diff options
Diffstat (limited to 'gpxe/src/arch/i386/prefix/romprefix.S')
| -rw-r--r-- | gpxe/src/arch/i386/prefix/romprefix.S | 1079 |
1 files changed, 0 insertions, 1079 deletions
diff --git a/gpxe/src/arch/i386/prefix/romprefix.S b/gpxe/src/arch/i386/prefix/romprefix.S deleted file mode 100644 index 02e54976..00000000 --- a/gpxe/src/arch/i386/prefix/romprefix.S +++ /dev/null @@ -1,1079 +0,0 @@ -/* At entry, the processor is in 16 bit real mode and the code is being - * executed from an address it was not linked to. Code must be pic and - * 32 bit sensitive until things are fixed up. - * - * Also be very careful as the stack is at the rear end of the interrupt - * table so using a noticeable amount of stack space is a no-no. - */ - -FILE_LICENCE ( GPL2_OR_LATER ) - -#include <config/general.h> - -#define PNP_SIGNATURE ( '$' + ( 'P' << 8 ) + ( 'n' << 16 ) + ( 'P' << 24 ) ) -#define PMM_SIGNATURE ( '$' + ( 'P' << 8 ) + ( 'M' << 16 ) + ( 'M' << 24 ) ) -#define PCI_SIGNATURE ( 'P' + ( 'C' << 8 ) + ( 'I' << 16 ) + ( ' ' << 24 ) ) -#define STACK_MAGIC ( 'L' + ( 'R' << 8 ) + ( 'E' << 16 ) + ( 'T' << 24 ) ) -#define PNP_GET_BBS_VERSION 0x60 -#define PMM_ALLOCATE 0x0000 -#define PMM_DEALLOCATE 0x0002 - -/* ROM banner timeout. Based on the configurable BANNER_TIMEOUT in - * config.h, but converted to a number of (18Hz) timer ticks, and - * doubled to allow for BIOSes that switch video modes immediately - * beforehand, so rendering the message almost invisible to the user. - */ -#define ROM_BANNER_TIMEOUT ( 2 * ( 18 * BANNER_TIMEOUT ) / 10 ) - -/* We can load a ROM in two ways: have the BIOS load all of it (.rom prefix) - * or have the BIOS load a stub that loads the rest using PCI (.xrom prefix). - * The latter is not as widely supported, but allows the use of large ROMs - * on some systems with crowded option ROM space. - */ - -#ifdef LOAD_ROM_FROM_PCI -#define ROM_SIZE_VALUE _prefix_filesz_sect /* Amount to load in BIOS */ -#else -#define ROM_SIZE_VALUE 0 /* Load amount (before compr. fixup) */ -#endif - - - .text - .code16 - .arch i386 - .section ".prefix", "ax", @progbits - - .org 0x00 -romheader: - .word 0xAA55 /* BIOS extension signature */ -romheader_size: .byte ROM_SIZE_VALUE /* Size in 512-byte blocks */ - jmp init /* Initialisation vector */ -checksum: - .byte 0, 0 -real_size: - .word 0 - .org 0x16 - .word undiheader - .org 0x18 - .word pciheader - .org 0x1a - .word pnpheader - .size romheader, . - romheader - - .section ".zinfo.fixup", "a", @progbits /* Compressor fixups */ -#ifndef LOAD_ROM_FROM_PCI - .ascii "ADDB" - .long romheader_size - .long 512 - .long 0 -#endif - .ascii "ADDB" - .long real_size - .long 512 - .long 0 - .previous - -pciheader: - .ascii "PCIR" /* Signature */ - .word pci_vendor_id /* Vendor identification */ - .word pci_device_id /* Device identification */ - .word 0x0000 /* Device list pointer */ - .word pciheader_len /* PCI data structure length */ - .byte 0x03 /* PCI data structure revision */ - .byte 0x02, 0x00, 0x00 /* Class code */ -pciheader_image_length: - .word ROM_SIZE_VALUE /* Image length */ - .word 0x0001 /* Revision level */ - .byte 0x00 /* Code type */ - .byte 0x80 /* Last image indicator */ -pciheader_runtime_length: - .word ROM_SIZE_VALUE /* Maximum run-time image length */ - .word 0x0000 /* Configuration utility code header */ - .word 0x0000 /* DMTF CLP entry point */ - .equ pciheader_len, . - pciheader - .size pciheader, . - pciheader - -#ifndef LOAD_ROM_FROM_PCI - .section ".zinfo.fixup", "a", @progbits /* Compressor fixups */ - .ascii "ADDW" - .long pciheader_image_length - .long 512 - .long 0 - .ascii "ADDW" - .long pciheader_runtime_length - .long 512 - .long 0 - .previous -#endif - -pnpheader: - .ascii "$PnP" /* Signature */ - .byte 0x01 /* Structure revision */ - .byte ( pnpheader_len / 16 ) /* Length (in 16 byte increments) */ - .word 0x0000 /* Offset of next header */ - .byte 0x00 /* Reserved */ - .byte 0x00 /* Checksum */ - .long 0x00000000 /* Device identifier */ - .word mfgstr /* Manufacturer string */ - .word prodstr /* Product name */ - .byte 0x02 /* Device base type code */ - .byte 0x00 /* Device sub-type code */ - .byte 0x00 /* Device interface type code */ - .byte 0xf4 /* Device indicator */ - .word 0x0000 /* Boot connection vector */ - .word 0x0000 /* Disconnect vector */ - .word bev_entry /* Boot execution vector */ - .word 0x0000 /* Reserved */ - .word 0x0000 /* Static resource information vector*/ - .equ pnpheader_len, . - pnpheader - .size pnpheader, . - pnpheader - -/* Manufacturer string */ -mfgstr: - .asciz "http://etherboot.org" - .size mfgstr, . - mfgstr - -/* Product string - * - * Defaults to PRODUCT_SHORT_NAME. If the ROM image is writable at - * initialisation time, it will be filled in to include the PCI - * bus:dev.fn number of the card as well. - */ -prodstr: - .ascii PRODUCT_SHORT_NAME -prodstr_separator: - .byte 0 - .ascii "(PCI " -prodstr_pci_id: - .asciz "xx:xx.x)" /* Filled in by init code */ - .size prodstr, . - prodstr - - .globl undiheader - .weak undiloader -undiheader: - .ascii "UNDI" /* Signature */ - .byte undiheader_len /* Length of structure */ - .byte 0 /* Checksum */ - .byte 0 /* Structure revision */ - .byte 0,1,2 /* PXE version: 2.1.0 */ - .word undiloader /* Offset to loader routine */ - .word _data16_memsz /* Stack segment size */ - .word _data16_memsz /* Data segment size */ - .word _text16_memsz /* Code segment size */ - .ascii "PCIR" /* Bus type */ - .equ undiheader_len, . - undiheader - .size undiheader, . - undiheader - -/* Initialisation (called once during POST) - * - * Determine whether or not this is a PnP system via a signature - * check. If it is PnP, return to the PnP BIOS indicating that we are - * a boot-capable device; the BIOS will call our boot execution vector - * if it wants to boot us. If it is not PnP, hook INT 19. - */ -init: - /* Preserve registers, clear direction flag, set %ds=%cs */ - pushaw - pushw %ds - pushw %es - pushw %fs - pushw %gs - cld - pushw %cs - popw %ds - - /* Shuffle some registers around. We need %di available for - * the print_xxx functions, and in a register that's - * addressable from %es, so shuffle as follows: - * - * %di (pointer to PnP structure) => %bx - * %bx (runtime segment address, for PCI 3.0) => %gs - */ - movw %bx, %gs - movw %di, %bx - - /* Print message as early as possible */ - movw $init_message, %si - xorw %di, %di - call print_message - call print_pci_busdevfn - -#ifdef LOAD_ROM_FROM_PCI - /* Save PCI bus:dev.fn for later use */ - movw %ax, pci_busdevfn -#endif - - /* Fill in product name string, if possible */ - movw $prodstr_pci_id, %di - call print_pci_busdevfn - movb $( ' ' ), prodstr_separator - - /* Print segment address */ - movb $( ' ' ), %al - xorw %di, %di - call print_character - movw %cs, %ax - call print_hex_word - - /* Check for PCI BIOS version */ - pushl %ebx - pushl %edx - pushl %edi - stc - movw $0xb101, %ax - int $0x1a - jc no_pci3 - cmpl $PCI_SIGNATURE, %edx - jne no_pci3 - testb %ah, %ah - jnz no_pci3 -#ifdef LOAD_ROM_FROM_PCI - incb pcibios_present -#endif - movw $init_message_pci, %si - xorw %di, %di - call print_message - movb %bh, %al - call print_hex_nibble - movb $( '.' ), %al - call print_character - movb %bl, %al - call print_hex_byte - cmpb $3, %bh - jb no_pci3 - /* PCI >=3.0: leave %gs as-is if sane */ - movw %gs, %ax - cmpw $0xa000, %ax /* Insane if %gs < 0xa000 */ - jb pci3_insane - movw %cs, %bx /* Sane if %cs == %gs */ - cmpw %bx, %ax - je 1f - movzbw romheader_size, %cx /* Sane if %cs+len <= %gs */ - shlw $5, %cx - addw %cx, %bx - cmpw %bx, %ax - jae 1f - movw %cs, %bx /* Sane if %gs+len <= %cs */ - addw %cx, %ax - cmpw %bx, %ax - jbe 1f -pci3_insane: /* PCI 3.0 with insane %gs value: print error and ignore %gs */ - movb $( '!' ), %al - call print_character - movw %gs, %ax - call print_hex_word -no_pci3: - /* PCI <3.0: set %gs (runtime segment) = %cs (init-time segment) */ - pushw %cs - popw %gs -1: popl %edi - popl %edx - popl %ebx - - /* Check for PnP BIOS. Although %es:di should point to the - * PnP BIOS signature on entry, some BIOSes fail to do this. - */ - movw $( 0xf000 - 1 ), %bx -pnp_scan: - incw %bx - jz no_pnp - movw %bx, %es - cmpl $PNP_SIGNATURE, %es:0 - jne pnp_scan - xorw %dx, %dx - xorw %si, %si - movzbw %es:5, %cx -1: es lodsb - addb %al, %dl - loop 1b - jnz pnp_scan - /* Is PnP: print PnP message */ - movw $init_message_pnp, %si - xorw %di, %di - call print_message - /* Check for BBS */ - pushw %es:0x1b /* Real-mode data segment */ - pushw %ds /* &(bbs_version) */ - pushw $bbs_version - pushw $PNP_GET_BBS_VERSION - lcall *%es:0xd - addw $8, %sp - testw %ax, %ax - je got_bbs -no_pnp: /* Not PnP-compliant - therefore cannot be BBS-compliant */ -no_bbs: /* Not BBS-compliant - must hook INT 19 */ - movw $init_message_int19, %si - xorw %di, %di - call print_message - xorw %ax, %ax - movw %ax, %es - pushl %es:( 0x19 * 4 ) - popl orig_int19 - pushw %gs /* %gs contains runtime %cs */ - pushw $int19_entry - popl %es:( 0x19 * 4 ) - jmp bbs_done -got_bbs: /* BBS compliant - no need to hook INT 19 */ - movw $init_message_bbs, %si - xorw %di, %di - call print_message -bbs_done: - - /* Check for PMM */ - movw $( 0xe000 - 1 ), %bx -pmm_scan: - incw %bx - jz no_pmm - movw %bx, %es - cmpl $PMM_SIGNATURE, %es:0 - jne pmm_scan - xorw %dx, %dx - xorw %si, %si - movzbw %es:5, %cx -1: es lodsb - addb %al, %dl - loop 1b - jnz pmm_scan - /* PMM found: print PMM message */ - movw $init_message_pmm, %si - xorw %di, %di - call print_message - /* We have PMM and so a 1kB stack: preserve upper register halves */ - pushal - /* Calculate required allocation size in %esi */ - movzwl real_size, %eax - shll $9, %eax - addl $_textdata_memsz, %eax - orw $0xffff, %ax /* Ensure allocation size is at least 64kB */ - bsrl %eax, %ecx - subw $15, %cx /* Round up and convert to 64kB count */ - movw $1, %si - shlw %cl, %si -pmm_loop: - /* Try to allocate block via PMM */ - pushw $0x0006 /* Aligned, extended memory */ - pushl $0xffffffff /* No handle */ - movzwl %si, %eax - shll $12, %eax - pushl %eax /* Allocation size in paragraphs */ - pushw $PMM_ALLOCATE - lcall *%es:7 - addw $12, %sp - /* Abort if allocation fails */ - testw %dx, %dx /* %ax==0 even on