Q. v% ?
*addr = ~cnt; 6 z7 _& s3 v7 r1 i5 o) d. g } - j8 c6 p) l$ a4 m* o& l; q& A0 z. r
addr = base; 5 C' C- n+ A( ^ sync (); ' F3 |7 _ H- R4 I5 W$ r, c2 z save = *addr;. J) L" a1 Z( F) K" f/ W* O
sync ();, y0 ?7 C+ c2 K9 e
*addr = 0;8 h# Z9 r5 g% f/ ~
& w6 e2 e4 o, E9 E2 i- m# }+ }1 O sync ();0 \0 `$ m9 S: w
if ((val = *addr) != 0) {& v s4 T: N& \7 b% t6 u
/* Restore the original data before leaving the function. . F4 g- z- `$ l% v */6 m: `/ }1 o6 U5 m: l3 \5 T" v
sync (); l0 h- J( [4 `6 \/ U3 I# I *addr = save;' u: M# \0 l/ G) a
for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {1 H& L3 B# @4 X w4 `+ `8 D
addr = base + cnt; ( A, k! ]3 O2 ~ sync (); # z" v" @/ F- j! O/ J y" C *addr = save[--i]; 4 T5 l+ r( K, p' d9 N }# T* S& k0 q2 h, H
return (0);1 s0 N" F! ]) S1 P- v- c
}$ U1 X# B& V8 @0 }
( L+ P7 {" h8 ?' s for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {/ _0 i) `/ \" q, c
addr = base + cnt; /* pointer arith! */9 U% V4 M" N, m1 p9 a$ o9 U' ]
val = *addr; 0 L9 q M7 U. H, k( O9 C4 m; } *addr = save[--i]; . n* R1 ?4 g5 |) P# U. z" J if (val != ~cnt) {$ z6 H! w8 A5 u( R) w
size = cnt * sizeof (long); : K# I) t& K3 R$ G& v# c ] /* Restore the original data before leaving the function. 5 h# H! O, n* \$ B; |/ i9 T */ 4 r0 U5 E E4 |6 ]% Z for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) { 3 F: i6 X( g; f: M. r& | addr = base + cnt;/ b7 e# C" z4 K/ J5 ?. F- `
*addr = save[--i];( Q- h$ M$ ?$ P9 [' E7 r! r) h
} 8 h6 @' a* f9 @+ v% m& c return (size); ( ? s% b& N- [& Q( a: V }+ ^9 [9 P$ d$ v3 J! o% _$ i4 m7 N" k
} Y0 F& J* C8 O5 }0 B, Q: `
" i% Q. i) Z9 E8 x1 o% {4 B return (maxsize); ( h& ? V4 R6 q8 h$ d" j" F# d}2 c4 `0 V. d1 }8 ]& {% e) ^
int dram_init(void)8 E9 S6 ?: K) y
{) ]4 c& ?* r& g
/* dram_init must store complete ramsize in gd->ram_size */ 3 d0 {) _$ C' `! x6 w! Y gd->ram_size = get_ram_size( : R, C2 ]* ~" c) ~- k (void *)CONFIG_SYS_SDRAM_BASE, + M* Y6 V. j! e CONFIG_MAX_RAM_BANK_SIZE);% t6 @! C) B2 z f
return 0;# k0 F9 Z t* k" j
}* c, k- o a$ x- z. a0 y M
4 q7 M( F1 [- V: s) Z 7 S3 t$ Y' v O. Z h3 m - w, g1 ^7 I( c- j 6 X6 |+ _$ y" ?5 y" }- PFLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！# n, |) d7 g& S4 t5 K