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
8 h2 y& ?" Z' y9 s2 i q5 }
核心板2:DDR2 256M Byte NAND FLASH 8G bit
. ~6 }* G3 Y5 \5 Q% G
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?
! I1 Q( \6 K# U5 {6 f
1 `7 C! @" o6 D+ y
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?
- l# T& X) c, M/ f
. e9 v8 T; k7 I4 {
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:
/ _/ C. F, r9 t$ m1 _3 T% q* _5 m
/*
* @. V) `6 f$ h7 O
* Check memory range for valid RAM. A simple memory test determines
+ ?" |$ g; y2 D) K1 n* x$ D: M
* the actually available RAM size between addresses `base' and
V4 Y. A0 J& Q7 T" K" G
* `base + maxsize'.
& n/ S6 D. ]' a7 q; M
*/
% ?8 b2 [/ T5 y+ `' Z
long get_ram_size(long *base, long maxsize)
% ~/ x9 a' O) y& `! m( W- t
{
1 o4 `2 m- p& |% R+ f
volatile long *addr;
7 s% L/ T! `" b b% e
long save[32];
3 r& G' v, g* D# N3 Q% s3 q
long cnt;
% ?6 Z" ? T+ L. X/ h% x, J& ^
long val;
% ?& I: T) V: v0 W$ W5 u: C
long size;
' s% I# d v5 {% C) U2 a
int i = 0;
" N5 X; r7 x3 A6 ]. v7 A
f4 l, t( i9 v L; s5 a
for (cnt = (maxsize / sizeof (long)) >> 1; cnt > 0; cnt >>= 1) {
$ L+ A- O- w, Q- U
addr = base + cnt; /* pointer arith! */
' q! h% P+ }# v; x
sync ();
, M" b- ^. @# h
save[i++] = *addr;
# z& e) F: C1 x- H# O6 ?; R% L# `
sync ();
. ^" h2 K4 M6 I9 ~4 e2 O$ X' l; E
*addr = ~cnt;
. i y8 ]7 G% j2 G' s; s% H
}
: O) F7 m4 C5 x# d" x+ ?3 A, }
?; w) A8 }$ @4 F2 \
addr = base;
* ~% U9 ~. M7 J
sync ();
% ]- Z9 j" a5 f
save
= *addr;
5 j% B2 u6 K, k
sync ();
: C" K& ~; T1 q& o' C3 H* x. p4 N
*addr = 0;
8 ?- q( x# j* U) @/ P% X
6 G+ B' `$ B+ z6 x! F
sync ();
3 z9 S( l0 A. @9 ^2 f! |
if ((val = *addr) != 0) {
& i3 V! S5 F- B6 B+ @
/* Restore the original data before leaving the function.
4 J% S) y& x, v" I
*/
- n4 L0 Q9 A: L
sync ();
# W5 ~* c9 g" M( n3 M
*addr = save
;
5 l! F; `7 \: s# X! |
for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
7 a7 u1 [, F) z: \5 |9 Y
addr = base + cnt;
. @: q9 c4 ?) D4 ]. r
sync ();
0 t, Q0 N9 z1 V# \. p" n# Z7 `
*addr = save[--i];
: m7 @1 J- \5 K1 Q( n
}
% g7 y0 `7 Q6 C' g
return (0);
$ O1 f" J" ?: }1 ~; i3 r. ^: I
}
( \9 @- y4 b9 V# a: S) d* m) A6 d
; p8 o) q: y {0 F% Q& ?+ g7 O- B$ @! w
for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
- }5 M, A3 x, J+ m, q
addr = base + cnt; /* pointer arith! */
9 D/ K2 r" x8 e
val = *addr;
6 k4 |6 R N* x+ e% M4 ^3 @; Q1 f' _
*addr = save[--i];
! Z7 ]) n- y6 \8 P& {
if (val != ~cnt) {
# q9 q6 V! g. ?* e6 Y
size = cnt * sizeof (long);
) \( u" V3 O0 F
/* Restore the original data before leaving the function.
: W! Z, K, N# ?& ^5 n+ C
*/
0 j. V7 e" p8 a! M& D0 N
for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
/ o* S( f J8 d& C0 V5 u
addr = base + cnt;
( A" r# c& U' Z6 L# L3 L
*addr = save[--i];
% t6 F9 e4 ]8 G# \0 t/ q! \4 \
}
# w9 I$ I5 [/ Y
return (size);
, x9 F+ Z M# y8 u, i* J$ Q
}
$ f. X' `( R) G6 Z1 Z
}
( y0 A& s4 \( K: {8 a, A M
Y8 O2 t: j8 K; G( d
return (maxsize);
2 B* c8 X! a9 t/ ^- I5 h1 S9 b9 G. I
}
6 M0 k C h7 E/ Q2 u! D8 m
int dram_init(void)
% }/ j9 I* y: g$ x' }
{
! Y% |4 g7 q2 q$ G: Q
/* dram_init must store complete ramsize in gd->ram_size */
+ r- J6 V6 n1 e2 I
gd->ram_size = get_ram_size(
a. D) ]+ K O1 y6 ~ F/ U8 h" [
(void *)CONFIG_SYS_SDRAM_BASE,
- v8 _ g- |5 X8 Q/ L
CONFIG_MAX_RAM_BANK_SIZE);
5 r2 y9 o$ T9 C7 u) A
return 0;
2 Q* c2 R% C1 J" ]& @, K2 F
}
1 Y7 F% f+ M2 r, f
- f9 a E9 M: U( |/ S, |
, K4 F7 w- m! W& F3 A _* ^. A0 t
" S' S, h7 G) J+ y/ _. t9 R
3 B/ L; W' M/ M. c9 W& ` T& k0 z
FLASH是通过检查FLASH内部的ID识别容量,希望对您有帮助!
2 Q* G6 S2 N' U7 e; F
; x+ m0 d, l; p; }: ]
' R! j4 R1 T+ X8 j7 b! M
: b- ?# q" r) p7 _9 a- z7 X6 E
欢迎光临 嵌入式开发者社区 (https://www.51ele.net/)
Powered by Discuz! X3.4