| btxldr.S (128716) | btxldr.S (129240) |
|---|---|
| 1/* 2 * Copyright (c) 1998 Robert Nordier 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are freely 6 * permitted provided that the above copyright notice and this 7 * paragraph and the following disclaimer are duplicated in all 8 * such forms. 9 * 10 * This software is provided "AS IS" and without any express or 11 * implied warranties, including, without limitation, the implied 12 * warranties of merchantability and fitness for a particular 13 * purpose. 14 * | 1/* 2 * Copyright (c) 1998 Robert Nordier 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are freely 6 * permitted provided that the above copyright notice and this 7 * paragraph and the following disclaimer are duplicated in all 8 * such forms. 9 * 10 * This software is provided "AS IS" and without any express or 11 * implied warranties, including, without limitation, the implied 12 * warranties of merchantability and fitness for a particular 13 * purpose. 14 * |
| 15 * $FreeBSD: head/sys/boot/i386/btx/btxldr/btxldr.S 128716 2004-04-28 14:31:44Z ru $ | 15 * $FreeBSD: head/sys/boot/i386/btx/btxldr/btxldr.S 129240 2004-05-14 20:29:30Z ru $ |
| 16 */ 17 18/* 19 * Prototype BTX loader program, written in a couple of hours. The 20 * real thing should probably be more flexible, and in C. 21 */ 22 23/* 24 * Memory locations. 25 */ | 16 */ 17 18/* 19 * Prototype BTX loader program, written in a couple of hours. The 20 * real thing should probably be more flexible, and in C. 21 */ 22 23/* 24 * Memory locations. 25 */ |
| 26 .set MEM_STUB,0x600 // Real mode stub 27 .set MEM_ESP,0x1000 // New stack pointer 28 .set MEM_TBL,0x5000 // BTX page tables 29 .set MEM_ENTRY,0x9010 // BTX entry point 30 .set MEM_DATA,start+0x1000 // Data segment | 26 .set MEM_STUB,0x600 # Real mode stub 27 .set MEM_ESP,0x1000 # New stack pointer 28 .set MEM_TBL,0x5000 # BTX page tables 29 .set MEM_ENTRY,0x9010 # BTX entry point 30 .set MEM_DATA,start+0x1000 # Data segment |
| 31/* 32 * Segment selectors. 33 */ | 31/* 32 * Segment selectors. 33 */ |
| 34 .set SEL_SCODE,0x8 // 4GB code 35 .set SEL_SDATA,0x10 // 4GB data 36 .set SEL_RCODE,0x18 // 64K code 37 .set SEL_RDATA,0x20 // 64K data | 34 .set SEL_SCODE,0x8 # 4GB code 35 .set SEL_SDATA,0x10 # 4GB data 36 .set SEL_RCODE,0x18 # 64K code 37 .set SEL_RDATA,0x20 # 64K data |
| 38/* 39 * Paging constants. 40 */ | 38/* 39 * Paging constants. 40 */ |
| 41 .set PAG_SIZ,0x1000 // Page size 42 .set PAG_ENT,0x4 // Page entry size | 41 .set PAG_SIZ,0x1000 # Page size 42 .set PAG_ENT,0x4 # Page entry size |
| 43/* 44 * Screen constants. 45 */ | 43/* 44 * Screen constants. 45 */ |
| 46 .set SCR_MAT,0x7 // Mode/attribute 47 .set SCR_COL,0x50 // Columns per row 48 .set SCR_ROW,0x19 // Rows per screen | 46 .set SCR_MAT,0x7 # Mode/attribute 47 .set SCR_COL,0x50 # Columns per row 48 .set SCR_ROW,0x19 # Rows per screen |
| 49/* 50 * BIOS Data Area locations. 51 */ | 49/* 50 * BIOS Data Area locations. 51 */ |
| 52 .set BDA_MEM,0x413 // Free memory 53 .set BDA_SCR,0x449 // Video mode 54 .set BDA_POS,0x450 // Cursor position | 52 .set BDA_MEM,0x413 # Free memory 53 .set BDA_SCR,0x449 # Video mode 54 .set BDA_POS,0x450 # Cursor position |
