1 /* ----------------------------------------------------------------------- *
2 *
3 * Copyright 2004-2008 H. Peter Anvin - All Rights Reserved
4 * Copyright 2013 Intel Corporation; author: H. Peter Anvin
5 *
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
13 * conditions:
14 *
15 * The above copyright notice and this permission notice shall
16 * be included in all copies or substantial portions of the Software.
17 *
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.
26 *
27 * ----------------------------------------------------------------------- */
28
29 /*
30 * argv.c
31 *
32 * Parse the MS-DOS command line into argc and argv (argc is return value.)
33 * memptr points to available memory.
34 */
35
36 #include <inttypes.h>
37 #include <stddef.h>
38 #include <stdbool.h>
39 #include "mystuff.h"
40
41 #define ALIGN_UP(p,t) ((t *)(((uintptr_t)(p) + (sizeof(t)-1)) & ~(sizeof(t)-1)))
42
43 extern char __heap_start[];
44 void *__mem_end = &__heap_start; /* Global variable for use by malloc() */
45
__parse_argv(char *** argv)46 int __parse_argv(char ***argv)
47 {
48 char *mem = __mem_end;
49 const char *str, *p;
50 char *q = mem;
51 char c, *r;
52 char **arg;
53 bool wasspace;
54 int argc;
55 int len;
56 size_t offs;
57 int nulls;
58 uint16_t nstr;
59
60 /* Find and copy argv[0] after the environment block */
61 set_fs(_PSP.environment);
62 offs = 0;
63 nulls = 0;
64 do {
65 if (get_8_fs(offs++) == '\0')
66 nulls++;
67 else
68 nulls = 0;
69 } while (nulls < 2);
70
71 nstr = get_16_fs(offs);
72 offs += 2;
73
74 /* Copy the null-terminated filename string */
75 if (nstr >= 1) {
76 while ((c = get_8_fs(offs++)))
77 *q++ = c;
78 }
79 *q++ = '\0';
80
81 /* Now for the command line tail... */
82
83 len = _PSP.cmdlen;
84 str = _PSP.cmdtail;
85 argc = 1;
86 wasspace = true;
87
88 /* Copy the command tail, turning whitespace runs into nulls */
89 for (p = str;; p++) {
90 if (!len || *p <= ' ') {
91 if (!wasspace) {
92 wasspace = true;
93 *q++ = '\0';
94 }
95 } else {
96 if (wasspace) {
97 argc++;
98 wasspace = false;
99 }
100 *q++ = *p;
101 }
102
103 /* This test is AFTER we have processed the end byte;
104 we treat it as a whitespace character so it terminates
105 the last argument */
106 if (!len--)
107 break;
108 }
109
110 /* Now create argv */
111 arg = ALIGN_UP(q, char *);
112 *argv = arg;
113 *arg++ = mem; /* argv[0] */
114
115 q--; /* Point q to terminal character */
116 for (r = mem; r < q; r++) {
117 if (*r == '\0') {
118 *arg++ = r + 1;
119 }
120 }
121
122 *arg++ = NULL; /* Null pointer at the end */
123 __mem_end = arg; /* End of memory we used */
124
125 return argc;
126 }
127