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Annotation of Gnu-Mach/i386/dos/dos_write.c, revision 1.1.1.1

1.1       root        1: /* 
                      2:  * Copyright (c) 1995-1994 The University of Utah and
                      3:  * the Computer Systems Laboratory at the University of Utah (CSL).
                      4:  * All rights reserved.
                      5:  *
                      6:  * Permission to use, copy, modify and distribute this software is hereby
                      7:  * granted provided that (1) source code retains these copyright, permission,
                      8:  * and disclaimer notices, and (2) redistributions including binaries
                      9:  * reproduce the notices in supporting documentation, and (3) all advertising
                     10:  * materials mentioning features or use of this software display the following
                     11:  * acknowledgement: ``This product includes software developed by the
                     12:  * Computer Systems Laboratory at the University of Utah.''
                     13:  *
                     14:  * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
                     15:  * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
                     16:  * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
                     17:  *
                     18:  * CSL requests users of this software to return to [email protected] any
                     19:  * improvements that they make and grant CSL redistribution rights.
                     20:  *
                     21:  *      Author: Bryan Ford, University of Utah CSL
                     22:  */
                     23: 
                     24: #include <unistd.h>
                     25: #include <errno.h>
                     26: 
                     27: #include "dos_io.h"
                     28: #include "vm_param.h"
                     29: 
                     30: int dos_write(dos_fd_t fd, const void *buf, vm_size_t size, vm_size_t *out_actual)
                     31: {
                     32:        int err;
                     33:        int actual = 0;
                     34:        struct real_call_data real_call_data;
                     35:        vm_offset_t dos_buf_phys = (vm_offset_t)kvtophys(dos_buf);
                     36: 
                     37:        assert(dos_buf); assert(dos_buf_phys);
                     38:        assert(dos_buf_phys < 0x100000);
                     39: 
                     40:        dos_init_rcd(&real_call_data);
                     41: 
                     42:        while (size > 0)
                     43:        {
                     44:                int little_size = size;
                     45:                int little_actual;
                     46: 
                     47:                if (little_size > DOS_BUF_SIZE)
                     48:                        little_size = DOS_BUF_SIZE;
                     49: 
                     50:                /* XXX don't copy if buf is <1MB */
                     51:                memcpy(dos_buf, buf, little_size);
                     52: 
                     53:                real_call_data.eax = 0x4000;
                     54:                real_call_data.ebx = fd;
                     55:                real_call_data.ecx = little_size;
                     56:                real_call_data.ds = dos_buf_phys >> 4;
                     57:                real_call_data.edx = dos_buf_phys & 15;
                     58:                real_int(0x21, &real_call_data);
                     59:                if (err = dos_check_err(&real_call_data))
                     60:                        return err;
                     61:                little_actual = real_call_data.eax & 0xffff;
                     62:                assert(little_actual <= little_size);
                     63: 
                     64:                buf += little_actual;
                     65:                size -= little_actual;
                     66:                actual += little_actual;
                     67: 
                     68:                if (little_actual < little_size)
                     69:                        break;
                     70:        }
                     71: 
                     72:        *out_actual = actual;
                     73:        return 0;
                     74: }
                     75: 

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