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
% J8 t, s( o# H* t
核心板2：DDR2 256M Byte NAND FLASH 8G bit
7 ^! F/ b' V/ P3 t
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？
+ j/ V, A& S+ ] f( A+ e
* u2 Y6 b; D$ g+ {( h
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？
6 K9 P! {, V+ `8 n' F# _
o, L5 e4 P! k$ j0 Z! J) e% r5 a- {1 O
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：
& y( g- p' a) U! y: }0 Z: J
/*
* n, k; O0 Y- G' z' G
* Check memory range for valid RAM. A simple memory test determines
' v; ~4 b6 g& e! j$ D
* the actually available RAM size between addresses `base' and
) ?4 ?. {. X& y; w4 p" A
* `base + maxsize'.
/ E# P# h7 R" Q( e9 w! l
*/
' o& z) j3 N" f; x% v" S
long get_ram_size(long *base, long maxsize)
5 l7 m. S& h2 V
{
& W6 M0 n C% V5 `
volatile long *addr;
! z6 J+ G$ j% y7 m" s
long save[32];
0 z+ n7 `7 G' \" F% E# h, a
long cnt;
) n: ]. F- I) {& Z# d+ X1 L
long val;
- S) z9 L3 N& E- a& j% ?+ `
long size;
* A! q6 _) q1 s3 s6 j# _% @3 Q! D
int i = 0;
- G2 Q) W I# X- `' J, \* L% z, {8 l
6 W: J2 h% [% n f
for (cnt = (maxsize / sizeof (long)) >> 1; cnt > 0; cnt >>= 1) {
$ A4 x' l8 s8 f: ?! Z g
addr = base + cnt; /* pointer arith! */
$ F6 L/ e: `! ?; {
sync ();
+ S4 Y" H+ s5 P& b
save[i++] = *addr;
; G6 }8 J: o! }) C7 u) b8 }* J
sync ();
7 e. @! z' K1 v* | m. K' i# e
*addr = ~cnt;
# ]) j% E+ X p; g% i
}
4 }. y; j& G* v' K1 Z Q
" ?- ?4 l* [! `8 ^) h' K
addr = base;
. B3 p& b2 {7 t0 V) m7 e8 e1 J) V
sync ();
! T- M+ J) D2 ]6 ]* T; z
save
= *addr;
( e2 p! g' @/ a- m2 u6 o
sync ();
1 q, F; d0 {: }: c. E: y
*addr = 0;
& N$ z6 ^% z i% R; b$ y/ p4 B! i
4 K. _ _/ |2 Y( W# \; u4 {4 c% [
sync ();
; j$ H2 V; R: e+ V1 o
if ((val = *addr) != 0) {
8 ^9 A* l9 C3 `) M( U! a. H' O
/* Restore the original data before leaving the function.
: _; y ]" \' A$ ?- j
*/
; D8 d# C! {5 `. T( T W5 R; P+ T
sync ();
. m" ~5 y2 Y( } [, S
*addr = save
;
$ |6 M0 r C) w
for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
( T# s; `+ M% V' x, _' b$ n) ?
addr = base + cnt;
1 `+ d2 p; J2 A$ @7 \5 e9 A
sync ();
' G# j& F2 m3 Q' K# E: h( S; i
*addr = save[--i];
6 O0 h) R7 k. q2 d. G
}
# w6 C: i2 i, m3 e! G/ Z
return (0);
+ M7 `! u( M6 N# {/ g
}
2 c, t- D" @: J6 D9 Z
5 S8 b- m% w0 Y; H2 F
for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
0 N- P a$ @) z$ H1 c+ ^% J
addr = base + cnt; /* pointer arith! */
6 Z2 d: i) }7 D8 C% f
val = *addr;
" U+ Z0 w6 n( J6 x& t& ]
*addr = save[--i];
9 ]2 F5 |7 y+ Y4 i: \- G
if (val != ~cnt) {
' D: [) n5 E5 [+ ^
size = cnt * sizeof (long);
% e$ q: j( [& L! d1 Z& l
/* Restore the original data before leaving the function.
: \; E# L/ b& p. u) M0 b" v6 R
*/
7 G- C! c- T H6 r$ G: @2 r0 d x* p2 d0 [
for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
( h/ M0 [0 [ T
addr = base + cnt;
+ h9 }8 \ o# |
*addr = save[--i];
; R; e9 R3 ]* V& `
}
3 H7 P- r6 ?8 z8 j
return (size);
- c$ K: T: o$ l7 N" g6 E
}
' E' [4 I6 ?/ d( ]; o% e/ L) C$ J
}
: O/ }7 C" t& V) N) P
- U& ~+ k k" ~* C
return (maxsize);
) H- M% V+ W t3 ~
}
# {, I: t9 a' R: o
int dram_init(void)
9 I4 i" d( E$ P2 h
{
$ }" q7 t' p- l$ I3 Q6 K( d
/* dram_init must store complete ramsize in gd->ram_size */
7 C( x o1 w( ~* L$ K# F8 @, ?
gd->ram_size = get_ram_size(
. A( t3 A* z8 y! u' ~, N" j3 ]1 h
(void *)CONFIG_SYS_SDRAM_BASE,
5 o+ W& a. a% `" j8 y3 _
CONFIG_MAX_RAM_BANK_SIZE);
0 f8 A/ ~0 U% d& v% Y( K
return 0;
% H; d) B2 @4 A/ R! u
}
# ]! m. [# Q3 |% k# I9 N: C6 e4 ^
% \# d! w7 {- P5 j, F# X
! ~9 h, t; E8 [& W6 g# ^
8 D; j2 L# e+ l# E* ]$ Y
* E& T1 ^0 |8 y0 X
FLASH是通过检查FLASH内部的ID识别容量，希望对您有帮助！
0 g; c3 c- ~5 E) h* ?
0 B6 p( L+ w% k B5 u- u
" _* j: }& h0 e$ q- Z5 M; j
z) a+ g3 }1 R: ]; b1 \) g
欢迎光临 嵌入式开发者社区 (https://www.51ele.net/)
Powered by Discuz! X3.4