| 55/* 56 * Required by aout gas inadequacy. 57 */ | 55/* 56 * Required by aout gas inadequacy. 57 */ |
| 58 .set SIZ_STUB,0x1a // Size of stub | 58 .set SIZ_STUB,0x1a # Size of stub |
| 59/* 60 * We expect to be loaded by boot2 at the origin defined in ./Makefile. 61 */ 62 .globl start 63/* 64 * BTX program loader for ELF clients. 65 */ | 59/* 60 * We expect to be loaded by boot2 at the origin defined in ./Makefile. 61 */ 62 .globl start 63/* 64 * BTX program loader for ELF clients. 65 */ |
| 66start: cld // String ops inc 67 movl $m_logo,%esi // Identify 68 call putstr // ourselves 69 movzwl BDA_MEM,%eax // Get base memory 70 shll $0xa,%eax // in bytes 71 movl %eax,%ebp // Base of user stack | 66start: cld # String ops inc 67 movl $m_logo,%esi # Identify 68 call putstr # ourselves 69 movzwl BDA_MEM,%eax # Get base memory 70 shll $0xa,%eax # in bytes 71 movl %eax,%ebp # Base of user stack |
| 72#ifdef BTXLDR_VERBOSE | 72#ifdef BTXLDR_VERBOSE |
| 73 movl $m_mem,%esi // Display 74 call hexout // amount of 75 call putstr // base memory | 73 movl $m_mem,%esi # Display 74 call hexout # amount of 75 call putstr # base memory |
| 76#endif | 76#endif |
| 77 lgdt gdtdesc // Load new GDT | 77 lgdt gdtdesc # Load new GDT |
| 78/* 79 * Relocate caller's arguments. 80 */ 81#ifdef BTXLDR_VERBOSE | 78/* 79 * Relocate caller's arguments. 80 */ 81#ifdef BTXLDR_VERBOSE |
| 82 movl $m_esp,%esi // Display 83 movl %esp,%eax // caller 84 call hexout // stack 85 call putstr // pointer 86 movl $m_args,%esi // Format string 87 leal 0x4(%esp,1),%ebx // First argument 88 movl $0x6,%ecx // Count 89start.1: movl (%ebx),%eax // Get argument and 90 addl $0x4,%ebx // bump pointer 91 call hexout // Display it 92 loop start.1 // Till done 93 call putstr // End message | 82 movl $m_esp,%esi # Display 83 movl %esp,%eax # caller 84 call hexout # stack 85 call putstr # pointer 86 movl $m_args,%esi # Format string 87 leal 0x4(%esp,1),%ebx # First argument 88 movl $0x6,%ecx # Count 89start.1: movl (%ebx),%eax # Get argument and 90 addl $0x4,%ebx # bump pointer 91 call hexout # Display it 92 loop start.1 # Till done 93 call putstr # End message |
| 94#endif | 94#endif |
| 95 movl $0x48,%ecx // Allocate space 96 subl %ecx,%ebp // for bootinfo 97 movl 0x18(%esp,1),%esi // Source: bootinfo 98 cmpl $0x0, %esi // If the bootinfo pointer 99 je start_null_bi // is null, don't copy it 100 movl %ebp,%edi // Destination 101 rep // Copy 102 movsb // it 103 movl %ebp,0x18(%esp,1) // Update pointer | 95 movl $0x48,%ecx # Allocate space 96 subl %ecx,%ebp # for bootinfo 97 movl 0x18(%esp,1),%esi # Source: bootinfo 98 cmpl $0x0, %esi # If the bootinfo pointer 99 je start_null_bi # is null, don't copy it 100 movl %ebp,%edi # Destination 101 rep # Copy 102 movsb # it 103 movl %ebp,0x18(%esp,1) # Update pointer |
| 104#ifdef BTXLDR_VERBOSE | 104#ifdef BTXLDR_VERBOSE |
| 105 movl $m_rel_bi,%esi // Display 106 movl %ebp,%eax // bootinfo 107 call hexout // relocation 108 call putstr // message | 105 movl $m_rel_bi,%esi # Display 106 movl %ebp,%eax # bootinfo 107 call hexout # relocation 108 call putstr # message |
