(2006-08-06) rescue-bootcd

extra/syslinux-3.09/sample/filetest.c

@@ -0,0 +1,98 @@
+#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.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;
+}