success, since align>=64kB */ - jz pmm_fail - /* If block has A20==1, free block and try again with twice - * the allocation size (and hence alignment). - */ - testw $0x0010, %dx - jz got_pmm - pushw %dx - pushw $0 - pushw $PMM_DEALLOCATE - lcall *%es:7 - addw $6, %sp - addw %si, %si - jmp pmm_loop -got_pmm: /* PMM allocation succeeded */ - movw %dx, ( image_source + 2 ) - movw %dx, %ax - xorw %di, %di - call print_hex_word - movb $( '@' ), %al - call print_character - movw %si, %ax - call print_hex_byte -pmm_copy: - /* Copy ROM to PMM block */ - xorw %ax, %ax - movw %ax, %es - movl image_source, %edi - xorl %esi, %esi - movzbl romheader_size, %ecx - shll $9, %ecx - addr32 rep movsb /* PMM presence implies flat real mode */ - movl %edi, decompress_to - /* Shrink ROM */ - movb $_prefix_memsz_sect, romheader_size -#if defined(SHRINK_WITHOUT_PMM) || defined(LOAD_ROM_FROM_PCI) - jmp pmm_done -pmm_fail: - /* Print marker and copy ourselves to high memory */ - movl $HIGHMEM_LOADPOINT, image_source - xorw %di, %di - movb $( '!' ), %al - call print_character - jmp pmm_copy -pmm_done: -#else -pmm_fail: -#endif - /* Restore upper register halves */ - popal -#if defined(LOAD_ROM_FROM_PCI) - call load_from_pci - jc load_err - jmp load_ok -no_pmm: - /* Cannot continue without PMM - print error message */ - xorw %di, %di - movw $init_message_no_pmm, %si - call print_message -load_err: - /* Wait for five seconds to let user see message */ - movw $90, %cx -1: call wait_for_tick - loop 1b - /* Mark environment as invalid and return */ - movl $0, decompress_to - jmp out - -load_ok: -#else -no_pmm: -#endif - /* Update checksum */ - xorw %bx, %bx - xorw %si, %si - movzbw romheader_size, %cx - shlw $9, %cx -1: lodsb - addb %al, %bl - loop 1b - subb %bl, checksum - - /* Copy self to option ROM space. Required for PCI3.0, which - * loads us to a temporary location in low memory. Will be a - * no-op for lower PCI versions. - */ - movb $( ' ' ), %al - xorw %di, %di - call print_character - movw %gs, %ax - call print_hex_word - movzbw romheader_size, %cx - shlw $9, %cx - movw %ax, %es - xorw %si, %si - xorw %di, %di - cs rep movsb - - /* Prompt for POST-time shell */ - movw $init_message_prompt, %si - xorw %di, %di - call print_message - movw $prodstr, %si - call print_message - movw $init_message_dots, %si - call print_message - /* Wait for Ctrl-B */ - movw $0xff02, %bx - call wait_for_key - /* Clear prompt */ - pushf - xorw %di, %di - call print_kill_line - movw $init_message_done, %si - call print_message - popf - jnz out - /* Ctrl-B was pressed: invoke gPXE. The keypress will be - * picked up by the initial shell prompt, and we will drop - * into a shell. - */ - pushw %cs - call exec -out: - /* Restore registers */ - popw %gs - popw %fs - popw %es - popw %ds - popaw - - /* Indicate boot capability to PnP BIOS, if present */ - movw $0x20, %ax - lret - .size init, . - init - -/* - * Note to hardware vendors: - * - * If you wish to brand this boot ROM, please do so by defining the - * strings PRODUCT_NAME and PRODUCT_SHORT_NAME in config/general.h. - * - * While nothing in the GPL prevents you from removing all references - * to gPXE or http://etherboot.org, we prefer you not to do so. - * - * If you have an OEM-mandated branding requirement that cannot be - * satisfied simply by defining PRODUCT_NAME and PRODUCT_SHORT_NAME, - * please contact us. - * - * [ Including an