| 109#endif | 109#endif |
| 110start_null_bi: movl $0x18,%ecx // Allocate space 111 subl %ecx,%ebp // for arguments 112 leal 0x4(%esp,1),%esi // Source 113 movl %ebp,%edi // Destination 114 rep // Copy 115 movsb // them | 110start_null_bi: movl $0x18,%ecx # Allocate space 111 subl %ecx,%ebp # for arguments 112 leal 0x4(%esp,1),%esi # Source 113 movl %ebp,%edi # Destination 114 rep # Copy 115 movsb # them |
| 116#ifdef BTXLDR_VERBOSE | 116#ifdef BTXLDR_VERBOSE |
| 117 movl $m_rel_args,%esi // Display 118 movl %ebp,%eax // argument 119 call hexout // relocation 120 call putstr // message | 117 movl $m_rel_args,%esi # Display 118 movl %ebp,%eax # argument 119 call hexout # relocation 120 call putstr # message |
| 121#endif 122/* 123 * Set up BTX kernel. 124 */ | 121#endif 122/* 123 * Set up BTX kernel. 124 */ |
| 125 movl $MEM_ESP,%esp // Set up new stack 126 movl $MEM_DATA,%ebx // Data segment 127 movl $m_vers,%esi // Display BTX 128 call putstr // version message 129 movb 0x5(%ebx),%al // Get major version 130 addb $'0',%al // Display 131 call putchr // it 132 movb $'.',%al // And a 133 call putchr // dot 134 movb 0x6(%ebx),%al // Get minor 135 xorb %ah,%ah // version 136 movb $0xa,%dl // Divide 137 divb %dl,%al // by 10 138 addb $'0',%al // Display 139 call putchr // tens 140 movb %ah,%al // Get units 141 addb $'0',%al // Display 142 call putchr // units 143 call putstr // End message 144 movl %ebx,%esi // BTX image 145 movzwl 0x8(%ebx),%edi // Compute 146 orl $PAG_SIZ/PAG_ENT-1,%edi // the 147 incl %edi // BTX 148 shll $0x2,%edi // load 149 addl $MEM_TBL,%edi // address 150 pushl %edi // Save load address 151 movzwl 0xa(%ebx),%ecx // Image size | 125 movl $MEM_ESP,%esp # Set up new stack 126 movl $MEM_DATA,%ebx # Data segment 127 movl $m_vers,%esi # Display BTX 128 call putstr # version message 129 movb 0x5(%ebx),%al # Get major version 130 addb $'0',%al # Display 131 call putchr # it 132 movb $'.',%al # And a 133 call putchr # dot 134 movb 0x6(%ebx),%al # Get minor 135 xorb %ah,%ah # version 136 movb $0xa,%dl # Divide 137 divb %dl,%al # by 10 138 addb $'0',%al # Display 139 call putchr # tens 140 movb %ah,%al # Get units 141 addb $'0',%al # Display 142 call putchr # units 143 call putstr # End message 144 movl %ebx,%esi # BTX image 145 movzwl 0x8(%ebx),%edi # Compute 146 orl $PAG_SIZ/PAG_ENT-1,%edi # the 147 incl %edi # BTX 148 shll $0x2,%edi # load 149 addl $MEM_TBL,%edi # address 150 pushl %edi # Save load address 151 movzwl 0xa(%ebx),%ecx # Image size |
| 152#ifdef BTXLDR_VERBOSE | 152#ifdef BTXLDR_VERBOSE |
| 153 pushl %ecx // Save image size | 153 pushl %ecx # Save image size |
| 154#endif | 154#endif |
| 155 rep // Relocate 156 movsb // BTX 157 movl %esi,%ebx // Keep place | 155 rep # Relocate 156 movsb # BTX 157 movl %esi,%ebx # Keep place |
| 158#ifdef BTXLDR_VERBOSE | 158#ifdef BTXLDR_VERBOSE |
| 159 movl $m_rel_btx,%esi // Restore 160 popl %eax // parameters 161 call hexout // and | 159 movl $m_rel_btx,%esi # Restore 160 popl %eax # parameters 161 call hexout # and |
| 162#endif | 162#endif |
