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2455 | mario79 | 1 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; |
2 | ;; ;; |
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4850 | mario79 | 3 | ;; Copyright (C) KolibriOS team 2004-2014. All rights reserved. ;; |
2455 | mario79 | 4 | ;; Distributed under terms of the GNU General Public License ;; |
5 | ;; ;; |
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6 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; |
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7 | |||
4850 | mario79 | 8 | $Revision: 4850 $ |
9 | |||
10 | |||
796 | shurf | 11 | ; FAT12 boot sector for Kolibri OS |
12 | ; |
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13 | ; Copyright (C) Alex Nogueira Teixeira |
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14 | ; Copyright (C) Diamond |
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15 | ; Copyright (C) Dmitry Kartashov aka shurf |
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16 | ; |
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17 | ; Distributed under GPL, see file COPYING for details |
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18 | ; |
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19 | ; Version 1.0 |
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20 | |||
3274 | esevece | 21 | include "lang.inc" |
22 | |||
2288 | clevermous | 23 | lf equ 0ah |
24 | cr equ 0dh |
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796 | shurf | 25 | |
2288 | clevermous | 26 | pos_read_tmp equ 0700h ;position for temporary read |
27 | boot_program equ 07c00h ;position for boot code |
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28 | seg_read_kernel equ 01000h ;segment to kernel read |
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796 | shurf | 29 | |
2288 | clevermous | 30 | jmp start_program |
31 | nop |
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796 | shurf | 32 | |
33 | ; Boot Sector and BPB Structure |
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34 | include 'floppy1440.inc' |
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35 | ;include 'floppy2880.inc' |
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36 | ;include 'floppy1680.inc' |
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37 | ;include 'floppy1743.inc' |
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38 | |||
39 | start_program: |
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40 | |||
2288 | clevermous | 41 | xor ax, ax |
42 | mov ss, ax |
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43 | mov sp, boot_program |
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44 | push ss |
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45 | pop ds |
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796 | shurf | 46 | |
2288 | clevermous | 47 | ; print loading string |
48 | mov si, loading+boot_program |
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796 | shurf | 49 | loop_loading: |
2288 | clevermous | 50 | lodsb |
51 | or al, al |
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52 | jz read_root_directory |
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53 | mov ah, 0eh |
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54 | mov bx, 7 |
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55 | int 10h |
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56 | jmp loop_loading |
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796 | shurf | 57 | |
58 | read_root_directory: |
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2288 | clevermous | 59 | push ss |
60 | pop es |
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796 | shurf | 61 | |
2288 | clevermous | 62 | ; calculate some disk parameters |
63 | ; - beginning sector of RootDir |
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64 | mov ax, word [BPB_FATSz16+boot_program] |
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65 | xor cx, cx |
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66 | mov cl, byte [BPB_NumFATs+boot_program] |
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67 | mul cx |
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68 | add ax, word [BPB_RsvdSecCnt+boot_program] |
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69 | mov word [FirstRootDirSecNum+boot_program], ax ; 19 |
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70 | mov si, ax |
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796 | shurf | 71 | |
2288 | clevermous | 72 | ; - count of sectors in RootDir |
73 | mov bx, word [BPB_BytsPerSec+boot_program] |
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74 | mov cl, 5 ; divide ax by 32 |
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75 | shr bx, cl ; bx = directory entries per sector |
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76 | mov ax, word [BPB_RootEntCnt+boot_program] |
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77 | xor dx, dx |
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78 | div bx |
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79 | mov word [RootDirSecs+boot_program], ax ; 14 |
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796 | shurf | 80 | |
2288 | clevermous | 81 | ; - data start |
82 | add si, ax ; add beginning sector of RootDir and count sectors in RootDir |
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83 | mov word [data_start+boot_program], si ; 33 |
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84 | ; reading root directory |
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85 | ; al=count root dir sectrors !!!! TODO: al, max 255 sectors !!!! |
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86 | mov ah, 2 ; read |
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87 | push ax |
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796 | shurf | 88 | |
2288 | clevermous | 89 | mov ax, word [FirstRootDirSecNum+boot_program] |
90 | call conv_abs_to_THS ; convert abs sector (AX) to BIOS T:H:S (track:head:sector) |
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91 | pop ax |
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92 | mov bx, pos_read_tmp ; es:bx read buffer |
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93 | call read_sector |
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796 | shurf | 94 | |
2288 | clevermous | 95 | mov si, bx ; read buffer address: es:si |
96 | mov ax, [RootDirSecs+boot_program] |
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97 | mul word [BPB_BytsPerSec+boot_program] |
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98 | add ax, si ; AX = end of root dir. in buffer pos_read_tmp |
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796 | shurf | 99 | |
2288 | clevermous | 100 | ; find kernel file in root directory |
796 | shurf | 101 | loop_find_dir_entry: |
2288 | clevermous | 102 | push si |
103 | mov cx, 11 |
