1 /* ----------------------------------------------------------------------- *
2 *
3 * Copyright 2001-2008 H. Peter Anvin - All Rights Reserved
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, Inc., 53 Temple Place Ste 330,
8 * Boston MA 02111-1307, USA; either version 2 of the License, or
9 * (at your option) any later version; incorporated herein by reference.
10 *
11 * ----------------------------------------------------------------------- */
12
13 /*
14 * msetup.c
15 *
16 * Initialization code for memory-based disk
17 */
18
19 #include <stdint.h>
20 #ifdef TEST
21 # include <string.h>
22 # include <stdio.h>
23 #else
24 # include "memdisk.h"
25 # include "conio.h"
26 #endif
27 #include "e820.h"
28
29 uint32_t dos_mem = 0; /* 0-1MB */
30 uint32_t low_mem = 0; /* 1-16MB */
31 uint32_t high_mem = 0; /* 16+ MB */
32
33 #ifndef TEST
34
get_e820(void)35 static inline int get_e820(void)
36 {
37 struct e820_info {
38 uint64_t base;
39 uint64_t len;
40 uint32_t type;
41 } *buf = sys_bounce;
42 uint32_t copied;
43 int range_count = 0;
44 com32sys_t regs;
45
46 memset(®s, 0, sizeof regs);
47 memset(buf, 0, sizeof *buf);
48
49 do {
50 regs.eax.l = 0x0000e820;
51 regs.ecx.l = sizeof(*buf);
52 regs.edx.l = 0x534d4150;
53 regs.edi.w[0] = OFFS(buf);
54 regs.es = SEG(buf);
55
56 intcall(0x15, ®s, ®s);
57 copied = (regs.eflags.l & 1) ? 0 : regs.ecx.l;
58
59 if (regs.eax.l != 0x534d4150 || copied < 20)
60 break;
61
62 printf("e820: %08x%08x %08x%08x %d\n",
63 (uint32_t) (buf->base >> 32), (uint32_t) buf->base,
64 (uint32_t) (buf->len >> 32), (uint32_t) buf->len, buf->type);
65
66 insertrange(buf->base, buf->len, buf->type);
67 range_count++;
68
69 } while (regs.ebx.l);
70
71 return !range_count;
72 }
73
get_dos_mem(void)74 static inline void get_dos_mem(void)
75 {
76 com32sys_t regs;
77
78 memset(®s, 0, sizeof regs);
79 intcall(0x12, ®s, ®s);
80 insertrange(0, (uint64_t) ((uint32_t) regs.eax.w[0] << 10), 1);
81 printf(" DOS: %d K\n", regs.eax.w[0]);
82 }
83
get_e801(void)84 static inline int get_e801(void)
85 {
86 int err;
87 com32sys_t regs;
88
89 memset(®s, 0, sizeof regs);
90
91 regs.eax.w[0] = 0xe801;
92 intcall(0x15, ®s, ®s);
93
94 if (!(err = regs.eflags.l & 1)) {
95 if (regs.eax.w[0]) {
96 insertrange(0x100000, (uint64_t) ((uint32_t) regs.eax.w[0] << 10),
97 1);
98 }
99 if (regs.ebx.w[0]) {
100 insertrange(0x1000000, (uint64_t) ((uint32_t) regs.ebx.w[0] << 16),
101 1);
102 }
103
104 printf("e801: %04x %04x\n", regs.eax.w[0], regs.ebx.w[0]);
105 }
106
107 return err;
108 }
109
get_88(void)110 static inline int get_88(void)
111 {
112 com32sys_t regs;
113 int err;
114
115 memset(®s, 0, sizeof regs);
116
117 regs.eax.b[1] = 0x88;
118 intcall(0x15, ®s, ®s);
119
120 if (!(err = regs.eflags.l & 1)) {
121 if (regs.eax.w[0]) {
122 insertrange(0x100000, (uint64_t) ((uint32_t) regs.eax.w[0] << 10),
123 1);
124 }
125
126 printf(" 88: %04x\n", regs.eax.w[0]);
127 }
128
129 return err;
130 }
131
get_mem(void)132 void get_mem(void)
133 {
134 if (get_e820()) {
135 get_dos_mem();
136 if (get_e801()) {
137 if (get_88()) {
138 die("MEMDISK: Unable to obtain memory map\n");
139 }
140 }
141 }
142 }
143
144 #endif /* TEST */
145
146 #define PW(x) (1ULL << (x))
147
parse_mem(void)148 void parse_mem(void)
149 {
150 struct e820range *ep;
151
152 dos_mem = low_mem = high_mem = 0;
153
154 /* Derive "dos mem", "high mem", and "low mem" from the range array */
155 for (ep = ranges; ep->type != -1U; ep++) {
156 if (ep->type == 1) {
157 /* Only look at memory ranges */
158 if (ep->start == 0) {
159 if (ep[1].start > PW(20))
160 dos_mem = PW(20);
161 else
162 dos_mem = ep[1].start;
163 }
164 if (ep->start <= PW(20) && ep[1].start > PW(20)) {
165 if (ep[1].start > PW(24))
166 low_mem = PW(24) - PW(20);
167 else
168 low_mem = ep[1].start - PW(20);
169 }
170 if (ep->start <= PW(24) && ep[1].start > PW(24)) {
171 if (ep[1].start > PW(32))
172 high_mem = PW(32) - PW(24);
173 else
174 high_mem = ep[1].start - PW(24);
175 }
176 }
177 }
178 }
179