Very first cut at a klibc-derived C library for com32

1 files changed, 79 insertions, 0 deletions

diff --git a/com32/lib/sys/open.c b/com32/lib/sys/open.c
new file mode 100644
index 00000000..3f84e5f7
--- /dev/null
+++ b/com32/lib/sys/open.c
@@ -0,0 +1,79 @@
+#ident "$Id$"
+/* ----------------------------------------------------------------------- *
+ *   
+ *   Copyright 2003 H. Peter Anvin - All Rights Reserved
+ *
+ *   Permission is hereby granted, free of charge, to any person
+ *   obtaining a copy of this software and associated documentation
+ *   files (the "Software"), to deal in the Software without
+ *   restriction, including without limitation the rights to use,
+ *   copy, modify, merge, publish, distribute, sublicense, and/or
+ *   sell copies of the Software, and to permit persons to whom
+ *   the Software is furnished to do so, subject to the following
+ *   conditions:
+ *   
+ *   The above copyright notice and this permission notice shall
+ *   be included in all copies or substantial portions of the Software.
+ *   
+ *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ *   OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * ----------------------------------------------------------------------- */
+
+#include <errno.h>
+#include <com32.h>
+#include <string.h>
+#include "file.h"
+
+int open(const char *pathname, int flags, mode_t mode)
+{
+  com32sys_t regs;
+  int fd;
+  struct file_info *fp;
+  
+  if ( flags ) {
+    errno = EINVAL;
+    return -1;
+  }
+
+  for ( fd = 0, fp = __file_info ; fd < NFILES ; fd++, fp++ )
+    if ( fp->blocklg2 == 0 )
+      break;
+
+  if ( fd >= NFILES ) {
+    errno = EMFILE;
+    return -1;
+  }
+
+  strlcpy(__com32.cs_bounce, pathname, __com32.cs_bounce_size);
+
+  regs.eax.w[0] = 0x0006;
+  regs.esi.w[0] = OFFS(__com32.cs_bounce);
+  regs.es = SEG(__com32.cs_bounce);
+
+  __com32.cs_intcall(0x22, &regs, &regs);
+  
+  if ( (regs.eflags.l & EFLAGS_CF) || regs.esi.w[0] == 0 ) {
+    errno = ENOENT;
+    return -1;
+  }
+
+  {
+    uint16_t blklg2;
+    asm("bsrw %1,%0" : "=r" (blklg2) : "rm" (regs.ecx.w[0]));
+    fp->blocklg2 = blklg2;
+  }
+  fp->length    = regs.eax.l;
+  fp->filedes   = regs.esi.w[0];
+  fp->offset    = 0;
+  fp->nbytes    = 0;
+  fp->datap     = fp->buf;
+
+  return fd;
+}