| btxldr.S (125780) | btxldr.S (128710) |
|---|---|
| 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/pc98/btx/btxldr/btxldr.S 128710 2004-04-28 10:15:31Z ru $ 16 */ |
| 15 | 17 |
| 16# $FreeBSD: head/sys/boot/pc98/btx/btxldr/btxldr.S 125780 2004-02-13 15:39:59Z nyan $ | 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 */ |
| 17 | 22 |
| 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# | 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#ifdef PC98 47 .set SCR_MAT,0xe1 # Mode/attribute 48#else 49 .set SCR_MAT,0x7 # Mode/attribute 50#endif 51 .set SCR_COL,0x50 # Columns per row 52 .set SCR_ROW,0x19 # Rows per screen | 46#ifdef PC98 47 .set SCR_MAT,0xe1 # Mode/attribute 48#else 49 .set SCR_MAT,0x7 # Mode/attribute 50#endif 51 .set SCR_COL,0x50 # Columns per row 52 .set SCR_ROW,0x19 # Rows per screen |
| 53# 54# BIOS Data Area locations. 55# | 53/* 54 * BIOS Data Area locations. 55 */ |
| 56#ifdef PC98 57 .set BDA_MEM,0xa1501 # Free memory 58 .set BDA_POS,0xa153e # Cursor position 59#else 60 .set BDA_MEM,0x413 # Free memory 61 .set BDA_SCR,0x449 # Video mode 62 .set BDA_POS,0x450 # Cursor position 63#endif | 56#ifdef PC98 57 .set BDA_MEM,0xa1501 # Free memory 58 .set BDA_POS,0xa153e # Cursor position 59#else 60 .set BDA_MEM,0x413 # Free memory 61 .set BDA_SCR,0x449 # Video mode 62 .set BDA_POS,0x450 # Cursor position 63#endif |
| 64# 65# Required by aout gas inadequacy. 66# | 64/* 65 * Required by aout gas inadequacy. 66 */ |
| 67 .set SIZ_STUB,0x1a # Size of stub | 67 .set SIZ_STUB,0x1a # Size of stub |
| 68# 69# We expect to be loaded by boot2 at the origin defined in ./Makefile. 70# | 68/* 69 * We expect to be loaded by boot2 at the origin defined in ./Makefile. 70 */ |
| 71 .globl start | 71 .globl start |
| 72# 73# BTX program loader for ELF clients. 74# | 72/* 73 * BTX program loader for ELF clients. 74 */ |
| 75start: cld # String ops inc 76#ifdef PC98 77 cli 78gdcwait.1: inb $0x60,%al 79 testb $0x04,%al 80 jz gdcwait.1 81 movb $0xe0,%al 82 outb %al,$0x62 --- 24 unchanged lines hidden (view full) --- 107#endif 108 movl %eax,%ebp # Base of user stack 109#ifdef BTXLDR_VERBOSE 110 movl $m_mem,%esi # Display 111 call hexout # amount of 112 call putstr # base memory 113#endif 114 lgdt gdtdesc # Load new GDT | 75start: cld # String ops inc 76#ifdef PC98 77 cli 78gdcwait.1: inb $0x60,%al 79 testb $0x04,%al 80 jz gdcwait.1 81 movb $0xe0,%al 82 outb %al,$0x62 --- 24 unchanged lines hidden (view full) --- 107#endif 108 movl %eax,%ebp # Base of user stack 109#ifdef BTXLDR_VERBOSE 110 movl $m_mem,%esi # Display 111 call hexout # amount of 112 call putstr # base memory 113#endif 114 lgdt gdtdesc # Load new GDT |
| 115# 116# Relocate caller's arguments. 117# | 115/* 116 * Relocate caller's arguments. 117 */ |