| 163 popl %ebp // display | 163 popl %ebp # display |
| 164#ifdef BTXLDR_VERBOSE | 164#ifdef BTXLDR_VERBOSE |
| 165 movl %ebp,%eax // the 166 call hexout // relocation 167 call putstr // message | 165 movl %ebp,%eax # the 166 call hexout # relocation 167 call putstr # message |
| 168#endif | 168#endif |
| 169 addl $PAG_SIZ,%ebp // Display | 169 addl $PAG_SIZ,%ebp # Display |
| 170#ifdef BTXLDR_VERBOSE | 170#ifdef BTXLDR_VERBOSE |
| 171 movl $m_base,%esi // the 172 movl %ebp,%eax // user 173 call hexout // base 174 call putstr // address | 171 movl $m_base,%esi # the 172 movl %ebp,%eax # user 173 call hexout # base 174 call putstr # address |
| 175#endif 176/* 177 * Set up ELF-format client program. 178 */ | 175#endif 176/* 177 * Set up ELF-format client program. 178 */ |
| 179 cmpl $0x464c457f,(%ebx) // ELF magic number? 180 je start.3 // Yes 181 movl $e_fmt,%esi // Display error 182 call putstr // message 183start.2: jmp start.2 // Hang | 179 cmpl $0x464c457f,(%ebx) # ELF magic number? 180 je start.3 # Yes 181 movl $e_fmt,%esi # Display error 182 call putstr # message 183start.2: jmp start.2 # Hang |
| 184start.3: 185#ifdef BTXLDR_VERBOSE | 184start.3: 185#ifdef BTXLDR_VERBOSE |
| 186 movl $m_elf,%esi // Display ELF 187 call putstr // message 188 movl $m_segs,%esi // Format string | 186 movl $m_elf,%esi # Display ELF 187 call putstr # message 188 movl $m_segs,%esi # Format string |
| 189#endif | 189#endif |
| 190 movl $0x2,%edi // Segment count 191 movl 0x1c(%ebx),%edx // Get e_phoff 192 addl %ebx,%edx // To pointer 193 movzwl 0x2c(%ebx),%ecx // Get e_phnum 194start.4: cmpl $0x1,(%edx) // Is p_type PT_LOAD? 195 jne start.6 // No | 190 movl $0x2,%edi # Segment count 191 movl 0x1c(%ebx),%edx # Get e_phoff 192 addl %ebx,%edx # To pointer 193 movzwl 0x2c(%ebx),%ecx # Get e_phnum 194start.4: cmpl $0x1,(%edx) # Is p_type PT_LOAD? 195 jne start.6 # No |
| 196#ifdef BTXLDR_VERBOSE | 196#ifdef BTXLDR_VERBOSE |
| 197 movl 0x4(%edx),%eax // Display 198 call hexout // p_offset 199 movl 0x8(%edx),%eax // Display 200 call hexout // p_vaddr 201 movl 0x10(%edx),%eax // Display 202 call hexout // p_filesz 203 movl 0x14(%edx),%eax // Display 204 call hexout // p_memsz 205 call putstr // End message | 197 movl 0x4(%edx),%eax # Display 198 call hexout # p_offset 199 movl 0x8(%edx),%eax # Display 200 call hexout # p_vaddr 201 movl 0x10(%edx),%eax # Display 202 call hexout # p_filesz 203 movl 0x14(%edx),%eax # Display 204 call hexout # p_memsz 205 call putstr # End message |
| 206#endif | 206#endif |
| 207 pushl %esi // Save 208 pushl %edi // working 209 pushl %ecx // registers 210 movl 0x4(%edx),%esi // Get p_offset 211 addl %ebx,%esi // as pointer 212 movl 0x8(%edx),%edi // Get p_vaddr 213 addl %ebp,%edi // as pointer 214 movl 0x10(%edx),%ecx // Get p_filesz 215 rep // Set up 216 movsb // segment 217 movl 0x14(%edx),%ecx // Any bytes 218 subl 0x10(%edx),%ecx // to zero? 219 jz start.5 // No 220 xorb %al,%al // Then 221 rep // zero 222 stosb // them 223start.5: popl %ecx // Restore 224 popl %edi // working 225 popl %esi // registers 226 decl %edi // Segments to do 227 je start.7 // If none 