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         .text
  21         .code16
  22
  23 #define ASM
  24
  25 #include <arch.h>
  26
  27
  28 /*
  29  * U32 PnpBiosSupported(VOID);
  30  *
  31  * RETURNS:
  32  */
  33 _pnp_bios_entry_point:
  34         .long   0
  35 _pnp_bios_data_segment:
  36         .word   0
  37
  38 EXTERN(PnpBiosSupported)
  39         .code64
  40
  41         push rdi
  42         push rsi
  43         push rcx
  44         push rdx
  45
  46         xor edi, edi
  47
  48         /* init esi */
  49         mov esi, 0xF0000
  50
  51 pnp_again:
  52         mov eax, [%esi]
  53         cmp eax, 0x506E5024                     /* "$PnP" */
  54         je pnp_found
  55
  56         cmp esi, 0xFFFF0
  57         je pnp_not_found
  58
  59 pnp_add:
  60         add esi, 0x10
  61         jmp pnp_again
  62
  63 pnp_found:
  64         /* first calculate the checksum */
  65         push rsi
  66
  67         push 0x21
  68         pop rcx
  69         xor edx, edx
  70
  71 pnp_loop:
  72         lodsb
  73         add dl, al
  74         loop pnp_loop
  75
  76         test dl, dl
  77         pop rsi
  78         jnz pnp_add
  79
  80         mov edi, esi
  81
  82         /* Calculate the bios entry point (far pointer) */
  83         xor eax, eax
  84         mov ax, [esi + 0x0F]
  85         shl eax, 16
  86         mov ax, [esi + 0x0D]
  87         mov _pnp_bios_entry_point, eax
  88
  89         /* Store bios data segment */
  90         mov ax, [esi + 0x1B]
  91         mov _pnp_bios_data_segment, ax
  92
  93 pnp_not_found:
  94         mov eax, edi
  95
  96         pop rdx
  97         pop rcx
  98         pop rsi
  99         pop rdi
 100
 101         ret
 102
 103
 104 /*
 105  * U32 PnpBiosGetDeviceNodeCount(U32 *NodeSize, U32 *NodeCount);
 106  *
 107  * RETURNS:
 108  */
 109 _pnp_result:
 110         .long   0
 111 _pnp_node_size:
 112         .word   0
 113 _pnp_node_count:
 114         .word   0
 115
 116 EXTERN(PnpBiosGetDeviceNodeCount)
 117         .code64
 118
 119         push rbp
 120         mov rbp, rsp
 121
 122 //      pushal FIXME
 123 //      push es
 124
 125         call x86_64_SwitchToReal
 126         .code16
 127
 128         mov ax, _pnp_bios_data_segment
 129         push ax
 130
 131         push cs
 132         mov ax, _pnp_node_size
 133         push ax
 134
 135         push cs
 136         mov ax, _pnp_node_count
 137         push ax
 138
 139         push 0
 140
 141         call [_pnp_bios_entry_point]
 142         add sp, 12
 143
 144         movzx ecx, ax
 145         mov _pnp_result, ecx
 146
 147         call    x86_16_SwitchToLong
 148         .code64
 149
 150         mov esi, [rbp + 0x08]
 151         mov ax, _pnp_node_size
 152         movzx ecx, ax
 153         mov [rsi], ecx
 154
 155         mov rsi, [ebp + 0x0C]
 156         mov ax, _pnp_node_count
 157         movzx ecx, ax
 158         mov [rsi], eax
 159
 160 //      pop es
 161 //      popal
 162
 163         mov rsp, rbp
 164         pop rbp
 165
 166         xor rax, rax
 167         mov eax, _pnp_result
 168
 169         ret
 170
 171
 172 /*
 173  * U32 PnpBiosGetDeviceNode(U8 *NodeId, U8 *NodeBuffer);
 174  *
 175  * RETURNS:
 176  */
 177 _pnp_buffer_segment:
 178         .word   0
 179 _pnp_buffer_offset:
 180         .word   0
 181
 182 _pnp_node_number:
 183         .byte   0
 184
 185 EXTERN(PnpBiosGetDeviceNode)
 186         .code64
 187
 188         push rbp
 189         mov rbp, rsp
 190
 191 //      pushal
 192 //      push es
 193
 194         /* get current node number */
 195         mov rsi, [rbp + 0x08]
 196         mov al, [rsi]
 197         mov _pnp_node_number, al
 198
 199         /* convert pointer to node buffer to segment/offset */
 200         mov eax, [rbp + 0x0C]
 201         shr eax, 4
 202         and eax, 0xf000
 203         mov _pnp_buffer_segment , ax
 204         mov eax, [rbp + 0x0C]
 205         and eax, 0xffff
 206         mov _pnp_buffer_offset, ax
 207
 208         call x86_64_SwitchToReal
 209         .code16
 210
 211         /* push bios segment */
 212         mov ax, _pnp_bios_data_segment
 213         push ax
 214
 215         /* push control flag */
 216         push 0x0001
 217
 218         /* push pointer to node buffer (segment/offset) */
 219         mov ax, _pnp_buffer_segment
 220         push ax
 221         mov ax, _pnp_buffer_offset
 222         push ax
 223
 224         /* push pointer to node number (segment/offset) */
 225         push cs
 226         mov ax, _pnp_node_number
 227         push ax
 228
 229         /* push function number */
 230         push 1
 231
 232         /* call entry point */
 233         call [_pnp_bios_entry_point]
 234         add sp, 14
 235
 236         movzx ecx, ax
 237         mov _pnp_result, ecx
 238
 239         call x86_16_SwitchToLong
 240         .code64
 241
 242         /* update node number */
 243         mov rsi, [rbp + 0x08]
 244         mov al, _pnp_node_number
 245         mov [rsi], al
 246
 247 //      pop es
 248 //      popal
 249
 250         mov rsp, rbp
 251         pop rbp
 252
 253         xor rax, rax
 254         mov eax, _pnp_result
 255
 256         ret
 257
 258 /* EOF */