| 118#ifdef BTXLDR_VERBOSE 119 movl $m_esp,%esi # Display 120 movl %esp,%eax # caller 121 call hexout # stack 122 call putstr # pointer 123 movl $m_args,%esi # Format string 124 leal 0x4(%esp,1),%ebx # First argument 125 movl $0x6,%ecx # Count --- 25 unchanged lines hidden (view full) --- 151 rep # Copy 152 movsb # them 153#ifdef BTXLDR_VERBOSE 154 movl $m_rel_args,%esi # Display 155 movl %ebp,%eax # argument 156 call hexout # relocation 157 call putstr # message 158#endif | 118#ifdef BTXLDR_VERBOSE 119 movl $m_esp,%esi # Display 120 movl %esp,%eax # caller 121 call hexout # stack 122 call putstr # pointer 123 movl $m_args,%esi # Format string 124 leal 0x4(%esp,1),%ebx # First argument 125 movl $0x6,%ecx # Count --- 25 unchanged lines hidden (view full) --- 151 rep # Copy 152 movsb # them 153#ifdef BTXLDR_VERBOSE 154 movl $m_rel_args,%esi # Display 155 movl %ebp,%eax # argument 156 call hexout # relocation 157 call putstr # message 158#endif |
| 159# 160# Set up BTX kernel. 161# | 159/* 160 * Set up BTX kernel. 161 */ |
| 162 movl $MEM_ESP,%esp # Set up new stack 163 movl $MEM_DATA,%ebx # Data segment 164 movl $m_vers,%esi # Display BTX 165 call putstr # version message 166 movb 0x5(%ebx),%al # Get major version 167 addb $'0',%al # Display 168 call putchr # it 169 movb $'.',%al # And a --- 35 unchanged lines hidden (view full) --- 205#endif 206 addl $PAG_SIZ,%ebp # Display 207#ifdef BTXLDR_VERBOSE 208 movl $m_base,%esi # the 209 movl %ebp,%eax # user 210 call hexout # base 211 call putstr # address 212#endif | 162 movl $MEM_ESP,%esp # Set up new stack 163 movl $MEM_DATA,%ebx # Data segment 164 movl $m_vers,%esi # Display BTX 165 call putstr # version message 166 movb 0x5(%ebx),%al # Get major version 167 addb $'0',%al # Display 168 call putchr # it 169 movb $'.',%al # And a --- 35 unchanged lines hidden (view full) --- 205#endif 206 addl $PAG_SIZ,%ebp # Display 207#ifdef BTXLDR_VERBOSE 208 movl $m_base,%esi # the 209 movl %ebp,%eax # user 210 call hexout # base 211 call putstr # address 212#endif |
| 213# 214# Set up ELF-format client program. 215# | 213/* 214 * Set up ELF-format client program. 215 */ |
| 216 cmpl $0x464c457f,(%ebx) # ELF magic number? 217 je start.3 # Yes 218 movl $e_fmt,%esi # Display error 219 call putstr # message 220start.2: jmp start.2 # Hang 221start.3: 222#ifdef BTXLDR_VERBOSE 223 movl $m_elf,%esi # Display ELF --- 60 unchanged lines hidden (view full) --- 284 movw %ax,%fs # segment 285 movw %ax,%gs # limits 286 movl %cr0,%eax # Switch to 287 decw %ax # real 288 movl %eax,%cr0 # mode 289 ljmp $0,$MEM_ENTRY # Jump to BTX entry point 290start.9: 291 .code32 | 216 cmpl $0x464c457f,(%ebx) # ELF magic number? 217 je start.3 # Yes 218 movl $e_fmt,%esi # Display error 219 call putstr # message 220start.2: jmp start.2 # Hang 221start.3: 222#ifdef BTXLDR_VERBOSE 223 movl $m_elf,%esi # Display ELF --- 60 unchanged lines hidden (view full) --- 284 movw %ax,%fs # segment 285 movw %ax,%gs # limits 286 movl %cr0,%eax # Switch to 287 decw %ax # real 288 movl %eax,%cr0 # mode 289 ljmp $0,$MEM_ENTRY # Jump to BTX entry point 290start.9: 291 .code32 |
