嵌入式开发者社区
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
7 n% N* a; d" J3 ?) w. [
核心板2：DDR2 256M Byte NAND FLASH 8G bit
1 I* T& D' y" {. E
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？
3 Z- N; e4 z- {* a
: s) r! D; g8 {
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？
0 r0 p l2 E+ f7 U
& L- c8 _* v0 M2 ?0 }
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：
6 G2 U7 k @ Y: P
/*
! M2 u; A1 u3 L7 e
* Check memory range for valid RAM. A simple memory test determines
( ^" ^! t2 x8 K% J% w8 O
* the actually available RAM size between addresses `base' and
" H/ V9 C9 U0 A- C4 n+ ^- V
* `base + maxsize'.
0 i* \' `7 ?% d% O+ i+ v" w6 C7 c3 P
*/
/ I2 D( g! i9 g4 i( W$ Z
long get_ram_size(long *base, long maxsize)
( A9 b; V8 N; B8 C
{
: R; L8 E, m9 W: r& v, o
volatile long *addr;
, w- y( }2 Q# c. ^
long save[32];
3 m; B* [$ D& i# w/ u# d
long cnt;
8 O* k0 _% |2 @/ T; T' O' M
long val;
! b* W# |/ s/ C @, S0 _) f
long size;
, f8 L0 W. A. e0 H: t b& P$ g1 `8 \, \
int i = 0;
( _% F/ e" u, ]+ B
( L- H$ x" W- I+ V$ m" W
for (cnt = (maxsize / sizeof (long)) >> 1; cnt > 0; cnt >>= 1) {
- g" r, l( [% p8 h6 G8 m
addr = base + cnt; /* pointer arith! */
) |9 U2 P% f4 {% X
sync ();
5 o9 e3 I- l: h! ~* {
save[i++] = *addr;
2 O4 h# ?* y7 r7 [" C: Z" f) H
sync ();
2 S* q" Z, I- }2 C
*addr = ~cnt;
# z- |7 E1 w( {' c
}
( ~& P+ g- v; P4 l2 P0 M' w! ?
% [. |7 J) }1 w4 u- j' l
addr = base;
- B5 ~8 e6 w, M$ C
sync ();
& k# s) v3 M) @2 j! P" }
save
= *addr;
4 H6 N }0 d0 A x
sync ();
9 C" r6 I+ T- J( `. E' m8 A8 A
*addr = 0;
# c( Z+ K3 O* c0 p5 D
) b; k0 p& Y* h8 h7 m% ~3 \- G# [: h
sync ();
- L( Y7 {$ d$ P0 {7 W
if ((val = *addr) != 0) {
3 j: M- D) Z5 u4 x* j% p
/* Restore the original data before leaving the function.
7 R# A4 _" [+ i+ e/ F5 O% D
*/
$ x" Y% H6 h) M u* U# l5 ?; V
sync ();
8 e1 P- L( J2 F, l: y, a
*addr = save
;
: ^/ ^ [- p1 P/ {
for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
$ Y5 C0 U g6 Y8 e1 s
addr = base + cnt;
; G' A4 T. h0 J5 M& S- D3 t
sync ();
/ S: q- j2 w4 o* u! r9 ]3 ~/ K7 L' P
*addr = save[--i];
! h1 n3 Z& y% T% Q7 `
}
. m' n/ ?4 [0 S+ g" E3 a8 T) @. J
return (0);
D( q1 C" }: @& z) g! d5 |9 \
}
' ?" v& t- C2 E# m+ T
( z) d* N, G5 l9 {
for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
! _5 o+ z! O& o" @7 K l
addr = base + cnt; /* pointer arith! */
6 W& T( |- X/ t% W. g0 ^
val = *addr;
0 k: F# Y o: S+ q
*addr = save[--i];
8 C" _5 k! l. |& _$ x+ u2 b
if (val != ~cnt) {
9 `, f) v0 z1 L5 m& J8 ]
size = cnt * sizeof (long);
* T% z# y7 t! O7 Y' p8 g
/* Restore the original data before leaving the function.
% S4 d d8 d8 Q! V# i2 Z: J
*/
8 \+ p2 T% H! t \" |. ~
for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
+ T) e1 W/ f0 o1 k& D
addr = base + cnt;
& N f. a9 f) b2 Z9 \
*addr = save[--i];
: Y. j* }7 x+ t: ?
}
# |+ f* S' @8 r: V
return (size);
; V: Q2 y' k h ]- X/ N
}
# o3 {* r* d( D Y# f: ^
}
1 s/ B- G- W; f- R8 `
/ ]$ s" d5 z* O3 g* T0 C2 n
return (maxsize);
. p- n: R9 q# A1 y* x( o
}
; W7 |: D6 U* n$ B6 Q
int dram_init(void)
$ h* m& y; q; T7 l( p
{
, g( j7 V& D+ t3 {5 H
/* dram_init must store complete ramsize in gd->ram_size */
/ `( L2 A% u* Q5 R# Y+ N% {5 q
gd->ram_size = get_ram_size(
7 E4 P N* z8 G" O- W0 ~+ u
(void *)CONFIG_SYS_SDRAM_BASE,
1 ?# Q2 T, w1 I6 K t5 E
CONFIG_MAX_RAM_BANK_SIZE);
G% c: E% N% S5 U: c( t' |2 O
return 0;
( S1 r8 i, n Y8 b3 j1 ~+ m
}
0 L* \/ f3 `' I9 X1 g C" [
$ Y$ a! C: M* z1 [
9 a0 P( D4 z- B" `! v
: f/ b' f4 m8 [5 C0 _* F
3 I& J/ A6 `1 m6 }! o/ Q; u
FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！
/ h& l' M- Y" y6 h. Z) ]
& Y, u7 p m7 C) V
3 |; p9 B0 p) N- \. E- [
5 O! ~9 g; z4 a! k% |9 o4 H: l1 g
欢迎光临 嵌入式开发者社区 (https://www.51ele.net/)
Powered by Discuz! X3.4