diff options
Diffstat (limited to 'qemu/roms/ipxe/src/arch/i386/prefix/libprefix.S')
| -rw-r--r-- | qemu/roms/ipxe/src/arch/i386/prefix/libprefix.S | 969 |
1 files changed, 969 insertions, 0 deletions
diff --git a/qemu/roms/ipxe/src/arch/i386/prefix/libprefix.S b/qemu/roms/ipxe/src/arch/i386/prefix/libprefix.S new file mode 100644 index 000000000..7c1ece791 --- /dev/null +++ b/qemu/roms/ipxe/src/arch/i386/prefix/libprefix.S @@ -0,0 +1,969 @@ +/* + * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + * + */ + +FILE_LICENCE ( GPL2_OR_LATER ) + + .arch i386 + +/* Image compression enabled */ +#define COMPRESS 1 + +/* Protected mode flag */ +#define CR0_PE 1 + +/* Allow for DBG()-style messages within libprefix */ +#ifdef NDEBUG + .macro progress message + .endm +#else + .macro progress message + pushfl + pushw %ds + pushw %si + pushw %di + pushw %cs + popw %ds + xorw %di, %di + movw $progress_\@, %si + call print_message + popw %di + popw %si + popw %ds + popfl + .section ".prefix.data", "aw", @progbits +progress_\@: + .asciz "\message" + .size progress_\@, . - progress_\@ + .previous + .endm +#endif + +/***************************************************************************** + * Utility function: print character (with LF -> LF,CR translation) + * + * Parameters: + * %al : character to print + * %ds:di : output buffer (or %di=0 to print to console) + * Returns: + * %ds:di : next character in output buffer (if applicable) + ***************************************************************************** + */ + .section ".prefix.lib", "awx", @progbits + .code16 + .globl print_character +print_character: + /* Preserve registers */ + pushw %ax + pushw %bx + pushw %bp + /* If %di is non-zero, write character to buffer and exit */ + testw %di, %di + jz 1f + movb %al, %ds:(%di) + incw %di + jmp 3f +1: /* Print character */ + movw $0x0007, %bx /* page 0, attribute 7 (normal) */ + movb $0x0e, %ah /* write char, tty mode */ + cmpb $0x0a, %al /* '\n'? */ + jne 2f + int $0x10 + movb $0x0d, %al +2: int $0x10 + /* Restore registers and return */ +3: popw %bp + popw %bx + popw %ax + ret + .size print_character, . - print_character + +/***************************************************************************** + * Utility function: print space + * + * Parameters: + * %ds:di : output buffer (or %di=0 to print to console) + * Returns: + * %ds:di : next character in output buffer (if applicable) + ***************************************************************************** + */ + .section ".prefix.lib", "awx", @progbits + .code16 + .globl print_space +print_space: + /* Preserve registers */ + pushw %ax + /* Print space */ + movb $( ' ' ), %al + call print_character + /* Restore registers and return */ + popw %ax + ret + .size print_space, . - print_space + +/***************************************************************************** + * Utility function: print a NUL-terminated string + * + * Parameters: + * %ds:si : string to print + * %ds:di : output buffer (or %di=0 to print to console) + * Returns: + * %ds:si : character after terminating NUL + * %ds:di : next character in output buffer (if applicable) + ***************************************************************************** + */ + .section ".prefix.lib", "awx", @progbits + .code16 + .globl print_message +print_message: + /* Preserve registers */ + pushw %ax + /* Print string */ +1: lodsb + testb %al, %al + je 2f + call print_character + jmp 1b +2: /* Restore registers and return */ + popw %ax + ret + .size print_message, . - print_message + +/***************************************************************************** + * Utility functions: print hex digit/byte/word/dword + * + * Parameters: + * %al (low nibble) : digit to print + * %al : byte to print + * %ax : word