ASCII NUL in PRODUCT_NAME is considered to be - * bypassing the spirit of this request! ] - */ -init_message: - .ascii "\n" - .ascii PRODUCT_NAME - .ascii "\n" - .asciz "gPXE (http://etherboot.org) - " - .size init_message, . - init_message -init_message_pci: - .asciz " PCI" - .size init_message_pci, . - init_message_pci -init_message_pnp: - .asciz " PnP" - .size init_message_pnp, . - init_message_pnp -init_message_bbs: - .asciz " BBS" - .size init_message_bbs, . - init_message_bbs -init_message_pmm: - .asciz " PMM" - .size init_message_pmm, . - init_message_pmm -#ifdef LOAD_ROM_FROM_PCI -init_message_no_pmm: - .asciz "\nPMM required but not present!\n" - .size init_message_no_pmm, . - init_message_no_pmm -#endif -init_message_int19: - .asciz " INT19" - .size init_message_int19, . - init_message_int19 -init_message_prompt: - .asciz "\nPress Ctrl-B to configure " - .size init_message_prompt, . - init_message_prompt -init_message_dots: - .asciz "..." - .size init_message_dots, . - init_message_dots -init_message_done: - .asciz "\n\n" - .size init_message_done, . - init_message_done - -/* ROM image location - * - * May be either within option ROM space, or within PMM-allocated block. - */ - .globl image_source -image_source: - .long 0 - .size image_source, . - image_source - -/* Temporary decompression area - * - * May be either at HIGHMEM_LOADPOINT, or within PMM-allocated block. - * If a PCI ROM load fails, this will be set to zero. - */ - .globl decompress_to -decompress_to: - .long HIGHMEM_LOADPOINT - .size decompress_to, . - decompress_to - -#ifdef LOAD_ROM_FROM_PCI - -/* Set if the PCI BIOS is present, even <3.0 */ -pcibios_present: - .byte 0 - .byte 0 /* for alignment */ - .size pcibios_present, . - pcibios_present - -/* PCI bus:device.function word - * - * Filled in by init in the .xrom case, so the remainder of the ROM - * can be located. - */ -pci_busdevfn: - .word 0 - .size pci_busdevfn, . - pci_busdevfn - -#endif - -/* BBS version - * - * Filled in by BBS BIOS. We ignore the value. - */ -bbs_version: - .word 0 - .size bbs_version, . - bbs_version - -/* Boot Execution Vector entry point - * - * Called by the PnP BIOS when it wants to boot us. - */ -bev_entry: - pushw %cs - call exec - lret - .size bev_entry, . - bev_entry - - -#ifdef LOAD_ROM_FROM_PCI - -#define PCI_ROM_ADDRESS 0x30 /* Bits 31:11 address, 10:1 reserved */ -#define PCI_ROM_ADDRESS_ENABLE 0x00000001 -#define PCI_ROM_ADDRESS_MASK 0xfffff800 - -#define PCIBIOS_READ_WORD 0xb109 -#define PCIBIOS_READ_DWORD 0xb10a -#define PCIBIOS_WRITE_WORD 0xb10c -#define PCIBIOS_WRITE_DWORD 0xb10d - -/* Determine size of PCI BAR - * - * %bx : PCI bus:dev.fn to probe - * %di : Address of BAR to find size of - * %edx : Mask of address bits within BAR - * - * %ecx : Size for a memory resource, - * 1 for an I/O resource (bit 0 set). - * CF : Set on error or nonexistent device (all-ones read) - * - * All other registers saved. - */ -pci_bar_size: - /* Save registers */ - pushw %ax - pushl %esi - pushl %edx - - /* Read current BAR value */ - movw $PCIBIOS_READ_DWORD, %ax - int $0x1a - - /* Check for device existence and save it */ - testb $1, %cl /* I/O bit? */ - jz 1f - andl $1, %ecx /* If so, exit with %ecx = 1 */ - jmp 99f -1: notl %ecx - testl %ecx, %ecx /* Set ZF iff %ecx was all-ones */ - notl %ecx - jnz 1f - stc /* All ones - exit with CF set */ - jmp 99f -1: movl %ecx, %esi /* Save in %esi */ - - /* Write all ones to BAR */ - movl %edx, %ecx - movw $PCIBIOS_WRITE_DWORD, %ax - int $0x1a - - /* Read back BAR */ - movw $PCIBIOS_READ_DWORD, %ax - int $0x1a - - /* Find decode size from least set bit in mask BAR */ - bsfl %ecx, %ecx /* Find least set bit, log2(decode size) */ - jz 1f /* Mask BAR should not be zero */ - xorl %edx, %edx - incl %edx - shll %cl, %edx /* %edx = decode size */ - jmp 2f -1: xorl %edx, %edx /* Return zero size for mask BAR zero */ - - /* Restore old BAR value */ -2: movl %esi, %ecx - movw $PCIBIOS_WRITE_DWORD, %ax - int $0x1a - - movl %edx, %ecx /* Return size in %ecx */ - - /* Restore registers and return */ -99: popl %edx - popl %esi - popw %ax - ret - - .size pci_bar_size, . - pci_bar_size - -/* PCI ROM loader - * - * Called from init in the .xrom case to load the non-prefix code - * using the PCI ROM BAR. - * - * Returns with carry flag set on error. All registers saved. - */ -load_from_pci: - /* - * Use PCI BIOS access to config space. The calls take - * - * %ah : 0xb1 %al : function - * %bx : bus/dev/fn - * %di : config space address - * %ecx : value to write (for writes) - * - * %ecx : value read (for reads) - * %ah : return code - * CF : error indication - * - * All registers not used for return are preserved. - */ - - /* Save registers and set up %es for big real mode */ - pushal - pushw %es - xorw %ax, %ax - movw %ax, %es - - /* Check PCI BIOS presence */ - cmpb $0, pcibios_present - jz err_pcibios - - /* Load existing PCI ROM BAR */ - movw $PCIBIOS_READ_DWORD, %ax - movw pci_busdevfn, %bx - movw $PCI_ROM_ADDRESS, %di - int $0x1a - - /* Maybe it's already enabled? */ - testb $PCI_ROM_ADDRESS_ENABLE, %cl - jz 1f - movb $1, %dl /* Flag indicating no deinit required */ - movl %ecx, %ebp - jmp check_rom - - /* Determine PCI BAR decode size */ -1: movl $PCI_ROM_ADDRESS_MASK, %edx - call pci_bar_size /* Returns decode size in %ecx */ - jc err_size_insane /* CF => no ROM BAR, %ecx == ffffffff */ - - /* Check sanity of decode size */ - xorl %eax, %eax - movw real_size, %ax - shll $9, %eax /* %eax = ROM size */ - cmpl %ecx, %eax - ja err_size_insane /* Insane if decode size < ROM size */ - cmpl $0x100000, %ecx - jae err_size_insane /* Insane if decode size >= 1MB */ - - /* Find a place to map the BAR - * In theory we should examine e820 and all PCI BARs to find a - * free region. However, we run at POST when e820 may not be - * available, and memory reads of an unmapped location are - * de facto standardized to return all-ones. Thus, we can get - * away with searching high memory (0xf0000000 and up) on - * multiples of the ROM BAR decode size for a sufficiently - * large all-ones region. - */ - movl %ecx, %edx /* Save ROM BAR size in %edx */ - movl $0xf0000000, %ebp - xorl %eax, %eax - notl %eax /* %eax = all ones */ -bar_search: - movl %ebp, %edi - movl %edx, %ecx - shrl $2, %ecx - addr32 repe scasl /* Scan %es:edi for anything not all-ones */ - jz bar_found - addl %edx, %ebp - testl $0x80000000, %ebp - jz err_no_bar - jmp bar_search - -bar_found: - movl %edi, %ebp - /* Save current BAR value on stack to restore later */ - movw $PCIBIOS_READ_DWORD, %ax - movw $PCI_ROM_ADDRESS, %di - int $0x1a - pushl %ecx - - /* Map the ROM */ - movw $PCIBIOS_WRITE_DWORD, %ax - movl %ebp, %ecx - orb $PCI_ROM_ADDRESS_ENABLE, %cl - int $0x1a - - xorb %dl, %dl /* %dl = 0 : ROM was not already mapped */ -check_rom: - /* Check