biosmemx.S revision 1.12
1 1.12 andvar /* $NetBSD: biosmemx.S,v 1.12 2024/08/17 08:38:31 andvar Exp $ */ 2 1.1 drochner 3 1.1 drochner /* 4 1.2 drochner * Copyright (c) 1997, 1999 5 1.1 drochner * Matthias Drochner. All rights reserved. 6 1.1 drochner * 7 1.1 drochner * Redistribution and use in source and binary forms, with or without 8 1.1 drochner * modification, are permitted provided that the following conditions 9 1.1 drochner * are met: 10 1.1 drochner * 1. Redistributions of source code must retain the above copyright 11 1.1 drochner * notice, this list of conditions and the following disclaimer. 12 1.1 drochner * 2. Redistributions in binary form must reproduce the above copyright 13 1.1 drochner * notice, this list of conditions and the following disclaimer in the 14 1.1 drochner * documentation and/or other materials provided with the distribution. 15 1.1 drochner * 16 1.1 drochner * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 1.1 drochner * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 1.1 drochner * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 1.1 drochner * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 1.1 drochner * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 1.1 drochner * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 1.1 drochner * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 1.1 drochner * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 1.1 drochner * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 1.1 drochner * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 1.1 drochner * 27 1.1 drochner */ 28 1.1 drochner 29 1.1 drochner #include <machine/asm.h> 30 1.1 drochner 31 1.1 drochner .text 32 1.1 drochner 33 1.10 maxv /* 34 1.10 maxv * int getextmem2(int buffer[2]) 35 1.10 maxv * 36 1.10 maxv * return: 0=OK, -1=error 37 1.10 maxv * buffer[0]: extmem kBytes below 16M (max 15M/1024) 38 1.10 maxv * buffer[1]: extmem above 16M, in 64k units 39 1.10 maxv */ 40 1.1 drochner ENTRY(getextmem2) 41 1.1 drochner pushl %ebp 42 1.1 drochner movl %esp,%ebp 43 1.1 drochner pushl %ebx 44 1.1 drochner pushl %ecx 45 1.1 drochner pushl %edx 46 1.1 drochner push %esi 47 1.1 drochner push %edi 48 1.1 drochner 49 1.1 drochner call _C_LABEL(prot_to_real) 50 1.3 dsl .code16 51 1.1 drochner 52 1.10 maxv xorl %ebx,%ebx 53 1.10 maxv movl $0xe801,%eax 54 1.1 drochner int $0x15 55 1.6 dsl pushf 56 1.1 drochner 57 1.10 maxv movw %si,%ax 58 1.10 maxv orw %si,%bx 59 1.6 dsl jz 1f /* if zero use configured values */ 60 1.10 maxv movw %cx,%ax /* k below 16M (max 0x3c00 = 15MB) */ 61 1.10 maxv movw %dx,%bx /* 64k above 16M */ 62 1.6 dsl 1: 63 1.6 dsl popf 64 1.6 dsl setc %bl 65 1.1 drochner 66 1.3 dsl calll _C_LABEL(real_to_prot) 67 1.3 dsl .code32 68 1.1 drochner 69 1.10 maxv movl 8(%ebp),%edi 70 1.10 maxv xorl %eax,%eax 71 1.10 maxv movw %cx,%ax 72 1.6 dsl stosl 73 1.10 maxv movw %dx,%ax 74 1.6 dsl stosl 75 1.10 maxv movb %bl,%al 76 1.6 dsl cbw 77 1.1 drochner 78 1.1 drochner pop %edi 79 1.1 drochner pop %esi 80 1.1 drochner popl %edx 81 1.1 drochner popl %ecx 82 1.1 drochner popl %ebx 83 1.1 drochner popl %ebp 84 1.1 drochner ret 85 1.1 drochner 86 1.10 maxv /* 87 1.12 andvar * int getmementry(int *iterator, int buffer[6]) 88 1.10 maxv * 89 1.10 maxv * return: 0=ok, else error 90 1.10 maxv * buffer[0]: start of memory chunk 91 1.10 maxv * buffer[2]: length (bytes) 92 1.10 maxv * buffer[4]: type 93 1.12 andvar * buffer[5]: ACPI 3.0 Extended Attributes bitfield (unused) 94 1.12 andvar * Some buggy BIOSes may write to 24 bytes even if only 20 were requested. 