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 " i- b1 O5 V- Z' M核心板2：DDR2 256M Byte NAND FLASH 8G bit 6 Q) V; p$ P& \5 R) Z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？2 N/ n" E9 k% C# J7 B. j# y! c) n
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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？! R" E$ }. e' z) I, d- Q2 N
2 X4 A$ {7 u6 a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：! J u+ N/ r3 f6 C/ o5 W
/* * F2 h. I( I6 W# | d* Check memory range for valid RAM. A simple memory test determines1 o" A$ ~" R# ~' u
* the actually available RAM size between addresses `base' and ( E& w: e+ |+ ^- I. V, z* `base + maxsize'.5 {/ i( p L4 }' K% I" J0 Y! x
*/ ) I- L+ M! _5 W4 F& wlong get_ram_size(long *base, long maxsize) 1 [) r. @1 f% J+ h{4 S8 x$ H1 j; H- T
volatile long *addr; ) y; }# @: Q6 T+ ` long save[32];) @/ l7 ^" d0 ?( m% n
long cnt; 8 q K8 y3 a1 L long val; 6 x( p8 U2 [$ A long size; $ o3 J- M0 k7 `7 `/ a int i = 0; , e8 |+ u+ _/ b2 J' {" X3 N; Y( p$ M# y+ j' y9 l7 o
for (cnt = (maxsize / sizeof (long)) >> 1; cnt > 0; cnt >>= 1) { - c+ Z6 S. I! Y( ?8 G addr = base + cnt; /* pointer arith! */0 S" |7 z2 \$ b" [0 e& b1 p$ T
sync (); + X) m5 r }: ]3 V7 i5 K: ~ save[i++] = *addr; % h0 j) w; Z) \( T sync ();' k+ J9 Z4 ^' z5 [* Z3 Q
*addr = ~cnt; # S7 U9 u. b' G; d" w+ Z! n0 \) h } ! ]" T+ ^# g' N& p* L3 ?6 F6 l9 }' e" i: Y* U. C% r: D
addr = base;& r/ a4 o! B; N/ _2 a* u/ I
sync ();. M" j: j# c9 }- m
save = *addr;$ \% i' _* r a) O2 z8 u
sync ();# e. a0 c$ V# X1 U& R
*addr = 0; # Q; Q& I+ Z0 d* Q2 z( G0 A. U; b6 e; D( L- {' k6 z3 _
sync ();+ K- p% a5 P- p" f; ^" b
if ((val = *addr) != 0) {+ c/ m5 s$ ~8 V
/* Restore the original data before leaving the function.; P: W- c" r! b0 q* ?
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sync ();9 B% Z: y L5 v3 o
*addr = save;, E9 Y7 ?, g5 W y+ s6 G. J, A
for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {) A- C, W8 Z7 z% Q/ d/ C# U) l. I
addr = base + cnt; ) [! G c2 _) s3 M sync ();: b! Q2 M, Z- V* ~
*addr = save[--i]; * I% W; \* o& x8 q7 t! |2 f3 x+ V! R } 2 d' q( [9 N' t4 U return (0);5 g7 I( l) L) M2 G
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for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {! e: x4 ]5 i+ b4 ?9 {) F
addr = base + cnt; /* pointer arith! */$ s6 n$ k1 D3 K! V" s
val = *addr;! h; A( w+ [, B5 u5 L- x
*addr = save[--i]; . z; G! o$ t" W' ^ if (val != ~cnt) { 1 T a! \+ m, {) } size = cnt * sizeof (long); . u# |# b; v$ n: C- r /* Restore the original data before leaving the function., w( O$ ~8 j$ a# i/ l7 a
*/ 7 V) w- r& s0 \! T. V/ O/ F9 ^ for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {, f) H- H4 a( J
addr = base + cnt; # B1 k4 f+ M2 Y& K4 |& S/ a *addr = save[--i];" E5 I% x4 S S3 z
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return (size); . T L3 P! ^. S, w }- X% d: j. }6 U- C" \
}; P* F0 Z$ A( d' k' R
+ m2 _9 }% p8 I, D return (maxsize); 0 s+ u- Q6 v( V7 E% @}8 Y% R% s3 q6 C6 Z% ]
int dram_init(void)( F: }8 l( J' \: N3 o
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/* dram_init must store complete ramsize in gd->ram_size */; k8 d* r) E& U% s; B5 Y
gd->ram_size = get_ram_size( - D. E4 h: N! ]9 k% Z& D (void *)CONFIG_SYS_SDRAM_BASE,* ?9 T8 f) J) Q/ e8 Q9 r% p
CONFIG_MAX_RAM_BANK_SIZE); , V: g1 f, X6 f- r' z+ ~ d4 G8 Q return 0;+ d3 @8 D; y. b) y8 A8 D! c: H+ W% x
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9 L1 w6 W- }/ N9 Q, rFLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！ ( K- P( c) e, X" f" }6 L' Z! L9 b+ Y/ _; u
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