| 292# 293# Output message [ESI] followed by EAX in hex. 294# | 292/* 293 * Output message [ESI] followed by EAX in hex. 294 */ |
| 295hexout: pushl %eax # Save 296 call putstr # Display message 297 popl %eax # Restore 298 pushl %esi # Save 299 pushl %edi # caller's 300 movl $buf,%edi # Buffer 301 pushl %edi # Save 302 call hex32 # To hex --- 6 unchanged lines hidden (view full) --- 309 testb %al,%al # End of string? 310 jne hexout.2 # No 311 decl %esi # Undo 312hexout.2: decl %esi # Adjust for inc 313 call putstr # Display hex 314 popl %edi # Restore 315 popl %esi # caller's 316 ret # To caller | 295hexout: pushl %eax # Save 296 call putstr # Display message 297 popl %eax # Restore 298 pushl %esi # Save 299 pushl %edi # caller's 300 movl $buf,%edi # Buffer 301 pushl %edi # Save 302 call hex32 # To hex --- 6 unchanged lines hidden (view full) --- 309 testb %al,%al # End of string? 310 jne hexout.2 # No 311 decl %esi # Undo 312hexout.2: decl %esi # Adjust for inc 313 call putstr # Display hex 314 popl %edi # Restore 315 popl %esi # caller's 316 ret # To caller |
| 317# 318# Output zero-terminated string [ESI] to the console. 319# | 317/* 318 * Output zero-terminated string [ESI] to the console. 319 */ |
| 320putstr.0: call putchr # Output char 321putstr: lodsb # Load char 322 testb %al,%al # End of string? 323 jne putstr.0 # No 324 ret # To caller | 320putstr.0: call putchr # Output char 321putstr: lodsb # Load char 322 testb %al,%al # End of string? 323 jne putstr.0 # No 324 ret # To caller |
| 325# 326# Output character AL to the console. 327# | 325/* 326 * Output character AL to the console. 327 */ |
| 328putchr: pusha # Save 329 xorl %ecx,%ecx # Zero for loops 330 movb $SCR_MAT,%ah # Mode/attribute 331 movl $BDA_POS,%ebx # BDA pointer 332 movw (%ebx),%dx # Cursor position 333#ifdef PC98 334 movl $0xa0000,%edi # Regen buffer (color) 335#else --- 60 unchanged lines hidden (view full) --- 396 movb %dh,%al 397 outb %al,$0x60 398#else 399 movb $SCR_ROW-1,%dh # Bottom line 400putchr.4: movw %dx,(%ebx) # Update position 401#endif 402 popa # Restore 403 ret # To caller | 328putchr: pusha # Save 329 xorl %ecx,%ecx # Zero for loops 330 movb $SCR_MAT,%ah # Mode/attribute 331 movl $BDA_POS,%ebx # BDA pointer 332 movw (%ebx),%dx # Cursor position 333#ifdef PC98 334 movl $0xa0000,%edi # Regen buffer (color) 335#else --- 60 unchanged lines hidden (view full) --- 396 movb %dh,%al 397 outb %al,$0x60 398#else 399 movb $SCR_ROW-1,%dh # Bottom line 400putchr.4: movw %dx,(%ebx) # Update position 401#endif 402 popa # Restore 403 ret # To caller |
| 404# 405# Convert EAX, AX, or AL to hex, saving the result to [EDI]. 406# | 404/* 405 * Convert EAX, AX, or AL to hex, saving the result to [EDI]. 406 */ |
