1 #ident "$Id: fileread.c,v 1.2 2004/11/23 23:43:02 hpa Exp $"
2 /* ----------------------------------------------------------------------- *
4 * Copyright 2004 H. Peter Anvin - All Rights Reserved
6 * Permission is hereby granted, free of charge, to any person
7 * obtaining a copy of this software and associated documentation
8 * files (the "Software"), to deal in the Software without
9 * restriction, including without limitation the rights to use,
10 * copy, modify, merge, publish, distribute, sublicense, and/or
11 * sell copies of the Software, and to permit persons to whom
12 * the Software is furnished to do so, subject to the following
15 * The above copyright notice and this permission notice shall
16 * be included in all copies or substantial portions of the Software.
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
20 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
21 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
22 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
23 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
24 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
25 * OTHER DEALINGS IN THE SOFTWARE.
27 * ----------------------------------------------------------------------- */
41 ssize_t __file_read(struct file_info *fp, void *buf, size_t count)
43 com32sys_t ireg, oreg;
48 memset(&ireg, 0, sizeof ireg);
49 ireg.eax.w[0] = 0x0007; /* Read file */
50 ireg.esi.w[0] = OFFS(__com32.cs_bounce);
51 ireg.es = SEG(__com32.cs_bounce);
54 if ( fp->i.nbytes == 0 ) {
55 if ( fp->i.offset >= fp->i.length || !fp->i.filedes )
56 return n; /* As good as it gets... */
58 ireg.esi.w[0] = fp->i.filedes;
59 ireg.ecx.w[0] = MAXBLOCK >> fp->i.blocklg2;
61 __intcall(0x22, &ireg, &oreg);
63 if ( oreg.eflags.l & EFLAGS_CF ) {
68 fp->i.filedes = ireg.esi.w[0];
69 fp->i.nbytes = min(fp->i.length-fp->i.offset, (unsigned)MAXBLOCK);
70 fp->i.datap = fp->i.buf;
71 memcpy(fp->i.buf, __com32.cs_bounce, fp->i.nbytes);
74 ncopy = min(count, fp->i.nbytes);
75 memcpy(bufp, fp->i.datap, ncopy);
81 fp->i.offset += ncopy;
82 fp->i.nbytes -= ncopy;