and copy ROM - enter with %dl set to skip unmapping, - * %ebp set to mapped ROM BAR address. - * We check up to prodstr_separator for equality, since anything past - * that may have been modified. Since our check includes the checksum - * byte over the whole ROM stub, that should be sufficient. - */ - xorb %dh, %dh /* %dh = 0 : ROM did not fail integrity check */ - - /* Verify ROM integrity */ - xorl %esi, %esi - movl %ebp, %edi - movl $prodstr_separator, %ecx - addr32 repe cmpsb - jz copy_rom - incb %dh /* ROM failed integrity check */ - movl %ecx, %ebp /* Save number of bytes left */ - jmp skip_load - -copy_rom: - /* Print BAR address and indicate whether we mapped it ourselves */ - movb $( ' ' ), %al - xorw %di, %di - call print_character - movl %ebp, %eax - call print_hex_dword - movb $( '-' ), %al /* '-' for self-mapped */ - subb %dl, %al - subb %dl, %al /* '+' = '-' - 2 for BIOS-mapped */ - call print_character - - /* Copy ROM at %ebp to PMM or highmem block */ - movl %ebp, %esi - movl image_source, %edi - movzwl real_size, %ecx - shll $9, %ecx - addr32 es rep movsb - movl %edi, decompress_to -skip_load: - testb %dl, %dl /* Was ROM already mapped? */ - jnz skip_unmap - - /* Unmap the ROM by restoring old ROM BAR */ - movw $PCIBIOS_WRITE_DWORD, %ax - movw $PCI_ROM_ADDRESS, %di - popl %ecx - int $0x1a - -skip_unmap: - /* Error handling */ - testb %dh, %dh - jnz err_rom_invalid - clc - jmp 99f - -err_pcibios: /* No PCI BIOS available */ - movw $load_message_no_pcibios, %si - xorl %eax, %eax /* "error code" is zero */ - jmp 1f -err_size_insane: /* BAR has size (%ecx) that is insane */ - movw $load_message_size_insane, %si - movl %ecx, %eax - jmp 1f -err_no_bar: /* No space of sufficient size (%edx) found */ - movw $load_message_no_bar, %si - movl %edx, %eax - jmp 1f -err_rom_invalid: /* Loaded ROM does not match (%ebp bytes left) */ - movw $load_message_rom_invalid, %si - movzbl romheader_size, %eax - shll $9, %eax - subl %ebp, %eax - decl %eax /* %eax is now byte index of failure */ - -1: /* Error handler - print message at %si and dword in %eax */ - xorw %di, %di - call print_message - call print_hex_dword - stc -99: popw %es - popal - ret - - .size load_from_pci, . - load_from_pci - -load_message_no_pcibios: - .asciz "\nNo PCI BIOS found! " - .size load_message_no_pcibios, . - load_message_no_pcibios - -load_message_size_insane: - .asciz "\nROM resource has invalid size " - .size load_message_size_insane, . - load_message_size_insane - -load_message_no_bar: - .asciz "\nNo memory hole of sufficient size " - .size load_message_no_bar, . - load_message_no_bar - -load_message_rom_invalid: - .asciz "\nLoaded ROM is invalid at " - .size load_message_rom_invalid, . - load_message_rom_invalid - -#endif /* LOAD_ROM_FROM_PCI */ - - -/* INT19 entry point - * - * Called via the hooked INT 19 if we detected a non-PnP BIOS. We - * attempt to return via the original INT 19 vector (if we were able - * to store it). - */ -int19_entry: - pushw %cs - popw %ds - /* Prompt user to press B to boot */ - movw $int19_message_prompt, %si - xorw %di, %di - call print_message - movw $prodstr, %si - call print_message - movw $int19_message_dots, %si - call print_message - movw $0xdf4e, %bx - call wait_for_key - pushf - xorw %di, %di - call print_kill_line - movw $int19_message_done, %si - call print_message - popf - jz 1f - /* Leave keypress in buffer and start gPXE. The