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 ( ]% t7 |) s. k5 @1 y9 J核心板2：DDR2 256M Byte NAND FLASH 8G bit! g7 c4 X, b6 ]3 m
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？; o5 E+ F! }' L
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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？6 t* `; K3 U3 s. ]* A. J. ^
i6 ~- F: K+ M9 K/ M, q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： 7 g/ {1 }+ d* T0 d9 A ~/*( {5 k3 V! d+ j4 p+ y
* Check memory range for valid RAM. A simple memory test determines $ t2 h7 {8 d' w8 j4 x0 n! i* the actually available RAM size between addresses `base' and) s' s ^& Z6 ?2 g& K% V! I
* `base + maxsize'." z) z }: D; o. R4 \- _) o- z, Z
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long get_ram_size(long *base, long maxsize)! ^# T* w% w; }! D+ }, `
{ d; D8 S* }& }; s5 C% J volatile long *addr; 0 O7 N4 T7 A2 A: O( Q$ Z4 h long save[32];& t7 J* k% ^/ P4 {+ a2 ?
long cnt; 0 ?4 f: |% w% F long val; " F& H. t3 @* C0 z, b' b' d6 o+ a long size; & @8 d$ y* v+ n, M int i = 0;, y* z" e: m5 X9 W" u) ^/ P
0 s9 T8 y4 e* s for (cnt = (maxsize / sizeof (long)) >> 1; cnt > 0; cnt >>= 1) { & T$ W) b- |' t addr = base + cnt; /* pointer arith! */ 5 b0 n5 Y+ x( O' s" q sync (); _: [* u( `# S save[i++] = *addr;% N# `7 a! B* _% u& O2 @# l; x
sync ();, _1 c! W2 O- _) m/ L
*addr = ~cnt; ; t5 P: H% k% E; ]" m! ^5 @* }( ? } 8 f1 Z$ A4 i/ I& c8 P+ w5 ]' [5 _* Q6 ?$ L
addr = base; ( r- O: l7 P$ j+ T7 L sync (); ( N3 i# W7 D! j C$ Z. ^ save = *addr;0 j9 Q5 f4 B5 V$ f, V
sync (); f3 w+ i) l& }) ~. E
*addr = 0; 6 k' m2 ?' ? @) j9 o" @3 ` : L/ e- y9 S! c, Y% j3 D9 E sync (); 8 g& {1 I" |/ H3 j, k if ((val = *addr) != 0) { ! {, h# g$ R. W" ?0 M4 l /* Restore the original data before leaving the function.! O- V; c1 K% n3 I- ^
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sync (); 3 p% z8 T7 O* d' U. h$ A0 A *addr = save; ; }9 j, X& d3 R O4 \ for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) { 0 X6 D9 [5 X g addr = base + cnt; * l& |# [2 k6 v2 ^, S sync (); 7 X) v4 G1 w; e7 m *addr = save[--i]; ( m2 D8 Z& N* ], g5 U4 m2 r3 ^ } * M- e- |2 o/ h3 c U2 i$ S8 b return (0);, w4 O1 V4 a. i( M. H
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for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {" v1 d# m. \7 h) c
addr = base + cnt; /* pointer arith! */. W: X1 p) [" Z+ A: p1 b; ^
val = *addr; 4 Q- ~5 d; A7 I; M2 S *addr = save[--i];' h( V: S4 n* M2 ^* a7 u
if (val != ~cnt) { 4 p. I8 b' P3 Y+ k+ q) q size = cnt * sizeof (long); . n8 T& O# O. `& y% a8 @ /* Restore the original data before leaving the function. & ~9 H2 s; L9 x* }) O& I! E* w */ ; t- p: E* u# B) H; ]5 v( N9 R4 m& B for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {& R0 H$ P' f; k3 z: l6 G: `4 F# h
addr = base + cnt; 8 B5 I0 d6 N; i+ H$ y *addr = save[--i]; - a% h/ V1 V- m+ B } - g: `# O$ h+ Q) @# y) T/ V+ R return (size);6 w; i, a2 w- I$ \8 T8 o2 ?
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4 [ c# C9 F( W% O- `, {, }) m return (maxsize);4 v" s& Q4 Q& i! U
} . ^) N6 ^, f8 Dint dram_init(void) . U$ R ^# Y( t: \ I{* r2 P+ w" o, C7 s) m
/* dram_init must store complete ramsize in gd->ram_size */ 6 J f& a$ i1 _) s1 s4 n/ ` gd->ram_size = get_ram_size( + X1 i9 Y* A* D (void *)CONFIG_SYS_SDRAM_BASE, 4 o7 i0 u5 ?/ ~8 D( q CONFIG_MAX_RAM_BANK_SIZE);( ]( B3 {; G. A& ?. ~
return 0;& L7 z- |: k( U3 z
} ; H& N: u2 }8 V! h+ _1 }4 s, Q4 T2 J4 ^ ' [" ~+ b, N* C' o* r# u { & }! \ b! a9 X6 O8 Y$ R2 s, d$ ?9 \- L# M0 ^3 ^
- Y2 z5 Q# w- @9 d: }6 \7 dFLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！ : P5 C6 R W5 z8 N8 F ! k# u7 m( q; O2 {! |. j6 ^5 f 2 o. @' N- A) R" v6 a; }1 V% Q& m6 d) R# ~% O& c. z( M