diff options
Diffstat (limited to 'gpxe/src/arch/i386/prefix/libprefix.S')
| -rw-r--r-- | gpxe/src/arch/i386/prefix/libprefix.S | 168 |
1 files changed, 141 insertions, 27 deletions
diff --git a/gpxe/src/arch/i386/prefix/libprefix.S b/gpxe/src/arch/i386/prefix/libprefix.S index ae2a491f..56ca64d9 100644 --- a/gpxe/src/arch/i386/prefix/libprefix.S +++ b/gpxe/src/arch/i386/prefix/libprefix.S @@ -199,6 +199,39 @@ print_pci_busdevfn: 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" + .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 */ + movb $' ', %al + movw $79, %cx +1: call print_character + loop 1b + /* Print CR */ + movb $'\r', %al + call print_character + /* Restore registers and return */ + popw %cx + popw %ax + ret + .size print_kill_line, . - print_kill_line + /**************************************************************************** * pm_call (real-mode near call) * @@ -308,7 +341,7 @@ pm_call: /* Switch CPU to protected mode and load up segment registers */ pushl %eax cli - lgdt PM_CALL_VAR(gdt)(%bp) + data32 lgdt PM_CALL_VAR(gdt)(%bp) movl %cr0, %eax orb $CR0_PE, %al movl %eax, %cr0 @@ -344,7 +377,7 @@ pm_call: popw %es popw %fs popw %gs - lgdt PM_CALL_VAR(pm_saved_gdt)(%bp) + data32 lgdt PM_CALL_VAR(pm_saved_gdt)(%bp) popfl movw %bp, %sp popw %bp @@ -504,31 +537,89 @@ install_block: .code16 .globl alloc_basemem alloc_basemem: + /* Preserve registers */ + pushw %fs + /* FBMS => %ax as segment address */ - movw $0x40, %ax - movw %ax, %fs + pushw $0x40 + popw %fs movw %fs:0x13, %ax shlw $6, %ax - /* .data16 segment address */ - subw $_data16_size_pgh, %ax + /* Calculate .data16 segment address */ + subw $_data16_memsz_pgh, %ax pushw %ax - /* .text16 segment address */ - subw $_text16_size_pgh, %ax + /* Calculate .text16 segment address */ + subw $_text16_memsz_pgh, %ax pushw %ax /* Update FBMS */ shrw $6, %ax movw %ax, %fs:0x13 - /* Return */ + /* Retrieve .text16 and .data16 segment addresses */ popw %ax popw %bx + + /* Restore registers and return */ + popw %fs ret .size alloc_basemem, . - alloc_basemem /**************************************************************************** + * free_basemem (real-mode near call) + * + * Free space allocated with alloc_basemem. + * + * Parameters: + * %ax : .text16 segment address + * %bx : .data16 segment address + * Returns: + * %ax : 0 if successfully freed + * Corrupts: + * none + **************************************************************************** + */ + .section ".text16" + .code16 + .globl free_basemem +free_basemem: + /* Preserve registers */ + pushw %fs + + /* Check FBMS counter */ + pushw %ax + shrw $6, %ax + pushw $0x40 + popw %fs + cmpw %ax, %fs:0x13 + popw %ax + jne 1f + + /* Check hooked interrupt count */ + cmpw $0, %cs:hooked_bios_interrupts + jne 1f + + /* OK to free memory */ + 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 %fs + ret + .size free_basemem, . - free_basemem + + .section ".text16.data" + .globl hooked_bios_interrupts +hooked_bios_interrupts: + .word 0 + .size hooked_bios_interrupts, . - hooked_bios_interrupts + +/**************************************************************************** * install (real-mode near call) * * Install all text and data segments. @@ -594,19 +685,19 @@ install_prealloc: jnz 1f movw %cs, %si shll $4, %esi -1: addl $_payload_offset, %esi +1: addl $_payload_lma, %esi /* Install .text16 and .data16 */ pushl %edi movzwl %ax, %edi shll $4, %edi - movl $_text16_size, %ecx + movl $_text16_memsz, %ecx movl %ecx, %edx call install_block /* .text16 */ movzwl %bx, %edi shll $4, %edi - movl $_data16_progbits_size, %ecx - movl $_data16_size, %edx + movl $_data16_filesz, %ecx + movl $_data16_memsz, %edx call install_block /* .data16 */ popl %edi @@ -622,8 +713,8 @@ install_prealloc: * prior to reading the E820 memory map and relocating * properly. */ - movl $_textdata_progbits_size, %ecx - movl $_textdata_size, %edx + movl $_textdata_filesz, %ecx + movl $_textdata_memsz, %edx call install_block /* Initialise librm at current location */ @@ -676,30 +767,53 @@ prot_call_vector: .size prot_call_vector, . - prot_call_vector #endif +/**************************************************************************** + * uninstall (real-mode near call) + * + * Uninstall all text and data segments. + * + * Parameters: + * %ax : .text16 segment address + * %bx : .data16 segment address + * Returns: + * none + * Corrupts: + * none + **************************************************************************** + */ + .section ".text16" + .code16 + .globl uninstall +uninstall: + call free_basemem + ret + .size uninstall, . - uninstall + + /* File split information for the compressor */ #if COMPRESS - .section ".zinfo", "a" + .section ".zinfo", "a", @progbits .ascii "COPY" - .long _prefix_load_offset - .long _prefix_progbits_size + .long _prefix_lma + .long _prefix_filesz .long _max_align .ascii "PACK" - .long _text16_load_offset - .long _text16_progbits_size + .long _text16_lma + .long _text16_filesz .long _max_align .ascii "PACK" - .long _data16_load_offset - .long _data16_progbits_size + .long _data16_lma + .long _data16_filesz .long _max_align .ascii "PACK" - .long _textdata_load_offset - .long _textdata_progbits_size + .long _textdata_lma + .long _textdata_filesz .long _max_align #else /* COMPRESS */ - .section ".zinfo", "a" + .section ".zinfo", "a", @progbits .ascii "COPY" - .long _prefix_load_offset - .long _load_size + .long _prefix_lma + .long _filesz .long _max_align #endif /* COMPRESS */ |