228start.6: addl $0x20,%edx // To next entry 229 loop start.4 // Till done | 207 pushl %esi # Save 208 pushl %edi # working 209 pushl %ecx # registers 210 movl 0x4(%edx),%esi # Get p_offset 211 addl %ebx,%esi # as pointer 212 movl 0x8(%edx),%edi # Get p_vaddr 213 addl %ebp,%edi # as pointer 214 movl 0x10(%edx),%ecx # Get p_filesz 215 rep # Set up 216 movsb # segment 217 movl 0x14(%edx),%ecx # Any bytes 218 subl 0x10(%edx),%ecx # to zero? 219 jz start.5 # No 220 xorb %al,%al # Then 221 rep # zero 222 stosb # them 223start.5: popl %ecx # Restore 224 popl %edi # working 225 popl %esi # registers 226 decl %edi # Segments to do 227 je start.7 # If none 228start.6: addl $0x20,%edx # To next entry 229 loop start.4 # Till done |
| 230start.7: 231#ifdef BTXLDR_VERBOSE | 230start.7: 231#ifdef BTXLDR_VERBOSE |
| 232 movl $m_done,%esi // Display done 233 call putstr // message | 232 movl $m_done,%esi # Display done 233 call putstr # message |
| 234#endif | 234#endif |
| 235 movl $start.8,%esi // Real mode stub 236 movl $MEM_STUB,%edi // Destination 237 movl $start.9-start.8,%ecx // Size 238 rep // Relocate 239 movsb // it 240 ljmp $SEL_RCODE,$MEM_STUB // To 16-bit code | 235 movl $start.8,%esi # Real mode stub 236 movl $MEM_STUB,%edi # Destination 237 movl $start.9-start.8,%ecx # Size 238 rep # Relocate 239 movsb # it 240 ljmp $SEL_RCODE,$MEM_STUB # To 16-bit code |
| 241 .code16 | 241 .code16 |
| 242start.8: xorw %ax,%ax // Data 243 movb $SEL_RDATA,%al // selector 244 movw %ax,%ss // Reload SS 245 movw %ax,%ds // Reset 246 movw %ax,%es // other 247 movw %ax,%fs // segment 248 movw %ax,%gs // limits 249 movl %cr0,%eax // Switch to 250 decw %ax // real 251 movl %eax,%cr0 // mode 252 ljmp $0,$MEM_ENTRY // Jump to BTX entry point | 242start.8: xorw %ax,%ax # Data 243 movb $SEL_RDATA,%al # selector 244 movw %ax,%ss # Reload SS 245 movw %ax,%ds # Reset 246 movw %ax,%es # other 247 movw %ax,%fs # segment 248 movw %ax,%gs # limits 249 movl %cr0,%eax # Switch to 250 decw %ax # real 251 movl %eax,%cr0 # mode 252 ljmp $0,$MEM_ENTRY # Jump to BTX entry point |
| 253start.9: 254 .code32 255/* 256 * Output message [ESI] followed by EAX in hex. 257 */ | 253start.9: 254 .code32 255/* 256 * Output message [ESI] followed by EAX in hex. 257 */ |
| 258hexout: pushl %eax // Save 259 call putstr // Display message 260 popl %eax // Restore 261 pushl %esi // Save 262 pushl %edi // caller's 263 movl $buf,%edi // Buffer 264 pushl %edi // Save 265 call hex32 // To hex 266 xorb %al,%al // Terminate 267 stosb // string 268 popl %esi // Restore 269hexout.1: lodsb // Get a char 270 cmpb $'0',%al // Leading zero? 271 je hexout.1 // Yes 272 testb %al,%al // End of string? 273 jne hexout.2 // No 274 decl %esi // Undo 275hexout.2: decl %esi // Adjust for inc 276 call putstr // Display hex 277 popl %edi // Restore 278 popl %esi // caller's 279 ret // To caller | 258hexout: pushl %eax # Save 259 call putstr # Display message 260 popl %eax # Restore 261 pushl %esi # Save 262 pushl %edi # caller's 263 movl $buf,%edi # Buffer 264 pushl %edi # Save 265 call hex32 # To hex 266 xorb %al,%al # Terminate 267 stosb # string 268 popl %esi # Restore 269hexout.1: lodsb # Get a char 270 cmpb $'0',%al # Leading zero? 271 je hexout.1 # Yes 272 testb %al,%al # End of string? 273 jne hexout.2 # No 274 decl %esi # Undo 275hexout.2: decl %esi # Adjust for inc 276 call putstr # Display hex 277 popl %edi # Restore 278 popl %esi # caller's 279 ret # To caller |