to print + * %eax : dword to print + * %ds:di : output buffer (or %di=0 to print to console) + * Returns: + * %ds:di : next character in output buffer (if applicable) + ***************************************************************************** + */ + .section ".prefix.lib", "awx", @progbits + .code16 + .globl print_hex_dword +print_hex_dword: + rorl $16, %eax + call print_hex_word + rorl $16, %eax + /* Fall through */ + .size print_hex_dword, . - print_hex_dword + .globl print_hex_word +print_hex_word: + xchgb %al, %ah + call print_hex_byte + xchgb %al, %ah + /* Fall through */ + .size print_hex_word, . - print_hex_word + .globl print_hex_byte +print_hex_byte: + rorb $4, %al + call print_hex_nibble + rorb $4, %al + /* Fall through */ + .size print_hex_byte, . - print_hex_byte + .globl print_hex_nibble +print_hex_nibble: + /* Preserve registers */ + pushw %ax + /* Print digit (technique by Norbert Juffa <norbert.juffa@amd.com> */ + andb $0x0f, %al + cmpb $10, %al + sbbb $0x69, %al + das + call print_character + /* Restore registers and return */ + popw %ax + ret + .size print_hex_nibble, . - print_hex_nibble + +/***************************************************************************** + * Utility function: print PCI bus:dev.fn + * + * Parameters: + * %ax : PCI bus:dev.fn to print + * %ds:di : output buffer (or %di=0 to print to console) + * Returns: + * %ds:di : next character in output buffer (if applicable) + ***************************************************************************** + */ + .section ".prefix.lib", "awx", @progbits + .code16 + .globl print_pci_busdevfn +print_pci_busdevfn: + /* Preserve registers */ + pushw %ax + /* Print bus */ + xchgb %al, %ah + call print_hex_byte + /* Print ":" */ + movb $( ':' ), %al + call print_character + /* Print device */ + movb %ah, %al + shrb $3, %al + call print_hex_byte + /* Print "." */ + movb $( '.' ), %al + call print_character + /* Print function */ + movb %ah, %al + andb $0x07, %al + call print_hex_nibble + /* Restore registers and return */ + popw %ax + ret + .size print_pci_busdevfn, . - print_pci_busdevfn + +/***************************************************************************** + * Utility function: clear current line + * + * Parameters: + * %ds:di : output buffer (or %di=0 to print to console) + * Returns: + * %ds:di : next character in output buffer (if applicable) + ***************************************************************************** + */ + .section ".prefix.lib", "awx", @progbits + .code16 + .globl print_kill_line +print_kill_line: + /* Preserve registers */ + pushw %ax + pushw %cx + /* Print CR */ + movb $( '\r' ), %al + call print_character + /* Print 79 spaces */ + movw $79, %cx +1: call print_space + loop 1b + /* Print CR */ + call print_character + /* Restore registers and return */ + popw %cx + popw %ax + ret + .size print_kill_line, . - print_kill_line + +/**************************************************************************** + * copy_bytes + * + * Copy bytes + * + * Parameters: + * %ds:esi : source address + * %es:edi : destination address + * %ecx : length + * Returns: + * %ds:esi : next source address + * %es:edi : next destination address + * Corrupts: + * None + **************************************************************************** + */ + .section ".prefix.lib", "awx", @progbits + .code16 +copy_bytes: + pushl %ecx + rep addr32 movsb + popl %ecx + ret + .size copy_bytes, . - copy_bytes + +/**************************************************************************** + * zero_bytes + * + * Zero bytes + * + * Parameters: + * %ds:esi : source address + * %es:edi : destination address + * %ecx : length + * Returns: + * %ds:esi : next source address + * %es:edi : next destination address + * Corrupts: + * None + **************************************************************************** + */ + .section ".prefix.lib", "awx", @progbits + .code16 +zero_bytes: + pushl %ecx + pushw %ax + xorw %ax, %ax + rep addr32 stosb + popw %ax + popl %ecx + ret + .size zero_bytes, . - zero_bytes + +/**************************************************************************** + * process_bytes + * + * Call memcpy()-like function + * + * Parameters: + * %esi : source physical address + * %edi : destination physical address + * %ecx : length + * %bx : memcpy()-like function to call, passing parameters: + * %ds:esi : source address + * %es:edi : destination address + * %ecx : length + * and returning: + * %ds:esi : next source address + * %es:edi : next destination address + * Returns: + * %esi : next source physical address + * %edi : next destination physical address + * Corrupts: + * None + **************************************************************************** + */ + .section ".prefix.lib", "awx", @progbits + .code16 +process_bytes: + +#ifndef KEEP_IT_REAL + + /* Preserve registers */ + pushl %eax + pushl %ebp + + /* Construct GDT on stack (since .prefix may not be writable) */ + .equ PM_DS, 0x18 /* Flat data segment */ + pushl $0x00cf9300 + pushl $0x0000ffff + .equ PM_SS, 0x10 /* Stack segment based at %ss:0000 */ + pushl $0x008f0930 + pushw %ss + pushw $0xffff + .equ PM_CS, 0x08 /* Code segment based at %cs:0000 */ + pushl $0x008f09b0 + pushw %cs + pushw $0xffff + pushl $0 /* Base and length */ + pushw %ss + pushw $0x1f + movzwl %sp, %ebp + shll $4, 0x02(%bp) + addl %ebp, 0x02(%bp) + shll $4, 0x0a(%bp) + shll $4, 0x12(%bp) + subw $8, %sp + sgdt -8(%bp) + + /* Switch to protected mode */ + pushw %gs + pushw %fs + pushw %es + pushw %ds + pushw %ss + pushw %cs + pushw $2f + cli + data32 lgdt (%bp) + movl %cr0, %eax + orb $CR0_PE, %al + movl %eax, %cr0 + ljmp $PM_CS, $1f +1: movw $PM_SS, %ax + movw %ax, %ss + movw $PM_DS, %ax + movw %ax, %ds + movw %ax, %es + movw %ax, %fs + movw %ax, %gs + + /* Call memcpy()-like function */ + call *%bx + + /* Return to (flat) real mode */ + movl %cr0, %eax + andb $0!CR0_PE, %al + movl %eax, %cr0 + lret +2: /* lret will ljmp to here */ + popw %ss + popw %ds + popw %es + popw %fs + popw %gs + + /* Restore GDT */ + data32 lgdt -8(%bp) + addw $( 8 /* saved GDT */ + ( PM_DS + 8 ) /* GDT on stack */ ), %sp + + /* Restore registers and return */ + popl %ebp + popl %eax + ret + +#else /* KEEP_IT_REAL */ + + /* Preserve registers */ + pushl %eax + pushw %ds + pushw %es + + /* Convert %esi and %edi to %ds:esi and %es:edi */ + shrl $4, %esi + movw %si, %ds + xorw %si, %si + shll $4, %esi + shrl $4, %edi + movw %di, %es + xorw %di, %di + shll $4, %edi + + /* Call memcpy()-like function */ + call *%bx + + /* Convert %ds:esi and %es:edi back to physical addresses */ + xorl %eax, %eax + movw %ds, %cx + shll $4, %eax + addl %eax, %esi + xorl %eax, %eax + movw %es, %cx + shll $4, %eax + addl %eax, %edi + + /* Restore registers and return */ + popw %es + popw %ds + popl %eax + ret + +#endif /* KEEP_IT_REAL */ + + .size process_bytes, . - process_bytes + +/**************************************************************************** + * install_block + * + * Install block to specified address + * + * Parameters: + * %esi : source physical address (must be a multiple of 16) + * %edi : destination physical address (must be a multiple of 16) + * %ecx : length of (decompressed) data + * %edx : total length of block (including any uninitialised data portion) + * Returns: + * %esi : next source physical address (will be a multiple of 16) + * %edi : next destination physical address (will be a multiple of 16) + * Corrupts: + * none + **************************************************************************** + */ + .section ".prefix.lib", "awx", @progbits + .code16 +install_block: + /* Preserve registers */ + pushl %ecx + pushw %bx + + /* Decompress (or copy) source to destination */ +#if COMPRESS + movw $decompress16, %bx +#else + movw $copy_bytes, %bx +#endif + call process_bytes + + /* Zero .bss portion */ + negl %ecx + addl %edx, %ecx + movw $zero_bytes, %bx + call process_bytes + + /* Round up %esi and %edi to start of next blocks */ + addl $0xf, %esi + andl $~0xf, %esi + addl $0xf, %edi + andl $~0xf, %edi + + /* Restore registers and return */ + popw %bx + popl %ecx + ret + .size install_block, . - install_block + +/**************************************************************************** + * alloc_basemem + * + * Allocate space for .text16 and .data16 from top of base memory. + * Memory is allocated using the BIOS free base memory counter at + * 0x40:13. + * + * Parameters: + * none + * Returns: + * %ax : .text16 segment address + * %bx : .data16 segment address + * Corrupts: + * none + **************************************************************************** + */ + .section ".prefix.lib", "awx", @progbits + .code16 + .globl alloc_basemem +alloc_basemem: + /* Preserve registers */ + pushw %fs + + /* FBMS => %ax as segment address */ + pushw $0x40 + popw %fs + movw %fs:0x13, %ax + shlw $6, %ax + + /* Calculate .data16 segment address */ + subw $_data16_memsz_pgh, %ax + pushw %ax + + /* Calculate .text16 segment address. Round down to ensure + * low bits are zero, to speed up mode transitions under KVM. + */ + subw $_text16_memsz_pgh, %ax + andb $~0x03, %al + pushw %ax + + /* Update FBMS */ + shrw $6, %ax + movw %ax, %fs:0x13 + + /* Retrieve .text16 and .data16 segment addresses */ + popw %ax + popw %bx + + /* Restore registers and return */ + popw %fs + ret + .size alloc_basemem, . - alloc_basemem + +/**************************************************************************** + * free_basemem + * + * Free space allocated with alloc_basemem. + * + * Parameters: + * none (.text16 segment address is implicit in %cs) + * Returns: + * %ax : 0 if successfully freed + * Corrupts: + * none + **************************************************************************** + */ + .section ".text16", "ax", @progbits + .code16 + .globl free_basemem +free_basemem: + /* Preserve registers */ + pushw %fs + pushw %ax + + /* Check FBMS counter */ + movw %cs, %ax + shrw $6, %ax + pushw $0x40 + popw %fs + cmpw %ax, %fs:0x13 + jne 1f + + /* Check hooked interrupt count */ + cmpw $0, %cs:hooked_bios_interrupts + jne 1f + + /* OK to free memory */ + movw %cs, %ax + addw $_text16_memsz_pgh, %ax + addw $_data16_memsz_pgh, %ax + shrw $6, %ax + movw %ax, %fs:0x13 + xorw %ax, %ax + +1: /* Restore registers and return */ + popw %ax + popw %fs + ret + .size free_basemem, . - free_basemem + + .section ".text16.data", "aw", @progbits + .globl hooked_bios_interrupts +hooked_bios_interrupts: + .word 0 + .size hooked_bios_interrupts, . - hooked_bios_interrupts + +/**************************************************************************** + * install + * + * Install all text and data segments. + * + * Parameters: + * none + * Returns: + * %ax : .text16 segment address + * %bx : .data16 segment address + * Corrupts: + * none + **************************************************************************** + */ + .section ".prefix.lib", "awx", @progbits + .code16 + .globl install +install: + progress "install:\n" + /* Preserve registers */ + pushl %esi + pushl %edi + pushl %ebp + /* Allocate space for .text16 and .data16 */ + call alloc_basemem + /* Image source = %cs:0000 */ + xorl %esi, %esi + /* Image destination = default */ + xorl %edi, %edi + /* Allow arbitrary relocation */ + orl $0xffffffff, %ebp + /* Install text and data segments */ + call install_prealloc + /* Restore registers and return */ + popl %ebp + popl %edi + popl %esi + ret + .size install, . - install + +/**************************************************************************** + * install_prealloc + * + * Install all text and data segments. + * + * Parameters: + * %ax : .text16 segment address + * %bx : .data16 segment address + * %esi : Image source physical address (or zero for %cs:0000) + * %edi : Decompression temporary area physical address (or zero for default) + * %ebp : Maximum end address for relocation + * - 0xffffffff for no maximum + * - 0x00000000 to inhibit use of INT 15,e820 and INT 15,e801 + * Corrupts: + * none + **************************************************************************** + */ + .section ".prefix.lib", "awx", @progbits + .code16 + .globl install_prealloc +install_prealloc: + progress "install_prealloc:\n" + /* Save registers */ + pushal + pushw %ds + pushw %es + cld /* Sanity: clear the direction flag asap */ + + /* Set up %ds for (read-only) access to .prefix */ + pushw %cs + popw %ds + + /* Save decompression temporary area physical address */ + pushl %edi + + /* Install .text16.early and calculate %ecx as offset to next block */ + progress " .text16.early\n" + pushl %esi + xorl %esi, %esi + movw %cs, %si + shll $4, %esi + pushl %esi /* Save original %cs:0000 */ + addl $_text16_early_lma, %esi + movzwl %ax, %edi + shll $4, %edi + movl $_text16_early_filesz, %ecx + movl $_text16_early_memsz, %edx + call install_block /* .text16.early */ + popl %ecx /* Calculate offset to next block */ + subl %esi, %ecx + negl %ecx + popl %esi + +#ifndef KEEP_IT_REAL + /* Access high memory by enabling the A20 gate. (We will + * already have 4GB segment limits as a result of calling + * install_block.) + */ + progress " access_highmem\n" + pushw %cs + pushw $1f + pushw %ax + pushw $access_highmem + lret +1: /* Die if we could not access high memory */ + jnc 3f + movw $a20_death_message, %si + xorw %di, %di + call print_message +2: jmp 2b + .section ".prefix.data", "aw", @progbits +a20_death_message: + .asciz "\nHigh memory inaccessible - cannot continue\n" + .size a20_death_message, . - a20_death_message + .previous +3: +#endif + + /* Open payload (which may not yet be in memory) */ + progress " open_payload\n" + pushw %cs + pushw $1f + pushw %ax + pushw $open_payload + lret +1: /* Die if we could not access the payload */ + jnc 3f + xorw %di, %di + movl %esi, %eax + call print_hex_dword + call print_space + movl %ecx, %eax + call print_hex_dword + movw $payload_death_message, %si + call print_message +2: /* Halt system */ + cli + hlt + jmp 2b + .section ".prefix.data", "aw", @progbits +payload_death_message: + .asciz "\nPayload inaccessible - cannot continue\n" + .size payload_death_message, . - payload_death_message + .previous +3: + + /* Calculate physical address of payload (i.e. first source) */ + testl %esi, %esi + jnz 1f + movw %cs, %si + shll $4, %esi +1: addl %ecx, %esi + + /* Install .text16.late and .data16 */ + progress " .text16.late\n" + movl $_text16_late_filesz, %ecx + movl $_text16_late_memsz, %edx + call install_block /* .text16.late */ + progress " .data16\n" + movzwl %bx, %edi + shll $4, %edi + movl $_data16_filesz, %ecx + movl $_data16_memsz, %edx + call install_block /* .data16 */ + + /* Set up %ds for access to .data16 */ + movw %bx, %ds + + /* Restore decompression temporary area physical address */ + popl %edi + +#ifdef KEEP_IT_REAL + /* Initialise libkir */ + movw %ax, (init_libkir_vector+2) + lcall *init_libkir_vector +#else + /* Find a suitable decompression temporary area, if none specified */ + pushl %eax + testl %edi, %edi + jnz 1f + /* Use INT 15,88 to find the highest available address via INT + * 15,88. This limits us to around 64MB, which should avoid + * all of the POST-time memory map failure modes. + */ + movb $0x88, %ah + int $0x15 + movw %ax, %di + addl $0x400, %edi + subl $_textdata_memsz_kb, %edi + shll $10, %edi + /* Sanity check: if we have ended up below 1MB, use 1MB */ + cmpl $0x100000, %edi + jae 1f + movl $0x100000, %edi +1: popl %eax + + /* Install .text and .data to temporary area in high memory, + * prior to reading the E820 memory map and relocating + * properly. + */ + progress " .textdata\n" + pushl %edi + movl $_textdata_filesz, %ecx + movl $_textdata_memsz, %edx + call install_block + popl %edi + + /* Initialise librm at current location */ + progress " init_librm\n" + movw %ax, (init_librm_vector+2) + lcall *init_librm_vector + + /* Inhibit INT 15,e820 and INT 15,e801 if applicable */ + testl %ebp, %ebp + jnz 1f + incb memmap_post + decl %ebp +1: + + /* Call relocate() to determine target address for relocation. + * relocate() will return with %esi, %edi and %ecx set up + * ready for the copy to the new location. + */ + progress " relocate\n" + movw %ax, (prot_call_vector+2) + pushl $relocate + lcall *prot_call_vector + popl %edx /* discard */ + + /* Copy code to new location */ + progress " copy\n" + pushl %edi + pushw %bx + movw $copy_bytes, %bx + call process_bytes + popw %bx + popl %edi + + /* Initialise librm at new location */ + progress " init_librm\n" + lcall *init_librm_vector +#endif + + /* Close access to payload */ + progress " close_payload\n" + movw %ax, (close_payload_vector+2) + lcall *close_payload_vector + + /* Restore registers */ + popw %es + popw %ds + popal + ret + .size install_prealloc, . - install_prealloc + + /* Vectors for far calls to .text16 functions. Must be in + * .data16, since .prefix may not be writable. + */ + .section ".data16", "aw", @progbits +#ifdef KEEP_IT_REAL +init_libkir_vector: + .word init_libkir + .word 0 + .size init_libkir_vector, . - init_libkir_vector +#else +init_librm_vector: + .word init_librm + .word 0 + .size init_librm_vector, . - init_librm_vector +prot_call_vector: + .word prot_call + .word 0 + .size prot_call_vector, . - prot_call_vector +#endif +close_payload_vector: + .word close_payload + .word 0 + .size close_payload_vector, . - close_payload_vector + + /* Dummy routines to open and close payload */ + .section ".text16.early.data", "aw", @progbits + .weak open_payload + .weak close_payload +open_payload: +close_payload: + clc + lret + .size open_payload, . - open_payload + .size close_payload, . - close_payload + +/**************************************************************************** + * uninstall + * + * Uninstall all text and data segments. + * + * Parameters: + * none (.text16 segment address is implicit in %cs) + * Returns: + * none + * Corrupts: + * none + **************************************************************************** + */ + .section ".text16", "ax", @progbits + .code16 + .globl uninstall +uninstall: + call free_basemem + ret + .size uninstall, . - uninstall + + + + /* File split information for the compressor */ +#if COMPRESS +#define PACK_OR_COPY "PACK" +#else +#define PACK_OR_COPY "COPY" +#endif + .section ".zinfo", "a", @progbits + .ascii "COPY" + .long _prefix_lma + .long _prefix_filesz + .long _max_align + .ascii PACK_OR_COPY + .long _text16_early_lma + .long _text16_early_filesz + .long _max_align + .ascii "PAYL" + .long 0 + .long 0 + .long _payload_align + .ascii "COPY" + .long _pprefix_lma + .long _pprefix_filesz + .long _max_align + .ascii PACK_OR_COPY + .long _text16_late_lma + .long _text16_late_filesz + .long _max_align + .ascii PACK_OR_COPY + .long _data16_lma + .long _data16_filesz + .long _max_align + .ascii PACK_OR_COPY + .long _textdata_lma + .long _textdata_filesz + .long _max_align + + .weak _payload_align + .equ _payload_align, 1 |