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1 /* |
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2 * MIPS o32 Linux syscall example |
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3 * |
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4 * http://www.linux-mips.org/wiki/RISC/os |
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5 * http://www.linux-mips.org/wiki/MIPSABIHistory |
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6 * http://www.linux.com/howtos/Assembly-HOWTO/mips.shtml |
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7 * |
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8 * mipsel-linux-gcc -nostdlib -mno-abicalls -fno-PIC -mabi=32 \ |
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9 * -O2 -static -o hello-mips hello-mips.c |
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10 * |
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11 */ |
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12 #define __NR_SYSCALL_BASE 4000 |
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13 #define __NR_exit (__NR_SYSCALL_BASE+ 1) |
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14 #define __NR_write (__NR_SYSCALL_BASE+ 4) |
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15 |
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16 static inline void exit1(int status) |
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17 { |
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18 register unsigned long __a0 asm("$4") = (unsigned long) status; |
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19 |
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20 __asm__ __volatile__ ( |
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21 " .set push \n" |
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22 " .set noreorder \n" |
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23 " li $2, %0 \n" |
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24 " syscall \n" |
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25 " .set pop " |
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26 : |
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27 : "i" (__NR_exit), "r" (__a0) |
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28 : "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24", |
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29 "memory"); |
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30 } |
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31 |
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32 static inline int write(int fd, const char *buf, int len) |
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33 { |
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34 register unsigned long __a0 asm("$4") = (unsigned long) fd; |
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35 register unsigned long __a1 asm("$5") = (unsigned long) buf; |
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36 register unsigned long __a2 asm("$6") = (unsigned long) len; |
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37 register unsigned long __a3 asm("$7"); |
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38 unsigned long __v0; |
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39 |
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40 __asm__ __volatile__ ( |
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41 " .set push \n" |
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42 " .set noreorder \n" |
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43 " li $2, %2 \n" |
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44 " syscall \n" |
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45 " move %0, $2 \n" |
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46 " .set pop " |
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47 : "=r" (__v0), "=r" (__a3) |
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48 : "i" (__NR_write), "r" (__a0), "r" (__a1), "r" (__a2) |
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49 : "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24", |
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50 "memory"); |
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51 |
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52 /* if (__a3 == 0) */ |
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53 return (int) __v0; |
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54 /* |
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55 errno = __v0; |
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56 return -1; |
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57 */ |
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58 } |
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59 |
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60 void __start(void) |
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61 { |
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62 write (1, "Hello, World!\n", 14); |
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63 exit1 (42); |
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64 } |