keypress will - * cause the usual initial Ctrl-B prompt to be skipped. - */ - pushw %cs - call exec -1: /* Try to call original INT 19 vector */ - movl %cs:orig_int19, %eax - testl %eax, %eax - je 2f - ljmp *%cs:orig_int19 -2: /* No chained vector: issue INT 18 as a last resort */ - int $0x18 - .size int19_entry, . - int19_entry -orig_int19: - .long 0 - .size orig_int19, . - orig_int19 - -int19_message_prompt: - .asciz "Press N to skip booting from " - .size int19_message_prompt, . - int19_message_prompt -int19_message_dots: - .asciz "..." - .size int19_message_dots, . - int19_message_dots -int19_message_done: - .asciz "\n\n" - .size int19_message_done, . - int19_message_done - -/* Execute as a boot device - * - */ -exec: /* Set %ds = %cs */ - pushw %cs - popw %ds - -#ifdef LOAD_ROM_FROM_PCI - /* Don't execute if load was invalid */ - cmpl $0, decompress_to - jne 1f - lret -1: -#endif - - /* Print message as soon as possible */ - movw $prodstr, %si - xorw %di, %di - call print_message - movw $exec_message, %si - call print_message - - /* Store magic word on BIOS stack and remember BIOS %ss:sp */ - pushl $STACK_MAGIC - movw %ss, %dx - movw %sp, %bp - - /* Obtain a reasonably-sized temporary stack */ - xorw %ax, %ax - movw %ax, %ss - movw $0x7c00, %sp - - /* Install gPXE */ - movl image_source, %esi - movl decompress_to, %edi - call alloc_basemem - call install_prealloc - - /* Set up real-mode stack */ - movw %bx, %ss - movw $_estack16, %sp - - /* Jump to .text16 segment */ - pushw %ax - pushw $1f - lret - .section ".text16", "awx", @progbits -1: /* Call main() */ - pushl $main - pushw %cs - call prot_call - popl %ecx /* discard */ - - /* Uninstall gPXE */ - call uninstall - - /* Restore BIOS stack */ - movw %dx, %ss - movw %bp, %sp - - /* Check magic word on BIOS stack */ - popl %eax - cmpl $STACK_MAGIC, %eax - jne 1f - /* BIOS stack OK: return to caller */ - lret -1: /* BIOS stack corrupt: use INT 18 */ - int $0x18 - .previous - -exec_message: - .asciz " starting execution\n" - .size exec_message, . - exec_message - -/* Wait for key press specified by %bl (masked by %bh) - * - * Used by init and INT19 code when prompting user. If the specified - * key is pressed, it is left in the keyboard buffer. - * - * Returns with ZF set iff specified key is pressed. - */ -wait_for_key: - /* Preserve registers */ - pushw %cx - pushw %ax -1: /* Empty the keyboard buffer before waiting for input */ - movb $0x01, %ah - int $0x16 - jz 2f - xorw %ax, %ax - int $0x16 - jmp 1b -2: /* Wait for a key press */ - movw $ROM_BANNER_TIMEOUT, %cx -3: decw %cx - js 99f /* Exit with ZF clear */ - /* Wait for timer tick to be updated */ - call wait_for_tick - /* Check to see if a key was pressed */ - movb $0x01, %ah - int $0x16 - jz 3b - /* Check to see if key was the specified key */ - andb %bh, %al - cmpb %al, %bl - je 99f /* Exit with ZF set */ - /* Not the specified key: remove from buffer and stop waiting */ - pushfw - xorw %ax, %ax - int $0x16 - popfw /* Exit with ZF clear */ -99: /* Restore registers and return */ - popw %ax - popw %cx - ret - .size wait_for_key, . - wait_for_key - -/* Wait for timer tick - * - * Used by wait_for_key - */ -wait_for_tick: - pushl %eax - pushw %fs - movw $0x40, %ax - movw %ax, %fs - movl %fs:(0x6c), %eax -1: pushf - sti - hlt - popf - cmpl %fs:(0x6c), %eax - je 1b - popw %fs - popl %eax - ret - .size wait_for_tick, . - wait_for_tick |