From 10c28a51bdc801374eccec52d1e4d6677100f86d Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Tue, 2 May 2006 20:51:07 +0000 Subject: [PATCH] Create two easy-to-use entry points in libprefix: install and install_prealloc. I *think* these will suffice for all the 16-bit prefixes. --- src/arch/i386/prefix/dskprefix.S | 9 +-- src/arch/i386/prefix/libprefix.S | 109 +++++++++++++++++++++++++++--- src/arch/i386/scripts/i386.lds | 37 +++++----- src/arch/i386/transitions/librm.S | 2 +- 4 files changed, 122 insertions(+), 35 deletions(-) diff --git a/src/arch/i386/prefix/dskprefix.S b/src/arch/i386/prefix/dskprefix.S index 05bf45bc..a2f62198 100644 --- a/src/arch/i386/prefix/dskprefix.S +++ b/src/arch/i386/prefix/dskprefix.S @@ -348,13 +348,7 @@ msg1end: .word 0xAA55 start_runtime: - /* Install .text16 and .data16 to top of base memory */ - call alloc_basemem - call install_basemem - - /* Install .text and .data to 2MB mark */ - movl $(2<<20), %edi - call install_highmem + call install /* Jump to .text16 segment */ pushw %ax @@ -362,7 +356,6 @@ start_runtime: lret .section ".text16", "awx", @progbits 1: - call init_gdt pushl $initialise data32 call prot_call popl %eax /* discard */ diff --git a/src/arch/i386/prefix/libprefix.S b/src/arch/i386/prefix/libprefix.S index 0f7d8a14..e00388d6 100644 --- a/src/arch/i386/prefix/libprefix.S +++ b/src/arch/i386/prefix/libprefix.S @@ -30,11 +30,12 @@ * Parameters: * %esi : byte offset within loaded image (must be a multiple of 16) * %es:edi : destination address - * %ecx : length to install + * %ecx : length of (decompressed) data + * %edx : total length of block (including any uninitialised data portion) * Returns: * none * Corrupts: - * %esi, %edi, %ecx + * %esi, %edi, %ecx, %edx **************************************************************************** */ .section ".prefix.lib" @@ -42,7 +43,7 @@ install_block: /* Preserve registers */ pushw %ds - pushw %ax + pushw %eax /* Starting segment => %ds */ movw %cs, %ax @@ -51,12 +52,22 @@ install_block: movw %ax, %ds xorl %esi, %esi + /* Calculate start and length of uninitialised data portion */ + leal (%edi,%ecx), %eax + subl %ecx, %edx + /* Do the copy */ cld - addr32 rep movsb /* or "call decompress16" */ + rep addr32 movsb /* or "call decompress16" */ + + /* Zero remaining space */ + movl %eax, %edi + movl %edx, %ecx + xorb %al, %al + rep addr32 stosb /* Restore registers */ - popw %ax + popw %eax popw %ds ret .size install_block, . - install_block @@ -79,7 +90,6 @@ install_block: */ .section ".prefix.lib" .code16 - .globl alloc_basemem alloc_basemem: /* FBMS => %ax as segment address */ movw $0x40, %ax @@ -121,19 +131,20 @@ alloc_basemem: */ .section ".prefix.lib" .code16 - .globl install_basemem install_basemem: /* Preserve registers */ pushw %es pushl %esi pushl %edi pushl %ecx + pushl %edx /* Install .text16 */ movw %ax, %es xorl %edi, %edi movl $_text16_load_offset, %esi movl $_text16_size, %ecx + movl %ecx, %edx call install_block /* Install .data16 */ @@ -141,9 +152,11 @@ install_basemem: xorl %edi, %edi movl $_data16_load_offset, %esi movl $_data16_progbits_size, %ecx + movl $_data16_size, %edx call install_block /* Restore registers */ + popl %edx popl %ecx popl %edi popl %esi @@ -160,6 +173,9 @@ install_basemem: * simpler. **************************************************************************** */ + +#ifndef KEEP_IT_REAL + .section ".prefix.lib" .align 16 gdt: @@ -180,6 +196,8 @@ flat_ds: /* Flat real mode data segment */ gdt_end: .equ gdt_length, gdt_end - gdt .size gdt, . - gdt + +#endif /* KEEP_IT_REAL */ /**************************************************************************** * set_segment_limits (real-mode near call) @@ -190,6 +208,9 @@ gdt_end: * %cx : Segment limit ($REAL_DS or $FLAT_DS) **************************************************************************** */ + +#ifndef KEEP_IT_REAL + .section ".prefix.lib" .code16 set_segment_limits: @@ -222,6 +243,8 @@ set_segment_limits: ret .size set_segment_limits, . - set_segment_limits +#endif /* KEEP_IT_REAL */ + /**************************************************************************** * install_highmem (real-mode near call) * @@ -235,15 +258,18 @@ set_segment_limits: * none **************************************************************************** */ + +#ifndef KEEP_IT_REAL + .section ".prefix.lib" .code16 - .globl install_highmem install_highmem: /* Preserve registers and interrupt status */ pushfl pushl %esi pushl %edi pushl %ecx + pushl %edx /* Disable interrupts and flatten real mode */ cli @@ -253,8 +279,9 @@ install_highmem: /* Install .text and .data to specified address */ xorw %cx, %cx movw %cx, %es - movl $_text_load_offset, %esi - movl $_text_progbits_size, %ecx + movl $_textdata_load_offset, %esi + movl $_textdata_progbits_size, %ecx + movl $_textdata_size, %edx call install_block /* Unflatten real mode */ @@ -262,9 +289,71 @@ install_highmem: call set_segment_limits /* Restore registers and interrupt status */ + popl %edx popl %ecx popl %edi popl %esi popfl ret .size install_highmem, . - install_highmem + +#endif /* KEEP_IT_REAL */ + +/**************************************************************************** + * install (real-mode near call) + * install_prealloc (real-mode near call) + * + * Install all text and data segments. + * + * Parameters: + * %ax : .text16 segment address (install_prealloc only) + * %bx : .data16 segment address (install_prealloc only) + * Returns: + * %ax : .text16 segment address + * %bx : .data16 segment address + * %edi : .text physical address (if applicable) + * Corrupts: + * none + **************************************************************************** + */ + .section ".prefix.lib" + .code16 + .globl install +install: + /* Allocate space for .text16 and .data16 */ + call alloc_basemem + .size install, . - install + .globl install_prealloc +install_prealloc: + /* Install .text16 and .data16 */ + call install_basemem + +#ifndef KEEP_IT_REAL + /* Install .text and .data to 2MB mark. Use 2MB to avoid + * problems with A20. + */ + movl $(2<<20), %edi + call install_highmem + + /* Continue executing in .text16 segment */ + pushw %cs + pushw $2f + pushw %ax + pushw $1f + lret + .section ".text16", "awx", @progbits +1: + /* Set up protected-mode GDT, call relocate(), reset GDT */ + call init_gdt + pushl $relocate + data32 call prot_call + addw $4, %sp + call init_gdt + + /* Return to executing in .prefix section */ + lret + .section ".prefix.lib" +2: +#endif + ret + .size install_prealloc, . - install_prealloc diff --git a/src/arch/i386/scripts/i386.lds b/src/arch/i386/scripts/i386.lds index 71a7f74d..d43a68f7 100644 --- a/src/arch/i386/scripts/i386.lds +++ b/src/arch/i386/scripts/i386.lds @@ -20,7 +20,7 @@ SECTIONS { * will default to: * * _prefix_link_addr = 0 - * _text_link_addr = 0 + * _textdata_link_addr = 0 * _load_addr = 0 * _max_align = 16 * @@ -108,11 +108,14 @@ SECTIONS { * The 32-bit sections */ - _text_link_addr = DEFINED ( _text_link_addr ) ? _text_link_addr : 0; - . = _text_link_addr; + _textdata_link_addr = ( DEFINED ( _textdata_link_addr ) ? + _textdata_link_addr : 0 ); + . = _textdata_link_addr; + _textdata = .; + _text = .; - .text : AT ( _text_load_offset + __text ) { + .text : AT ( _textdata_load_offset + __text ) { __text = .; *(.text) *(.text.*) @@ -122,19 +125,19 @@ SECTIONS { _data = .; - .rodata : AT ( _text_load_offset + __rodata ) { + .rodata : AT ( _textdata_load_offset + __rodata ) { __rodata = .; *(.rodata) *(.rodata.*) } - .data : AT ( _text_load_offset + __data ) { + .data : AT ( _textdata_load_offset + __data ) { __data = .; *(.data) *(.data.*) *(SORT(.tbl.*)) /* Various tables. See include/tables.h */ - _etext_progbits = .; + _etextdata_progbits = .; } - .bss : AT ( _text_load_offset + __bss ) { + .bss : AT ( _textdata_load_offset + __bss ) { __bss = .; _bss = .; *(.bss) @@ -142,7 +145,7 @@ SECTIONS { *(COMMON) _ebss = .; } - .stack : AT ( _text_load_offset + __stack ) { + .stack : AT ( _textdata_load_offset + __stack ) { __stack = .; *(.stack) *(.stack.*) @@ -150,6 +153,8 @@ SECTIONS { _edata = .; + _etextdata = .; + _end = .; /* @@ -194,12 +199,12 @@ SECTIONS { _data16_progbits_size = _edata16_progbits - _data16; . = _data16_load_addr + _data16_progbits_size; - . -= _text_link_addr; - _text_load_offset = ALIGN ( _max_align ); - _text_load_addr = _text_link_addr + _text_load_offset; - _text_size = _etext - _text; - _text_progbits_size = _etext_progbits - _text; - . = _text_load_addr + _text_progbits_size; + . -= _textdata_link_addr; + _textdata_load_offset = ALIGN ( _max_align ); + _textdata_load_addr = _textdata_link_addr + _textdata_load_offset; + _textdata_size = _etextdata - _textdata; + _textdata_progbits_size = _etextdata_progbits - _textdata; + . = _textdata_load_addr + _textdata_progbits_size; . = ALIGN ( _max_align ); @@ -223,7 +228,7 @@ SECTIONS { _assert = ASSERT ( ( . == ALIGN ( _max_align ) ), "_data16 is badly aligned" ); - . = _text_load_addr - _text_link_addr; + . = _textdata_load_addr - _textdata_link_addr; _assert = ASSERT ( ( . == ALIGN ( _max_align ) ), "_text is badly aligned" ); diff --git a/src/arch/i386/transitions/librm.S b/src/arch/i386/transitions/librm.S index 2fbffb9e..ef94ed32 100644 --- a/src/arch/i386/transitions/librm.S +++ b/src/arch/i386/transitions/librm.S @@ -357,7 +357,7 @@ prot_call: popw %gs popal popfl - ret + data32 ret /**************************************************************************** * real_call (protected-mode near call, 32-bit virtual return address)