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
+ p8 h+ e( G9 V. F3 {) Z7 J
核心板2：DDR2 256M Byte NAND FLASH 8G bit
( `9 E& @) }# i* {3 o' d1 V
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？
1 {7 ?: m) s6 ^$ S4 e- h( @
( D" G+ o5 a& e- X
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？
( {& V! @) v! \5 p, |4 S5 w
" B8 [" U5 {: d3 D
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：
& X0 D1 ^. W# f, H! w, B. g
/*
! ~; `; P6 ?" Z' u3 {
* Check memory range for valid RAM. A simple memory test determines
0 _# h7 U( O+ O/ n: m
* the actually available RAM size between addresses `base' and
! k; `2 J9 ^6 r( D& z1 @" S
* `base + maxsize'.
# Z, t* z" _) p6 g# ^4 ~" r1 q
*/
]" a1 r% O9 q( @# w# R- Q
long get_ram_size(long *base, long maxsize)
A( d& `+ [# S) h) ^3 h8 a
{
8 d. U( s1 D2 ?4 `
volatile long *addr;
6 e' P3 m( j9 ?8 t2 O% _- [
long save[32];
& z3 }! P9 g& X9 G/ v
long cnt;
9 j1 X4 J' x# _
long val;
. ?8 N" |7 X; o+ O
long size;
5 q* S5 o' |4 E+ ?1 U
int i = 0;
* Z9 `# ^3 s% W$ w
* U% T- E) n+ c( b w; E
for (cnt = (maxsize / sizeof (long)) >> 1; cnt > 0; cnt >>= 1) {
* s5 p( n7 Y. T4 w+ W6 m1 ]
addr = base + cnt; /* pointer arith! */
6 I {; F# C# A7 R7 V2 p+ I1 }7 o
sync ();
$ y7 ^8 l! @. ?' b% j
save[i++] = *addr;
% }' x9 \) y6 E* d: l
sync ();
4 v% Y! R! e& L& v R4 B4 r+ D
*addr = ~cnt;
; j' ^; `4 y; M/ \
}
+ |, V/ }: m! l9 t& X i$ T3 r/ s
% { N# R! O: j3 ^9 n* m J
addr = base;
/ V3 y/ d0 Z4 I3 Z; D
sync ();
/ j3 N x- J6 z) J+ O
save
= *addr;
) v6 I w+ x' h8 j
sync ();
7 n! P2 U( |. y' C* C2 }7 z7 R- o
*addr = 0;
; E! q# ]0 t& R7 ?, R# @7 |
) _8 \9 I3 v* q: r) Z
sync ();
: }8 H# \& V9 H9 l! ? B
if ((val = *addr) != 0) {
! k- r0 T' _ M
/* Restore the original data before leaving the function.
) Y) B3 L2 s6 z( H+ }
*/
% _+ n0 n/ @" K8 \8 e$ U/ h
sync ();
. M; N+ z+ t3 ^7 C8 b( K7 Z5 B5 o
*addr = save
;
% {, Y1 U1 i2 V9 a: e7 C% ^4 A
for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
8 O, X) ^0 D3 R( w0 U
addr = base + cnt;
% h( z( S7 f6 u9 }/ G- O
sync ();
( C$ D, s( b4 {: Q
*addr = save[--i];
) d8 x2 ~8 A0 I
}
) H- z4 d' ?$ i
return (0);
8 Y3 @* p0 i; n! M: |! H* @
}
. N G/ K1 @( d) j( ]
8 w0 c4 `, h; K' H! n$ V+ m
for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
0 ]* }, Z/ L1 P" k* d$ z" C6 c
addr = base + cnt; /* pointer arith! */
' x8 J' F9 J# I, m8 K2 W
val = *addr;
0 i4 s3 W6 A$ s/ M- F% l' v
*addr = save[--i];
5 `) p6 K& K: v/ r
if (val != ~cnt) {
: g3 g, m! G# c% o; K( a' Q
size = cnt * sizeof (long);
3 q- j: v) t2 G1 |% [
/* Restore the original data before leaving the function.
# ]5 R# h# R& l- e5 S1 y
*/
( e a( H' F1 H
for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
* F7 ^( {; m s V9 H. t1 f
addr = base + cnt;
* o7 ^; r* W2 W+ Y6 \
*addr = save[--i];
, z. i) W5 M, X1 Y' H2 p
}
; @7 m6 i) _0 K# [4 W) t- t2 u
return (size);
Z0 [% h9 x9 e: J$ y4 W
}
k! i9 ]# D, s- ]7 ^
}
( M9 y. R& C# Y* Y: c; r0 v8 t! K
) y" I' i1 I8 U& J, D0 x3 E
return (maxsize);
! N4 Z5 T% ~, i/ \, k$ Z
}
3 X! \) d& q# `9 C: a2 V0 j
int dram_init(void)
( X5 {- H9 U' T% }& S7 G1 G
{
# h2 D1 Y2 E, Q5 T! S) X; H3 P
/* dram_init must store complete ramsize in gd->ram_size */
% ]! X4 M; V' ~1 Z
gd->ram_size = get_ram_size(
' F9 {* |4 b3 n/ P, R N
(void *)CONFIG_SYS_SDRAM_BASE,
' n. K6 ^0 d* Z: \3 C* O
CONFIG_MAX_RAM_BANK_SIZE);
- V. t+ B/ M& L) l6 a. N7 B
return 0;
. [8 C, V+ H% |! T7 v4 \
}
& z, j2 b9 o& z+ H! D1 J! B
2 Q6 ]$ ~/ W/ ?4 o; X; i7 ]: |( V
1 B5 d4 ?# j( v% i G
5 i& l a5 a' W/ J3 ^; o/ ~1 g( P9 o! n
+ g4 D, k: y" I4 v, }
FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！
1 I' z- _7 x; y' `0 s& ^7 N, l
3 R7 {* R- K5 j( N
" P( ^$ B3 I4 }0 f3 d
; N- N% ]0 P0 F: \; {7 O
欢迎光临 嵌入式开发者社区 (https://www.51ele.net/)
Powered by Discuz! X3.4