| 280/* 281 * Output zero-terminated string [ESI] to the console. 282 */ | 280/* 281 * Output zero-terminated string [ESI] to the console. 282 */ |
| 283putstr.0: call putchr // Output char 284putstr: lodsb // Load char 285 testb %al,%al // End of string? 286 jne putstr.0 // No 287 ret // To caller | 283putstr.0: call putchr # Output char 284putstr: lodsb # Load char 285 testb %al,%al # End of string? 286 jne putstr.0 # No 287 ret # To caller |
| 288/* 289 * Output character AL to the console. 290 */ | 288/* 289 * Output character AL to the console. 290 */ |
| 291putchr: pusha // Save 292 xorl %ecx,%ecx // Zero for loops 293 movb $SCR_MAT,%ah // Mode/attribute 294 movl $BDA_POS,%ebx // BDA pointer 295 movw (%ebx),%dx // Cursor position 296 movl $0xb8000,%edi // Regen buffer (color) 297 cmpb %ah,BDA_SCR-BDA_POS(%ebx) // Mono mode? 298 jne putchr.1 // No 299 xorw %di,%di // Regen buffer (mono) 300putchr.1: cmpb $0xa,%al // New line? 301 je putchr.2 // Yes 302 xchgl %eax,%ecx // Save char 303 movb $SCR_COL,%al // Columns per row 304 mulb %dh // * row position 305 addb %dl,%al // + column 306 adcb $0x0,%ah // position 307 shll %eax // * 2 308 xchgl %eax,%ecx // Swap char, offset 309 movw %ax,(%edi,%ecx,1) // Write attr:char 310 incl %edx // Bump cursor 311 cmpb $SCR_COL,%dl // Beyond row? 312 jb putchr.3 // No 313putchr.2: xorb %dl,%dl // Zero column 314 incb %dh // Bump row 315putchr.3: cmpb $SCR_ROW,%dh // Beyond screen? 316 jb putchr.4 // No 317 leal 2*SCR_COL(%edi),%esi // New top line 318 movw $(SCR_ROW-1)*SCR_COL/2,%cx // Words to move 319 rep // Scroll 320 movsl // screen 321 movb $' ',%al // Space 322 movb $SCR_COL,%cl // Columns to clear 323 rep // Clear 324 stosw // line 325 movb $SCR_ROW-1,%dh // Bottom line 326putchr.4: movw %dx,(%ebx) // Update position 327 popa // Restore 328 ret // To caller | 291putchr: pusha # Save 292 xorl %ecx,%ecx # Zero for loops 293 movb $SCR_MAT,%ah # Mode/attribute 294 movl $BDA_POS,%ebx # BDA pointer 295 movw (%ebx),%dx # Cursor position 296 movl $0xb8000,%edi # Regen buffer (color) 297 cmpb %ah,BDA_SCR-BDA_POS(%ebx) # Mono mode? 298 jne putchr.1 # No 299 xorw %di,%di # Regen buffer (mono) 300putchr.1: cmpb $0xa,%al # New line? 301 je putchr.2 # Yes 302 xchgl %eax,%ecx # Save char 303 movb $SCR_COL,%al # Columns per row 304 mulb %dh # * row position 305 addb %dl,%al # + column 306 adcb $0x0,%ah # position 307 shll %eax # * 2 308 xchgl %eax,%ecx # Swap char, offset 309 movw %ax,(%edi,%ecx,1) # Write attr:char 310 incl %edx # Bump cursor 311 cmpb $SCR_COL,%dl # Beyond row? 312 jb putchr.3 # No 313putchr.2: xorb %dl,%dl # Zero column 314 incb %dh # Bump row 315putchr.3: cmpb $SCR_ROW,%dh # Beyond screen? 316 jb putchr.4 # No 317 leal 2*SCR_COL(%edi),%esi # New top line 318 movw $(SCR_ROW-1)*SCR_COL/2,%cx # Words to move 319 rep # Scroll 320 movsl # screen 321 movb $' ',%al # Space 322 movb $SCR_COL,%cl # Columns to clear 323 rep # Clear 324 stosw # line 325 movb $SCR_ROW-1,%dh # Bottom line 326putchr.4: movw %dx,(%ebx) # Update position 327 popa # Restore 328 ret # To caller |
