' D5 U$ P# M+ ovoid read_MSG_buffer(pRX_MSG_PROTOCOL pshreRAM); " t; C' r* y. T+ O, K+ {unsigned int count_copy = 0; z- A! j9 B0 s* O6 U/ \8 Z. E7 ^; j, _; s
/ `1 O( q% t/ q$ r8 K! Bint main()) ~0 ]; N) F; ~! f! R! F
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pRX_MSG_PROTOCOL pshreRAM = NULL; # H* V- }5 @/ |: a$ M: ^5 P pshreRAM = (pRX_MSG_PROTOCOL)SHAER_RAM_BASE_ADDR;/ s# A+ m. F! G1 m3 G
! @+ x- u7 Y. m" J while(1)1 N* V/ K$ y9 H+ |/ ?; a( v
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read_MSG_buffer(pshreRAM);8 D2 E e' m1 p. f: j8 k
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} 1 I7 A2 C5 [) | ) N4 M7 h- r- D# Ivoid read_MSG_buffer(pRX_MSG_PROTOCOL pshreRAM) ' C4 C- B- j3 P" D c$ L{ * t- M' }# ]" Q& `" W( T, _+ u RX_MSG_PROTOCOL buf;% g& t* ?2 P" z, v0 Q
! |( K, m& i* C* e buf.a = pshreRAM->a; ( f' p- a) u/ }$ m buf.b = pshreRAM->b; # C/ y z7 }% I buf.packet_cout = pshreRAM->packet_cout;- O% t! R t, u& J8 y: v
+ @, T: R+ [5 t8 _; u5 t% H if(buf.packet_cout != count_copy) ' S4 H( h) k+ _7 f g {+ s$ I/ Q' P( ~- G8 S
printf("a is %d\n", buf.a);5 r0 H4 M" i& k3 n# }! j; z
printf("b is %d\n", buf.b); / k+ U! m _; L+ ]/ @% r$ { printf("count is %d\n", buf.packet_cout); # t4 B& a& i+ Z, v4 y# \1 O count_copy = buf.packet_cout; ( \! U; v3 H7 {: M+ v6 L9 Y/ Q% I( l } ) c0 ^% j0 W. q4 ] else ' r8 X2 M4 @4 j! v { ( s$ D0 w5 l8 u. i/ z( A/ @! t printf("No effective message!");+ }4 j, t$ w/ u6 g8 b1 a B
} - L4 N7 q7 t8 J$ A; ^" j} ) Z" C2 K& Q& U7 X5 a1 A% H" E , W7 m3 [6 i/ A 5 `3 D( z7 H$ w+ X4 T/ F* K但是出现segmentation fault的问题,这是什么原因啊???我在DSP端烧写了一段小程序,向共享区0x80000000位置写入数据,用CCS 测试发现写入成功。 A7 g. P! y3 N使用下面代码,对内存使用了mmap函数后:( b' V' _9 O( Q/ f& k% D
#include <stdio.h>2 I5 A G$ C! K K
#include <unistd.h> Y9 O4 ? r- W% x$ O
#include <sys/mman.h>: }0 Z$ |( k2 O: o- r! c: t
#include <sys/types.h>5 b- E/ d/ f( |
#include <fcntl.h>* a: x1 g# c2 m
- o! c d) h8 s' N5 ]#define SHAER_RAM_BASE_ADDR (0x80000000) * d& f' t9 s7 D6 C2 a! f: B2 P! l#define SHAER_RAM_SIZE (0x20000) $ ]4 u- s9 K* {- l+ x$ p- |& m2 W F9 w( x7 w' F
typedef struct / {( J( J1 _ ~1 U7 |5 t8 Z# l{ : _1 T6 n1 d' w) L! ?$ s" G4 ` unsigned int a;$ f ^+ Q9 H; x, r/ m! r
unsigned int b; , o/ L% `6 M7 i* {9 j0 Z+ ? unsigned int packet_cout; % s; y0 ]0 O2 x" x; Y& H}RX_MSG_PROTOCOL, *pRX_MSG_PROTOCOL; , G9 l0 [. \" a- G9 ?3 K) ?6 t7 Y0 v9 @. J8 _
void read_MSG_buffer(int *baseaddr); 0 }% }1 U" \/ m8 K; Bunsigned int count_copy = 0; / h( L% K- d5 `0 P' S5 I3 @2 A/ M& I, O
int main()2 g( ?& ?; y' z% j1 R6 j8 Z3 I1 L; D
{ 2 ?* p/ C i3 G6 A int fd; " m( @6 O% w: h0 E int *mem = NULL;! X$ m+ [4 n6 [0 c4 M
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if((fd = open("/dev/mem", O_RDWR)) <0) 4 G3 G9 H: _4 J' e- x3 W { 7 g |2 k0 C- X4 l/ D/ S perror("open error"); ' t: g; q6 _) q* z& |) F- a* Q return -1;: ^3 I# d* V) P, w. t c5 W
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mem = mmap((void *)SHAER_RAM_BASE_ADDR, SHAER_RAM_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);: {' L* C9 \' t8 h
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while(1) ; t% w( F% X# _: H* `0 q {# j; X( ~& e: ]. }/ s( m
read_MSG_buffer(mem); # {+ [* R8 {1 |( o! D5 c } 1 \# @. R+ C( Q: V' n
} . i4 @/ F. q2 y3 V4 O/ b0 Y3 S" r , m' i0 H* U0 \1 A2 R6 x t1 Ovoid read_MSG_buffer(int *baseaddr) : ]- B% O+ _8 c: ~8 e3 K{' }# { ?- u& e: S1 c5 P( G
pRX_MSG_PROTOCOL pshreRAM = NULL;+ s2 [! v9 g5 Q7 k
! E% L9 Y* C( P2 |# i6 R pshreRAM = (pRX_MSG_PROTOCOL)baseaddr; / G$ t/ W( n6 j) b : b3 Z+ M8 M+ n* _' M, N if(pshreRAM->packet_cout != count_copy)4 A1 n2 a- L8 S7 p, u
{: m3 c0 t7 m8 R% _
printf("a is %d\n", pshreRAM->a); / b: K/ n$ b: E1 ]2 k! D$ b printf("b is %d\n", pshreRAM->b); 2 B! r, Z+ V' f- V; l; V printf("count is %d\n", pshreRAM->packet_cout); $ T+ {* s- a+ E! F: i O: B6 j count_copy = pshreRAM->packet_cout;8 q- C. U0 G# }# ?6 L
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else " b1 l4 V& ]" }0 P! H2 t) W- v {1 Q, y& K" b* Y2 Y) V% N
printf("No effective message!\n");- R3 G( ] q- H+ e7 E4 n1 W0 V
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} & _% A4 i# u- H- p: O( e8 a2 I- r/ O$ m& B1 ? B; ]2 L
没有出现segmentation fault这个错误,但是读出来的数据均为0。这该怎样解决啊???主要问题还是在Linux系统下,OMAPL138是否可以直接访问映射地址???该怎样实现???8 y% H2 \$ T2 b2 ~! n
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