reactos/boot/freeldr/freeldr/arch/amd64/i386pnp.S

   1 /*
   2  *  FreeLoader
   3  *  Copyright (C) 2003  Eric Kohl
   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; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License along
  16  *  with this program; if not, write to the Free Software Foundation, Inc.,
  17  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #include <asm.inc>
  21
  22
  23         .text
  24         .code16
  25
  26 #define ASM
  27
  28 #include <arch.h>
  29
  30
  31 /*
  32  * U32 PnpBiosSupported(VOID);
  33  *
  34  * RETURNS:
  35  */
  36 _pnp_bios_entry_point:
  37         .long   0
  38 _pnp_bios_data_segment:
  39         .word   0
  40
  41 EXTERN(PnpBiosSupported)
  42         .code64
  43
  44         push rdi
  45         push rsi
  46         push rcx
  47         push rdx
  48
  49         xor edi, edi
  50
  51         /* init esi */
  52         mov esi, 0xF0000
  53
  54 pnp_again:
  55         mov eax, [%esi]
  56         cmp eax, 0x506E5024                     /* "$PnP" */
  57         je pnp_found
  58
  59         cmp esi, 0xFFFF0
  60         je pnp_not_found
  61
  62 pnp_add:
  63         add esi, 0x10
  64         jmp pnp_again
  65
  66 pnp_found:
  67         /* first calculate the checksum */
  68         push rsi
  69
  70         push 0x21
  71         pop rcx
  72         xor edx, edx
  73
  74 pnp_loop:
  75         lodsb
  76         add dl, al
  77         loop pnp_loop
  78
  79         test dl, dl
  80         pop rsi
  81         jnz pnp_add
  82
  83         mov edi, esi
  84
  85         /* Calculate the bios entry point (far pointer) */
  86         xor eax, eax
  87         mov ax, [esi + 0x0F]
  88         shl eax, 16
  89         mov ax, [esi + 0x0D]
  90         mov _pnp_bios_entry_point, eax
  91
  92         /* Store bios data segment */
  93         mov ax, [esi + 0x1B]
  94         mov _pnp_bios_data_segment, ax
  95
  96 pnp_not_found:
  97         mov eax, edi
  98
  99         pop rdx
 100         pop rcx
 101         pop rsi
 102         pop rdi
 103
 104         ret
 105
 106
 107 /*
 108  * U32 PnpBiosGetDeviceNodeCount(U32 *NodeSize, U32 *NodeCount);
 109  *
 110  * RETURNS:
 111  */
 112 _pnp_result:
 113         .long   0
 114 _pnp_node_size:
 115         .word   0
 116 _pnp_node_count:
 117         .word   0
 118
 119 EXTERN(PnpBiosGetDeviceNodeCount)
 120         .code64
 121
 122         push rbp
 123         mov rbp, rsp
 124
 125 //      pushal FIXME
 126 //      push es
 127
 128         call x86_64_SwitchToReal
 129         .code16
 130
 131         mov ax, _pnp_bios_data_segment
 132         push ax
 133
 134         push cs
 135         mov ax, _pnp_node_size
 136         push ax
 137
 138         push cs
 139         mov ax, _pnp_node_count
 140         push ax
 141
 142         push 0
 143
 144         call [_pnp_bios_entry_point]
 145         add sp, 12
 146
 147         movzx ecx, ax
 148         mov _pnp_result, ecx
 149
 150         call    x86_16_SwitchToLong
 151         .code64
 152
 153         mov esi, [rbp + 0x08]
 154         mov ax, _pnp_node_size
 155         movzx ecx, ax
 156         mov [rsi], ecx
 157
 158         mov rsi, [ebp + 0x0C]
 159         mov ax, _pnp_node_count
 160         movzx ecx, ax
 161         mov [rsi], eax
 162
 163 //      pop es
 164 //      popal
 165
 166         mov rsp, rbp
 167         pop rbp
 168
 169         xor rax, rax
 170         mov eax, _pnp_result
 171
 172         ret
 173
 174
 175 /*
 176  * U32 PnpBiosGetDeviceNode(U8 *NodeId, U8 *NodeBuffer);
 177  *
 178  * RETURNS:
 179  */
 180 _pnp_buffer_segment:
 181         .word   0
 182 _pnp_buffer_offset:
 183         .word   0
 184
 185 _pnp_node_number:
 186         .byte   0
 187
 188 EXTERN(PnpBiosGetDeviceNode)
 189         .code64
 190
 191         push rbp
 192         mov rbp, rsp
 193
 194 //      pushal
 195 //      push es
 196
 197         /* get current node number */
 198         mov rsi, [rbp + 0x08]
 199         mov al, [rsi]
 200         mov _pnp_node_number, al
 201
 202         /* convert pointer to node buffer to segment/offset */
 203         mov eax, [rbp + 0x0C]
 204         shr eax, 4
 205         and eax, 0xf000
 206         mov _pnp_buffer_segment , ax
 207         mov eax, [rbp + 0x0C]
 208         and eax, 0xffff
 209         mov _pnp_buffer_offset, ax
 210
 211         call x86_64_SwitchToReal
 212         .code16
 213
 214         /* push bios segment */
 215         mov ax, _pnp_bios_data_segment
 216         push ax
 217
 218         /* push control flag */
 219         push 0x0001
 220
 221         /* push pointer to node buffer (segment/offset) */
 222         mov ax, _pnp_buffer_segment
 223         push ax
 224         mov ax, _pnp_buffer_offset
 225         push ax
 226
 227         /* push pointer to node number (segment/offset) */
 228         push cs
 229         mov ax, _pnp_node_number
 230         push ax
 231
 232         /* push function number */
 233         push 1
 234
 235         /* call entry point */
 236         call [_pnp_bios_entry_point]
 237         add sp, 14
 238
 239         movzx ecx, ax
 240         mov _pnp_result, ecx
 241
 242         call x86_16_SwitchToLong
 243         .code64
 244
 245         /* update node number */
 246         mov rsi, [rbp + 0x08]
 247         mov al, _pnp_node_number
 248         mov [rsi], al
 249
 250 //      pop es
 251 //      popal
 252
 253         mov rsp, rbp
 254         pop rbp
 255
 256         xor rax, rax
 257         mov eax, _pnp_result
 258
 259         ret
 260
 261 END
 262 /* EOF */