95 1.12 andvar * Therefore, the buffer is defined for 6 elements to avoid stack buffer 96 1.12 andvar * overruns. See PR install/49470. 97 1.12 andvar * 98 1.12 andvar * More details can be found in the 99 1.12 andvar * Advanced Configuration and Power Interface (ACPI) Specification, Release 6.5, 100 1.12 andvar * 2022-08-29, UEFI Forum, Inc., 101 1.12 andvar * Sec. 15.1 `INT 15H E820H - Query System Address Map', pp. 756-757 102 1.12 andvar * https://uefi.org/sites/default/files/resources/ACPI_Spec_6_5_Aug29.pdf#page=824 103 1.12 andvar * https://uefi.org/specs/ACPI/6.5/15_System_Address_Map_Interfaces.html#int-15h-e820h-query-system-address-map 104 1.12 andvar * as well as OSDev.org wiki page 105 1.12 andvar * https://wiki.osdev.org/Detecting_Memory_(x86)#BIOS_Function:_INT_0x15,_EAX_=_0xE820. 106 1.10 maxv */ 107 1.1 drochner ENTRY(getmementry) 108 1.1 drochner pushl %ebp 109 1.1 drochner movl %esp,%ebp 110 1.1 drochner pushl %ebx 111 1.1 drochner pushl %ecx 112 1.1 drochner pushl %edx 113 1.1 drochner push %esi 114 1.1 drochner push %edi 115 1.1 drochner 116 1.10 maxv movl 8(%ebp),%eax 117 1.10 maxv movl 0(%eax),%ebx /* index */ 118 1.10 maxv movl $20,%ecx /* Buffer size */ 119 1.10 maxv movl $0x534d4150,%edx /* "SMAP" */ 120 1.10 maxv movl 12(%ebp),%edi /* buffer address */ 121 1.1 drochner 122 1.1 drochner call _C_LABEL(prot_to_real) 123 1.3 dsl .code16 124 1.4 dsl 125 1.4 dsl push %di 126 1.10 maxv shrl $4,%edi 127 1.10 maxv mov %ds,%ax 128 1.10 maxv add %di,%ax 129 1.10 maxv mov %ax,%es 130 1.4 dsl pop %di 131 1.11 andvar and $0xf,%di /* buffer address now in ES:DI */ 132 1.1 drochner 133 1.10 maxv movl $0xe820,%eax /* Some BIOS check EAX value */ 134 1.1 drochner int $0x15 135 1.1 drochner 136 1.2 drochner setc %cl 137 1.1 drochner 138 1.3 dsl calll _C_LABEL(real_to_prot) 139 1.3 dsl .code32 140 1.1 drochner 141 1.10 maxv movl 8(%ebp),%eax 142 1.10 maxv movl %ebx,0(%eax) /* updated index */ 143 1.10 maxv xorl %eax,%eax 144 1.10 maxv movb %cl,%al 145 1.1 drochner 146 1.1 drochner pop %edi 147 1.1 drochner pop %esi 148 1.1 drochner popl %edx 149 1.1 drochner popl %ecx 150 1.1 drochner popl %ebx 151 1.1 drochner popl %ebp 152 1.1 drochner ret 153 1.9 ad 154 1.10 maxv /* 155 1.10 maxv * int biosA20(void) 156 1.10 maxv * 157 1.10 maxv * return: 0=ok, else error 158 1.10 maxv */ 159 1.9 ad ENTRY(biosA20) 160 1.9 ad pushl %ebp 161 1.9 ad movl %esp,%ebp 162 1.9 ad pushl %ebx 163 1.9 ad pushl %ecx 164 1.9 ad pushl %edx 165 1.9 ad push %esi 166 1.9 ad push %edi 167 1.9 ad 168 1.9 ad call _C_LABEL(prot_to_real) 169 1.9 ad .code16 170 1.9 ad 171 1.10 maxv movl $0x2401,%eax 172 1.9 ad int $0x15 173 1.9 ad setc %cl 174 1.9 ad 175 1.9 ad calll _C_LABEL(real_to_prot) 176 1.9 ad .code32 177 1.9 ad 178 1.10 maxv movzbl %cl,%eax 179 1.9 ad 180 1.9 ad pop %edi 181 1.9 ad pop %esi 182 1.9 ad popl %edx 183 1.9 ad popl %ecx 184 1.9 ad popl %ebx 185 1.9 ad popl %ebp 186 1.9 ad ret 187
Indexes created Tue Sep 30 17:09:57 GMT 2025