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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 <mach/machine/code16.h>
25: #include <mach/machine/vm_types.h>
26: #include <mach/machine/far_ptr.h>
27: #include <mach/machine/proc_reg.h>
28:
29: #include "i16_bios.h"
30: #include "phys_mem.h"
31: #include "vm_param.h"
32: #include "debug.h"
33:
34:
35: static vm_offset_t ext_mem_phys_free_mem;
36: static vm_size_t ext_mem_phys_free_size;
37:
38:
39: CODE32
40:
41: int ext_mem_collect(void)
42: {
43: if (ext_mem_phys_free_mem)
44: {
45: phys_mem_add(ext_mem_phys_free_mem, ext_mem_phys_free_size);
46: ext_mem_phys_free_mem = 0;
47: }
48: }
49:
50: CODE16
51:
52: void i16_ext_mem_check()
53: {
54: vm_offset_t ext_mem_top, ext_mem_bot;
55: unsigned short ext_mem_k;
56:
57: /* Find the top of available extended memory. */
58: asm volatile("
59: int $0x15
60: jnc 1f
61: xorw %%ax,%%ax
62: 1:
63: " : "=a" (ext_mem_k)
64: : "a" (0x8800));
65: ext_mem_top = 0x100000 + (vm_offset_t)ext_mem_k * 1024;
66:
67: /* XXX check for >16MB memory using function 0xc7 */
68:
69: ext_mem_bot = 0x100000;
70:
71: /* Check for extended memory allocated bottom-up: method 1.
72: This uses the technique (and, loosely, the code)
73: described in the VCPI spec, version 1.0. */
74: if (ext_mem_top > ext_mem_bot)
75: {
76: asm volatile("
77: pushw %%es
78:
79: xorw %%ax,%%ax
80: movw %%ax,%%es
81: movw %%es:0x19*4+2,%%ax
82: movw %%ax,%%es
83:
84: movw $0x12,%%di
85: movw $7,%%cx
86: rep
87: cmpsb
88: jne 1f
89:
90: xorl %%edx,%%edx
91: movb %%es:0x2e,%%dl
92: shll $16,%%edx
93: movw %%es:0x2c,%%dx
94:
95: 1:
96: popw %%es
97: " : "=d" (ext_mem_bot)
98: : "d" (ext_mem_bot),
99: "S" ((unsigned short)(vm_offset_t)"VDISK V")
100: : "eax", "ecx", "esi", "edi");
101: }
102: i16_assert(ext_mem_bot >= 0x100000);
103:
104: /* Check for extended memory allocated bottom-up: method 2.
105: This uses the technique (and, loosely, the code)
106: described in the VCPI spec, version 1.0. */
107: if (ext_mem_top > ext_mem_bot)
108: {
109: struct {
110: char pad1[3];
111: char V;
112: long DISK;
113: char pad2[30-8];
114: unsigned short addr;
115: } buf;
116: unsigned char rc;
117:
118: i16_assert(sizeof(buf) == 0x20);
119: rc = i16_bios_copy_ext_mem(0x100000, kvtolin((vm_offset_t)&buf), sizeof(buf)/2);
120: if ((rc == 0) && (buf.V == 'V') && (buf.DISK == 'DISK'))
121: {
122: vm_offset_t new_bot = (vm_offset_t)buf.addr << 10;
123: i16_assert(new_bot > 0x100000);
124: if (new_bot > ext_mem_bot)
125: ext_mem_bot = new_bot;
126: }
127: }
128: i16_assert(ext_mem_bot >= 0x100000);
129:
130: if (ext_mem_top > ext_mem_bot)
131: {
132: ext_mem_phys_free_mem = ext_mem_bot;
133: ext_mem_phys_free_size = ext_mem_top - ext_mem_bot;
134:
135: /* We need to update phys_mem_max here
136: instead of just letting phys_mem_add() do it
137: when the memory is collected with phys_mem_collect(),
138: because VCPI initialization needs to know the top of physical memory
139: before phys_mem_collect() is called.
140: See i16_vcpi.c for the gross details. */
141: if (ext_mem_top > phys_mem_max)
142: phys_mem_max = ext_mem_top;
143: }
144: }
145:
146: void i16_ext_mem_shutdown()
147: {
148: /* We didn't actually allocate the memory,
149: so no need to deallocate it... */
150: }
151:
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