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104 | mov di, kernel_name+boot_program |
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105 | rep cmpsb ; compare es:si and es:di, cx bytes long |
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106 | pop si |
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107 | je found_kernel_file |
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108 | add si, 32 ; next dir. entry |
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109 | cmp si, ax ; end of directory |
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110 | jb loop_find_dir_entry |
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796 | shurf | 111 | |
112 | file_error_message: |
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2288 | clevermous | 113 | mov si, error_message+boot_program |
796 | shurf | 114 | |
115 | loop_error_message: |
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2288 | clevermous | 116 | lodsb |
117 | or al, al |
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118 | jz freeze_pc |
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119 | mov ah, 0eh |
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120 | mov bx, 7 |
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121 | int 10h |
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122 | jmp loop_error_message |
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796 | shurf | 123 | |
124 | freeze_pc: |
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2288 | clevermous | 125 | jmp $ ; endless loop |
796 | shurf | 126 | |
2288 | clevermous | 127 | ; === KERNEL FOUND. LOADING... === |
796 | shurf | 128 | |
129 | found_kernel_file: |
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2288 | clevermous | 130 | mov bp, [si+01ah] ; first cluster of kernel file |
131 | ; |
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132 | mov [cluster1st+boot_program], bp ; starting cluster of kernel file |
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133 | ; <\diamond> |
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796 | shurf | 134 | |
2288 | clevermous | 135 | ; reading first FAT table |
136 | mov ax, word [BPB_RsvdSecCnt+boot_program] ; begin first FAT abs sector number |
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137 | call conv_abs_to_THS ; convert abs sector (AX) to BIOS T:H:S (track:head:sector) |
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138 | mov bx, pos_read_tmp ; es:bx read position |
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139 | mov ah, 2 ; ah=2 (read) |
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140 | mov al, byte [BPB_FATSz16+boot_program] ; FAT size in sectors (TODO: max 255 sectors) |
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141 | call read_sector |
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142 | jc file_error_message ; read error |
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796 | shurf | 143 | |
2288 | clevermous | 144 | mov ax, seg_read_kernel |
145 | mov es, ax |
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146 | xor bx, bx ; es:bx = 1000h:0000h |
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796 | shurf | 147 | |
148 | |||
2288 | clevermous | 149 | ; reading kernel file |
796 | shurf | 150 | loop_obtains_kernel_data: |
2288 | clevermous | 151 | ; read one cluster of file |
152 | call obtain_cluster |
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153 | jc file_error_message ; read error |
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796 | shurf | 154 | |
2288 | clevermous | 155 | ; add one cluster length to segment:offset |
156 | push bx |
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157 | mov bx, es |
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158 | mov ax, word [BPB_BytsPerSec+boot_program] ;\ |
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159 | movsx cx, byte [BPB_SecPerClus+boot_program] ; | !!! TODO: !!! |
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160 | mul cx ; | out this from loop !!! |
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161 | shr ax, 4 ;/ |
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162 | add bx, ax |
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163 | mov es, bx |
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164 | pop bx |
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796 | shurf | 165 | |
2288 | clevermous | 166 | mov di, bp |
167 | shr di, 1 |
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168 | pushf |
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169 | add di, bp ; di = bp * 1.5 |
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170 | add di, pos_read_tmp |
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171 | mov ax, [di] ; read next entry from FAT-chain |
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172 | popf |
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173 | jc move_4_right |
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174 | and ax, 0fffh |
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175 | jmp verify_end_sector |
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796 | shurf | 176 | move_4_right: |
2288 | clevermous | 177 | mov cl, 4 |
178 | shr ax, cl |
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796 | shurf | 179 | verify_end_sector: |
2288 | clevermous | 180 | cmp ax, 0ff8h ; last cluster |
181 | jae execute_kernel |
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182 | mov bp, ax |
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183 | jmp loop_obtains_kernel_data |
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796 | shurf | 184 | |
185 | execute_kernel: |
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2288 | clevermous | 186 | ; |
187 | mov ax, 'KL' |
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188 | push 0 |
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189 | pop ds |
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190 | mov si, loader_block+boot_program |
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191 | ; |
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192 | push word seg_read_kernel |
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193 | push word 0 |
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194 | retf ; jmp far 1000:0000 |
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796 | shurf | 195 | |
196 | |||
197 | ;------------------------------------------ |
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2288 | clevermous | 198 | ; loading cluster from file to es:bx |
796 | shurf | 199 | obtain_cluster: |
2288 | clevermous | 200 | ; bp - cluster number to read |
201 | ; carry = 0 -> read OK |
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202 | ; carry = 1 -> read ERROR |
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796 | shurf | 203 | |
2288 | clevermous | 204 | ; print one dot |
