jens
ed483b2e03
Committed on the Free edition of March Hare Software CVSNT Server. Upgrade to CVS Suite for more features and support: http://march-hare.com/cvsnt/ git-svn-id: http://moon:8086/svn/vhdl/trunk@786 cc03376c-175c-47c8-b038-4cd826a8556b
87 lines
1.2 KiB
C
87 lines
1.2 KiB
C
#include <stdio.h>
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#include "libsys.h"
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#include "xcpt.h"
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/* 10 digits + 1 sign + 1 trailing nul */
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static char itoa_buf[12];
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char *itoa(int i)
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{
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char *pos = itoa_buf + sizeof(itoa_buf) - 1;
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unsigned int u;
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int negative = 0;
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if (i < 0)
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{
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negative = 1;
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u = ((unsigned int)(-(1+i))) + 1;
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}
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else
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{
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u = i;
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}
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*pos = 0;
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do
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{
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*--pos = '0' + (u % 10);
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u /= 10;
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} while (u);
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if (negative)
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{
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*--pos = '-';
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}
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return pos;
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}
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int syscalls_handler(struct xcptcontext * xcp)
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{
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int syscall_code;
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char *pStr, buf[33];
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syscall_code = xcp->regs[2];
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switch(syscall_code)
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{
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case 1: // print integer
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sputs(itoa(xcp->regs[4]));
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break;
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case 4: // print string
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pStr = (char*)xcp->regs[4];
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sputs(pStr);
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break;
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case 5: // read integer
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pStr = fgets(buf, sizeof(buf), stdin);
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xcp->regs[2] = atoi(pStr);
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break;
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case 8: // read string
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pStr = (char*)xcp->regs[4];
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fgets(pStr, xcp->regs[5], stdin);
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break;
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case 10: // exit
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_exit(0);
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break;
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default:
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sputs("\nUnknown syscall (");print_word(syscall_code);sputs(") at ");print_word(xcp->epc);sputs("\n");
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break;
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}
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xcp->epc += 4; // set return address to instruction after syscall
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return 0;
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}
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void syscalls_init(void)
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{
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xcpt_register(Syscall, syscalls_handler);
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}
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