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
29uint32_t dos_mem = 0;		/* 0-1MB */
30uint32_t low_mem = 0;		/* 1-16MB */
31uint32_t high_mem = 0;		/* 16+ MB */
32
33#ifndef TEST
34
35static 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(&regs, 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, &regs, &regs);
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
74static inline void get_dos_mem(void)
75{
76    com32sys_t regs;
77
78    memset(&regs, 0, sizeof regs);
79    intcall(0x12, &regs, &regs);
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
84static inline int get_e801(void)
85{
86    int err;
87    com32sys_t regs;
88
89    memset(&regs, 0, sizeof regs);
90
91    regs.eax.w[0] = 0xe801;
92    intcall(0x15, &regs, &regs);
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
110static inline int get_88(void)
111{
112    com32sys_t regs;
113    int err;
114
115    memset(&regs, 0, sizeof regs);
116
117    regs.eax.b[1] = 0x88;
118    intcall(0x15, &regs, &regs);
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
132void 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
148void 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