40 lines
591 B
C
Executable File
40 lines
591 B
C
Executable File
#include <stdio.h>
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#include <stdlib.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <sys/mman.h>
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#include <string.h>
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int main(int argc, char * argv[])
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{
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int fd;
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char *start;
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int i;
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char buf[32];
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fd = open("/dev/vfb0", O_RDWR);
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if (fd == -1)
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goto fail;
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start = mmap(NULL, 32, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
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if (start == MAP_FAILED)
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goto fail;
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for (i = 0; i < 26; i++)
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*(start + i) = 'a' + i;
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*(start + i) = '\0';
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if (read(fd, buf, 27) == -1)
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goto fail;
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puts(buf);
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munmap(start, 32);
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return 0;
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fail:
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perror("mmap test");
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exit(EXIT_FAILURE);
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}
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