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#include <com32.h>
#include <stdarg.h>
#define NULL ((void *)0)
int printf(const char *, ...);
int putchar(int);
static inline void memset(void *buf, int ch, unsigned int len)
{
asm volatile ("cld; rep; stosb":"+D" (buf), "+c"(len):"a"(ch):"memory");
}
static void strcpy(char *dst, const char *src)
{
while (*src)
*dst++ = *src++;
*dst = '\0';
}
static void printregs(const com32sys_t * r)
{
printf("eflags = %08x ds = %04x es = %04x fs = %04x gs = %04x\n"
"eax = %08x ebx = %08x ecx = %08x edx = %08x\n"
"ebp = %08x esi = %08x edi = %08x esp = %08x\n",
r->eflags.l, r->ds, r->es, r->fs, r->gs,
r->eax.l, r->ebx.l, r->ecx.l, r->edx.l,
r->ebp.l, r->esi.l, r->edi.l, r->_unused_esp.l);
}
int __start(void)
{
unsigned int ax, cx, si, t;
com32sys_t inreg, outreg;
char *p;
/* Test null system call */
inreg.eflags.l = 0xffffffff;
inreg.eax.l = 0x11110000;
inreg.ecx.l = 0x22222222;
inreg.edx.l = 0x33333333;
inreg.ebx.l = 0x44444444;
inreg.ebp.l = 0x55555555;
inreg.esi.l = 0x66666666;
inreg.edi.l = 0x77777777;
inreg.ds = 0xaaaa;
inreg.es = 0xbbbb;
inreg.fs = 0xcccc;
inreg.gs = 0xdddd;
printregs(&inreg);
__com32.cs_intcall(0x22, &inreg, &outreg);
printregs(&outreg);
printf("----\n");
memset(&inreg, 0, sizeof inreg);
memset(&outreg, 0, sizeof outreg);
strcpy(__com32.cs_bounce, "test.txt");
inreg.eax.w[0] = 0x0006; // Open file
inreg.esi.w[0] = OFFS(__com32.cs_bounce);
inreg.es = SEG(__com32.cs_bounce);
printregs(&inreg);
__com32.cs_intcall(0x22, &inreg, &outreg);
printregs(&outreg);
printf("----\n");
si = outreg.esi.w[0]; /* File handle */
cx = outreg.ecx.w[0]; /* Block size */
ax = outreg.eax.l; /* File length */
while (si) {
/* We can only read 64K per call */
t = (ax > 65536) ? 65536 / cx : (ax + cx - 1) / cx;
memset(&inreg, 0, sizeof inreg);
inreg.esi.w[0] = si;
inreg.ecx.w[0] = t; /* Block count */
inreg.eax.w[0] = 0x0007; // Read file
inreg.ebx.w[0] = OFFS(__com32.cs_bounce);
inreg.es = SEG(__com32.cs_bounce);
printregs(&inreg);
__com32.cs_intcall(0x22, &inreg, &outreg);
printregs(&outreg);
printf("----\n");
si = outreg.esi.w[0];
/* Print the buffer */
t = (ax < 65536) ? ax : 65536;
p = __com32.cs_bounce;
while (t) {
putchar(*p++);
t--;
ax--;
}
}
return 0;
}
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