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
1 |! D! H8 r: G( m X
核心板2:DDR2 256M Byte NAND FLASH 8G bit
1 |( U# e& s% x* _% u
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?
: g8 E$ d9 N" w1 t9 y8 G
U! E0 N# y# k8 x, t1 j
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?
* Y( K" i; ~- L8 r. k6 W
8 B+ ]& U' s3 Z1 w
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:
" ?( S" n( e$ u n0 M9 A. {
/*
8 e7 t3 L6 U3 i7 N. b2 V
* Check memory range for valid RAM. A simple memory test determines
% t5 D5 `+ w1 e) b3 h' u
* the actually available RAM size between addresses `base' and
7 i) k: I6 _; G% ~! t
* `base + maxsize'.
5 A" L5 q7 B8 X) A! W( p
*/
: M$ {( q E; i: |3 Q6 F9 l
long get_ram_size(long *base, long maxsize)
1 y7 r7 w1 K* D3 O, i
{
I0 i$ I; d+ `! w' N
volatile long *addr;
7 Y- M. l: t3 g3 h
long save[32];
2 W- ?- @& Y! P
long cnt;
5 ^+ Y3 y' N( `; l/ l+ z
long val;
) @7 j9 x1 R. Y T1 i5 [' P
long size;
T8 Q ^$ w. h/ T1 @4 e" J) `
int i = 0;
& ^! c* E, N. K- y5 q
* Y' }( @7 N4 |
for (cnt = (maxsize / sizeof (long)) >> 1; cnt > 0; cnt >>= 1) {
7 t9 ]( c7 M! r O, P6 c3 ?9 m
addr = base + cnt; /* pointer arith! */
5 u; _9 l1 s/ ?
sync ();
% `+ Q7 s' H$ L9 \
save[i++] = *addr;
. `, i$ s2 {( a1 e2 L
sync ();
" l; o4 |* k( I! m& X
*addr = ~cnt;
" h7 L" m4 `1 l
}
' q$ U" D! _# l. ^6 g# S$ R5 A( c
+ t. l: W9 t3 a! A8 o" M h1 v
addr = base;
) U$ e: y, _: Y% q
sync ();
% `" r" Y3 }7 y8 B
save
= *addr;
}4 ?0 r/ q9 y& s7 E
sync ();
) v% b' v. S: A4 D
*addr = 0;
4 }1 w9 U1 E3 D
8 q, r% g4 [' ~
sync ();
- y* Z- W' {! b1 c3 a7 J* K
if ((val = *addr) != 0) {
, x* B, K! n: m) n! l
/* Restore the original data before leaving the function.
# Z: o8 {5 i8 _# N1 F% u% I. i+ ~
*/
8 A8 _5 c3 x2 L
sync ();
, D$ A+ I# B, N# x2 l( \% v# @' n
*addr = save
;
8 s% D# c8 _, `5 C9 ~$ T
for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
. c9 m4 j' Y% w% I7 ^+ I# ~' _
addr = base + cnt;
' H1 K9 T3 U! o' E$ R
sync ();
* T9 ?0 A* y, `3 F# L/ ?+ i
*addr = save[--i];
9 y5 ~ i6 F% K" q7 w
}
2 ~) U1 J2 a- Q* j6 l1 L
return (0);
! P7 c9 a+ F: w3 q, E r
}
1 ^3 N5 d; X, w6 x
! d9 y. I2 V1 o M0 b7 R
for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
! j1 w0 p7 S s
addr = base + cnt; /* pointer arith! */
4 q1 \9 G1 Z4 k; _# } r/ f( R A+ \
val = *addr;
) {4 B* p: r: L; [' j
*addr = save[--i];
0 p( ?$ o. Z9 W8 l" m
if (val != ~cnt) {
1 V2 u/ k# |) b& ?# C9 V& X
size = cnt * sizeof (long);
6 d: c# p3 U7 _3 V1 X
/* Restore the original data before leaving the function.
6 g' G: I s$ F
*/
8 W& ^. L+ g: b3 t. ^3 e1 I8 O
for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
' W- l3 y/ o; E3 V% C1 n
addr = base + cnt;
- p) j i J; x3 R
*addr = save[--i];
& a: _; S0 j; w
}
% I" F5 O5 ?9 q2 x2 |
return (size);
4 ?8 a1 B/ r0 T8 V% j; X* l: H
}
2 \. g1 G( ?: Q8 l0 ^- @) U
}
$ b& A, m; A3 v L0 b* e
+ s- G6 a& P' Z1 Z0 Y* f
return (maxsize);
8 }/ o8 c) X; @5 ]4 q
}
, y, w! v6 B* f# A- V
int dram_init(void)
& q' a% b7 K: m
{
! D) T8 e, ]4 I$ M0 h6 d
/* dram_init must store complete ramsize in gd->ram_size */
4 ?, h7 c# c2 J# |4 d. V/ A
gd->ram_size = get_ram_size(
2 J: I" q* O$ P. v
(void *)CONFIG_SYS_SDRAM_BASE,
0 J8 l3 X4 o/ @: a
CONFIG_MAX_RAM_BANK_SIZE);
. E: b& \1 W8 v8 d7 w- y. l
return 0;
9 O4 I- w$ x8 F; Q
}
$ Y. A, U& X4 F- ~6 h/ X4 {" t3 i
) p6 }1 s! d# c
) Q. t( y! o# u! A: r/ d
2 ~% X$ r) K9 V# _( r9 i
. h. U* d6 ]" H
FLASH是通过检查FLASH内部的ID识别容量,希望对您有帮助!
- E8 Z4 `/ H1 g3 R# ~ a
6 v9 V/ G5 H2 t9 ~4 A
- ]: a3 U- U1 k4 g8 G- T; i6 W+ `, v
; V. ]% G( v. q9 C" z
欢迎光临 嵌入式开发者社区 (https://www.51ele.net/)
Powered by Discuz! X3.4