| 407hex32: pushl %eax # Save 408 shrl $0x10,%eax # Do upper 409 call hex16 # 16 410 popl %eax # Restore 411hex16: call hex16.1 # Do upper 8 412hex16.1: xchgb %ah,%al # Save/restore 413hex8: pushl %eax # Save 414 shrb $0x4,%al # Do upper --- 4 unchanged lines hidden (view full) --- 419 sbbb $0x69,%al # to hex 420 das # digit 421 orb $0x20,%al # To lower case 422 stosb # Save char 423 ret # (Recursive) 424 425 .data 426 .p2align 4 | 407hex32: pushl %eax # Save 408 shrl $0x10,%eax # Do upper 409 call hex16 # 16 410 popl %eax # Restore 411hex16: call hex16.1 # Do upper 8 412hex16.1: xchgb %ah,%al # Save/restore 413hex8: pushl %eax # Save 414 shrb $0x4,%al # Do upper --- 4 unchanged lines hidden (view full) --- 419 sbbb $0x69,%al # to hex 420 das # digit 421 orb $0x20,%al # To lower case 422 stosb # Save char 423 ret # (Recursive) 424 425 .data 426 .p2align 4 |
| 427# 428# Global descriptor table. 429# | 427/* 428 * Global descriptor table. 429 */ |
| 430gdt: .word 0x0,0x0,0x0,0x0 # Null entry 431 .word 0xffff,0x0,0x9a00,0xcf # SEL_SCODE 432 .word 0xffff,0x0,0x9200,0xcf # SEL_SDATA 433 .word 0xffff,0x0,0x9a00,0x0 # SEL_RCODE 434 .word 0xffff,0x0,0x9200,0x0 # SEL_RDATA 435gdt.1: 436gdtdesc: .word gdt.1-gdt-1 # Limit 437 .long gdt # Base | 430gdt: .word 0x0,0x0,0x0,0x0 # Null entry 431 .word 0xffff,0x0,0x9a00,0xcf # SEL_SCODE 432 .word 0xffff,0x0,0x9200,0xcf # SEL_SDATA 433 .word 0xffff,0x0,0x9a00,0x0 # SEL_RCODE 434 .word 0xffff,0x0,0x9200,0x0 # SEL_RDATA 435gdt.1: 436gdtdesc: .word gdt.1-gdt-1 # Limit 437 .long gdt # Base |
| 438# 439# Messages. 440# | 438/* 439 * Messages. 440 */ |
| 441m_logo: .asciz " \nBTX loader 1.00 " 442m_vers: .asciz "BTX version is \0\n" 443e_fmt: .asciz "Error: Client format not supported\n" 444#ifdef BTXLDR_VERBOSE 445m_mem: .asciz "Starting in protected mode (base mem=\0)\n" 446m_esp: .asciz "Arguments passed (esp=\0):\n" 447m_args: .asciz"<howto=" 448 .asciz" bootdev=" --- 11 unchanged lines hidden (view full) --- 460 .asciz " filesz=" 461 .asciz " memsz=\0\n" 462 .asciz "data segment: offset=" 463 .asciz " vaddr=" 464 .asciz " filesz=" 465 .asciz " memsz=\0\n" 466m_done: .asciz "Loading complete\n" 467#endif | 441m_logo: .asciz " \nBTX loader 1.00 " 442m_vers: .asciz "BTX version is \0\n" 443e_fmt: .asciz "Error: Client format not supported\n" 444#ifdef BTXLDR_VERBOSE 445m_mem: .asciz "Starting in protected mode (base mem=\0)\n" 446m_esp: .asciz "Arguments passed (esp=\0):\n" 447m_args: .asciz"<howto=" 448 .asciz" bootdev=" --- 11 unchanged lines hidden (view full) --- 460 .asciz " filesz=" 461 .asciz " memsz=\0\n" 462 .asciz "data segment: offset=" 463 .asciz " vaddr=" 464 .asciz " filesz=" 465 .asciz " memsz=\0\n" 466m_done: .asciz "Loading complete\n" 467#endif |
| 468# 469# Uninitialized data area. 470# | 468/* 469 * Uninitialized data area. 470 */ |
| 471buf: # Scratch buffer | 471buf: # Scratch buffer |