| 329/* 330 * Convert EAX, AX, or AL to hex, saving the result to [EDI]. 331 */ | 329/* 330 * Convert EAX, AX, or AL to hex, saving the result to [EDI]. 331 */ |
| 332hex32: pushl %eax // Save 333 shrl $0x10,%eax // Do upper 334 call hex16 // 16 335 popl %eax // Restore 336hex16: call hex16.1 // Do upper 8 337hex16.1: xchgb %ah,%al // Save/restore 338hex8: pushl %eax // Save 339 shrb $0x4,%al // Do upper 340 call hex8.1 // 4 341 popl %eax // Restore 342hex8.1: andb $0xf,%al // Get lower 4 343 cmpb $0xa,%al // Convert 344 sbbb $0x69,%al // to hex 345 das // digit 346 orb $0x20,%al // To lower case 347 stosb // Save char 348 ret // (Recursive) | 332hex32: pushl %eax # Save 333 shrl $0x10,%eax # Do upper 334 call hex16 # 16 335 popl %eax # Restore 336hex16: call hex16.1 # Do upper 8 337hex16.1: xchgb %ah,%al # Save/restore 338hex8: pushl %eax # Save 339 shrb $0x4,%al # Do upper 340 call hex8.1 # 4 341 popl %eax # Restore 342hex8.1: andb $0xf,%al # Get lower 4 343 cmpb $0xa,%al # Convert 344 sbbb $0x69,%al # to hex 345 das # digit 346 orb $0x20,%al # To lower case 347 stosb # Save char 348 ret # (Recursive) |
| 349 350 .data 351 .p2align 4 352/* 353 * Global descriptor table. 354 */ | 349 350 .data 351 .p2align 4 352/* 353 * Global descriptor table. 354 */ |
| 355gdt: .word 0x0,0x0,0x0,0x0 // Null entry 356 .word 0xffff,0x0,0x9a00,0xcf // SEL_SCODE 357 .word 0xffff,0x0,0x9200,0xcf // SEL_SDATA 358 .word 0xffff,0x0,0x9a00,0x0 // SEL_RCODE 359 .word 0xffff,0x0,0x9200,0x0 // SEL_RDATA | 355gdt: .word 0x0,0x0,0x0,0x0 # Null entry 356 .word 0xffff,0x0,0x9a00,0xcf # SEL_SCODE 357 .word 0xffff,0x0,0x9200,0xcf # SEL_SDATA 358 .word 0xffff,0x0,0x9a00,0x0 # SEL_RCODE 359 .word 0xffff,0x0,0x9200,0x0 # SEL_RDATA |
| 360gdt.1: | 360gdt.1: |
| 361gdtdesc: .word gdt.1-gdt-1 // Limit 362 .long gdt // Base | 361gdtdesc: .word gdt.1-gdt-1 # Limit 362 .long gdt # Base |
| 363/* 364 * Messages. 365 */ 366m_logo: .asciz " \nBTX loader 1.00 " 367m_vers: .asciz "BTX version is \0\n" 368e_fmt: .asciz "Error: Client format not supported\n" 369#ifdef BTXLDR_VERBOSE 370m_mem: .asciz "Starting in protected mode (base mem=\0)\n" --- 17 unchanged lines hidden (view full) --- 388 .asciz " vaddr=" 389 .asciz " filesz=" 390 .asciz " memsz=\0\n" 391m_done: .asciz "Loading complete\n" 392#endif 393/* 394 * Uninitialized data area. 395 */ | 363/* 364 * Messages. 365 */ 366m_logo: .asciz " \nBTX loader 1.00 " 367m_vers: .asciz "BTX version is \0\n" 368e_fmt: .asciz "Error: Client format not supported\n" 369#ifdef BTXLDR_VERBOSE 370m_mem: .asciz "Starting in protected mode (base mem=\0)\n" --- 17 unchanged lines hidden (view full) --- 388 .asciz " vaddr=" 389 .asciz " filesz=" 390 .asciz " memsz=\0\n" 391m_done: .asciz "Loading complete\n" 392#endif 393/* 394 * Uninitialized data area. 395 */ |
| 396buf: // Scratch buffer | 396buf: # Scratch buffer |