205 | push bx |
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206 | mov ax, 0e2eh ; ah=0eh (teletype), al='.' |
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207 | xor bh, bh |
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208 | int 10h |
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209 | pop bx |
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796 | shurf | 210 | |
1738 | clevermous | 211 | writesec: |
2288 | clevermous | 212 | ; convert cluster number to sector number |
213 | mov ax, bp ; data cluster to read |
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214 | sub ax, 2 |
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215 | xor dx, dx |
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216 | mov dl, byte [BPB_SecPerClus+boot_program] |
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217 | mul dx |
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218 | add ax, word [data_start+boot_program] |
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796 | shurf | 219 | |
2288 | clevermous | 220 | call conv_abs_to_THS ; convert abs sector (AX) to BIOS T:H:S (track:head:sector) |
796 | shurf | 221 | patchhere: |
2288 | clevermous | 222 | mov ah, 2 ; ah=2 (read) |
223 | mov al, byte [BPB_SecPerClus+boot_program] ; al=(one cluster) |
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224 | call read_sector |
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225 | retn |
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796 | shurf | 226 | ;------------------------------------------ |
227 | |||
228 | ;------------------------------------------ |
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2288 | clevermous | 229 | ; read sector from disk |
796 | shurf | 230 | read_sector: |
2288 | clevermous | 231 | push bp |
232 | mov bp, 20 ; try 20 times |
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796 | shurf | 233 | newread: |
2288 | clevermous | 234 | dec bp |
235 | jz file_error_message |
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236 | push ax bx cx dx |
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237 | int 13h |
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238 | pop dx cx bx ax |
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239 | jc newread |
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240 | pop bp |
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241 | retn |
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796 | shurf | 242 | ;------------------------------------------ |
2288 | clevermous | 243 | ; convert abs. sector number (AX) to BIOS T:H:S |
244 | ; sector number = (abs.sector%BPB_SecPerTrk)+1 |
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245 | ; pre.track number = (abs.sector/BPB_SecPerTrk) |
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246 | ; head number = pre.track number%BPB_NumHeads |
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247 | ; track number = pre.track number/BPB_NumHeads |
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248 | ; Return: cl - sector number |
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249 | ; ch - track number |
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250 | ; dl - drive number (0 = a:) |
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251 | ; dh - head number |
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796 | shurf | 252 | conv_abs_to_THS: |
2288 | clevermous | 253 | push bx |
254 | mov bx, word [BPB_SecPerTrk+boot_program] |
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255 | xor dx, dx |
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256 | div bx |
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257 | inc dx |
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258 | mov cl, dl ; cl = sector number |
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259 | mov bx, word [BPB_NumHeads+boot_program] |
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260 | xor dx, dx |
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261 | div bx |
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262 | ; !!!!!!! ax = track number, dx = head number |
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263 | mov ch, al ; ch=track number |
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264 | xchg dh, dl ; dh=head number |
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265 | mov dl, 0 ; dl=0 (drive 0 (a:)) |
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266 | pop bx |
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267 | retn |
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796 | shurf | 268 | ;------------------------------------------ |
269 | |||
3274 | esevece | 270 | if lang eq sp |
271 | loading db cr,lf,'Iniciando el sistema ',00h |
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272 | else |
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2288 | clevermous | 273 | loading db cr,lf,'Starting system ',00h |
3274 | esevece | 274 | end if |
2288 | clevermous | 275 | error_message db 13,10 |
276 | kernel_name db 'KERNEL MNT ?',cr,lf,00h |
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277 | FirstRootDirSecNum dw ? |
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278 | RootDirSecs dw ? |
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279 | data_start dw ? |
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796 | shurf | 280 | |
281 | ; |
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282 | write1st: |
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2288 | clevermous | 283 | push cs |
284 | pop ds |
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285 | mov byte [patchhere+1+boot_program], 3 ; change ah=2 to ah=3 |
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286 | mov bp, [cluster1st+boot_program] |
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287 | push 1000h |
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288 | pop es |
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289 | xor bx, bx |
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290 | call writesec |
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291 | mov byte [patchhere+1+boot_program], 2 ; change back ah=3 to ah=2 |
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292 | retf |
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293 | cluster1st dw ? |
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796 | shurf | 294 | loader_block: |
2288 | clevermous | 295 | db 1 |
296 | dw 0 |
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297 | dw write1st+boot_program |
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298 | dw 0 |
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796 | shurf | 299 | ; <\diamond> |
300 | |||
2288 | clevermous | 301 | times 0x1fe-$ db 00h |
796 | shurf | 302 | |
2288 | clevermous | 303 | db 55h,0aah ;boot signature\diamond>\diamond> |