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
+ |& z0 ]$ N2 \3 |9 h; n/ b5 R
核心板2：DDR2 256M Byte NAND FLASH 8G bit
* p: Q0 m& X8 C) p
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？
& F+ J" H, e9 Z- q" T' R8 F
* ]2 O& S& R/ w' x8 P8 W/ T
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) P1 l% `# b- s8 g
+ T7 a9 B+ ?5 L2 n* { 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：
, w& z, t5 D' j4 x5 Z1 W
/*
3 W. ]2 d, f$ m- K
* Check memory range for valid RAM. A simple memory test determines
* ^ {2 I! x6 t1 f6 D8 [3 F* Z
* the actually available RAM size between addresses `base' and
& n- M& J/ y& q( A
* `base + maxsize'.
4 q; G$ u, O( O* u
*/
$ X/ p8 z& J: ^; m' V0 P
long get_ram_size(long *base, long maxsize)
/ ]! D8 T4 n) T
{
4 I( ~/ I" j) k0 t; w1 a' e- S
volatile long *addr;
" C) E* b, ], G: |
long save[32];
/ J1 P' A' {/ x
long cnt;
2 d! O; {9 c8 d/ Y7 \6 S" n) D
long val;
% U' g4 t8 Q \2 H
long size;
3 X- ~% N7 y. U% q7 A. {
int i = 0;
5 d# ?* r; d7 x' _/ l
! W7 q' L1 v% Y. D
for (cnt = (maxsize / sizeof (long)) >> 1; cnt > 0; cnt >>= 1) {
5 f4 ]# o1 ~5 b, U9 X
addr = base + cnt; /* pointer arith! */
& r; q4 A' g' n5 G6 h
sync ();
) u7 S. n% P- u0 k
save[i++] = *addr;
$ C/ d; x! W9 U
sync ();
' D I9 R V$ j1 { V
*addr = ~cnt;
: ]5 Z9 p5 D7 N, }% c3 f
}
+ ?7 t* j6 B0 d, y% k: _
. a1 s. E6 l7 {: p5 p3 R
addr = base;
% `' J3 W: A) G4 _- F/ @
sync ();
) Y+ H; N- h3 u# @
save
= *addr;
& c& b8 u7 @& n. m+ d! e/ p$ Q+ M
sync ();
7 p- w% [0 p+ F$ V
*addr = 0;
; t6 l' H+ w( i: G" e: T& U$ |
6 C' g' k6 D6 m- u2 c* h
sync ();
$ n3 q! B/ D- ?0 l" B
if ((val = *addr) != 0) {
, @( X) P: |% J* ]9 Q
/* Restore the original data before leaving the function.
' s5 A% p$ R; r, k
*/
. S# z: Z$ F1 h6 D
sync ();
) d9 b2 A6 _3 }; [$ L' X3 G
*addr = save
;
+ P# {! [! s' Q+ i& c
for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
! S! F3 l1 ?7 N2 W" G5 z- _
addr = base + cnt;
5 Z a a2 d6 c4 c! X, C, a4 n
sync ();
4 ^2 _: {: F, j0 J. y
*addr = save[--i];
! b- E5 O g" P! k! Y6 b( I
}
8 D( j; y/ E/ d% C4 G
return (0);
5 F4 Q; [: R+ o0 j9 p8 K
}
3 l3 U1 s9 G( ?2 l
' m3 \- W. x- x& N$ I
for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
! y: W+ P$ N9 r6 k, L! `; Y$ W
addr = base + cnt; /* pointer arith! */
% T' I. N' [7 t8 ^/ N/ m
val = *addr;
d* \) J6 b) o
*addr = save[--i];
0 l; y% [0 ^6 o3 q2 Z! j
if (val != ~cnt) {
9 O' w) w8 _% M" T. t$ ?; m$ `
size = cnt * sizeof (long);
* |4 G. U4 v! r# X$ b$ ]3 U
/* Restore the original data before leaving the function.
6 @# L& h; R% e8 M W8 b( Y5 @
*/
+ S0 _6 W! L/ f# x" b
for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
) }8 \5 ?" H3 b! G9 n( w: a- Q. B
addr = base + cnt;
$ g$ k. E% Z% P+ d+ O/ S
*addr = save[--i];
( K c+ Y' s" z5 S+ f! D
}
2 U; |$ u+ e. }* q+ U _
return (size);
& N( C# k( j' _
}
/ h5 i* I0 q! h, I! X% g
}
! Z3 D. H+ [0 ~, D
2 H- a$ `/ b9 K1 C0 F: l
return (maxsize);
8 Z4 W* q3 e) s
}
( F, Z1 V [0 n5 e+ a7 Z: \
int dram_init(void)
5 F" K% Q/ _7 x3 S) w0 J! ~: s$ x
{
: f& b; f, Y+ N5 k
/* dram_init must store complete ramsize in gd->ram_size */
" r- c0 ]5 S# n7 u$ h* i
gd->ram_size = get_ram_size(
& Y {: K3 S5 g! @& E* x
(void *)CONFIG_SYS_SDRAM_BASE,
4 d. n% o" b7 V( @/ i% s
CONFIG_MAX_RAM_BANK_SIZE);
7 s& }+ Q$ y: }- k7 z/ u- N
return 0;
3 e- m! Y& `" S5 G2 z
}
6 @8 x% w( c7 j
- q) `( m4 n3 v
2 E$ I7 p/ t# z8 w5 e
/ A- w8 t. G0 O5 ]# O" O k( |
" n' j+ ?2 f ] I, |" W& W
FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！
4 ^8 L7 e7 b t" ~' B
' D6 ?6 @4 r ?
g4 N% H+ C* S
7 {/ n' C4 w7 f. d) |
欢迎光临 嵌入式开发者社区 (https://www.51ele.net/)
Powered by Discuz! X3.4