디바이스 드라이버 mmap에 대한 질문입니다.

블랙핀 BF533-EZKIT에서 개발중입니다.

비디오 디바이스를 열고 메모리 맵으로 주소를 얻어 오려고 하면 에러가 발생해서 이렇게 질문을 올립니다.

다음은 비디오 디바이스 파일인 bfin_ad7171fb.c의 메모리 맵 함수입니다.

bfin_mmap(struct fb_info *info, struct file *file, struct vm_area_struct * vma)
{
  /* we really dont need any map ... not sure how the smem_start will
     end up in the kernel
  */
	return((int)rgb_buffer) ;
}

다음은 응용 프로그램에서 mmap를 사용한 모습입니다.

screen_ptr = mmap(0, screen_height * screen_width * (bits_per_pixel/8), PROT_READ}PROT_WRITE, 0, screen_fd, 0);

입니다.

이 상태에서 실행하면 다음과 같은 메세지가 나옵니다.

에러 메세지는 mmap()를 사용할 때 발생합니다.

<4>Jan  1 04:24:42 kernel: Illegal use of supervisor resource 
<4>Jan  1 04:24:42 kernel:  - Attempted to use a Supervisor register or instruction from User mode. 
<4>Jan  1 04:24:42 kernel:  Supervisor resources are registers and instructions that are reserved 
<4>Jan  1 04:24:42 kernel:  for Supervisor use: Supervisor only registers, all MMRs, and Supervisor 
<4>Jan  1 04:24:42 kernel:  only instructions. 
<4>Jan  1 04:24:42 kernel:  
<4>Jan  1 04:24:42 kernel: CURRENT PROCESS: 
<4>Jan  1 04:24:42 kernel:  
<4>Jan  1 04:24:42 kernel: COMM=video_test PID=33 
<4>Jan  1 04:24:42 kernel: TEXT=01800044-01805ea4 DATA=01805ea8-018072b8 BSS=018072b8-0180a018 
<4>Jan  1 04:24:42 kernel: USER-STACK=0180ff78 
<4>Jan  1 04:24:42 kernel:  
<4>Jan  1 04:24:42 kernel: RETX: 018005f0; contents of [RETX-16...RETX+8[: 
<4>Jan  1 04:24:42 kernel: 0881 1769 3202 9345 2f66 0cc0 1b0b e14a  
<4>Jan  1 04:24:42 kernel: 0180 e10a 9f58 9110 3048 0881 1703 3202 X 
<4>Jan  1 04:24:42 kernel: 9345 2f00 3215 3248 e151 0180 3004 e111  
<4>Jan  1 04:24:42 kernel:  
<4>Jan  1 04:24:42 kernel: RETE:  00000000  RETN: 00000000  RETX: 018005f0  RETS: 01800ba6 
<4>Jan  1 04:24:42 kernel: IPEND: 0008  SYSCFG: 0036 
<4>Jan  1 04:24:42 kernel: SEQSTAT: 0000002e    SP: 0184ff24 
<4>Jan  1 04:24:42 kernel: R0: 0000020c    R1: 00000000    R2: fffffa5f    R3: 00000000 
<4>Jan  1 04:24:42 kernel: R4: 00000168    R5: 00000167    R6: fffffe99    R7: 00000000 
<4>Jan  1 04:24:42 kernel: P0: fffffa5f    P1: 00000000    P2: 01809f58    P3: 0180a004 
<4>Jan  1 04:24:42 kernel: P4: 0180a008    P5: 00ff0000    FP: 0180feb4 
<4>Jan  1 04:24:42 kernel: A0.w: 00000000    A0.x: 00000000    A1.w: 00000000    A1.x: 00000000 
<4>Jan  1 04:24:42 kernel: LB0: 018047f5  LT0: 018047f2  LC0: 00000000 
<4>Jan  1 04:24:42 kernel: LB1: 00000001  LT1: 00000000  LC1: 00000000 
<4>Jan  1 04:24:42 kernel: B0: fffffd32  L0: 00000000  M0: 00000000  I0: 00000000 
<4>Jan  1 04:24:42 kernel: B1: 00000000  L1: 00000000  M1: 00000000  I1: 01809f60 
<4>Jan  1 04:24:42 kernel: B2: 00000000  L2: 00000000  M2: 00000000  I2: 00000000 
<4>Jan  1 04:24:42 kernel: B3: 00000000  L3: 00000000  M3: 00000000  I3: 00000000 
<4>Jan  1 04:24:42 kernel:  
<4>Jan  1 04:24:42 kernel: USP: 0180feb4   ASTAT: 02000022 
<4>Jan  1 04:24:42 kernel:  
<4>Jan  1 04:24:42 last message repeated 1 time(s) 
<0>Jan  1 04:24:42 kernel: Stack from 0184fe78:<0> 
<4>Jan  1 04:24:42 kernel:        <0> 0180a008<0> 00004306<0> 00000001<0> 000dbf1c<0> ffffffff<0> 00000004<0> 00000000<0> 00030005<0> 
<4>Jan  1 04:24:42 kernel:        <0> 018059e6<0> 0180feb8<0> 00000000<0> 0002910e<0> 00613740<0> 00000001<0> 00000000<0> 00613e20<0> 
<4>Jan  1 04:24:42 kernel:        <0> 00000003<0> 0184fee8<0> 000291fa<0> 0184fee8<0> 00613740<0> fffffff7<0> 01807276<0> 00000001<0> 
<4>Jan  1 04:24:42 kernel:        <0> 000b8380<0> 00000003<0> 00000000<0> 0184fee8<0> 00000000<0> 00000000<0> 00000000<0> 000068ea<0> 
<4>Jan  1 04:24:42 kernel:        <0> 000291c4<0> 00000004<0> 00000100<0> ffffe000<0> 00000004<0> 0000675a<0> 00ff0000<0> 00000000<0> 
<4>Jan  1 04:24:42 kernel:        <0> 0000000b<0> 0180622f<0> 018059e6<0> 018005f0<0> 00000008<0> 0000002e<0> 00000000<0> 00000000<0> 
<4>Jan  1 04:24:42 kernel: Call Trace:<0> 
<4>Jan  1 04:24:42 kernel:  bfin_ad7171_fb Realeased 

도움 부탁 드립니다.