mirror of
https://github.com/xcat2/xNBA.git
synced 2024-12-14 07:11:32 +00:00
Cut out almost all the optional code paths, drastically simplifying the
flow of control through this code. We now always add PCI and PnP headers even for ISA ROMs; there's no harm in doing so. UNDI loader is still missing.
This commit is contained in:
Michael Brown
parent
e7eca7b7cb
commit
ef37f78cbe
@ -6,412 +6,180 @@
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* table so using a noticeable amount of stack space is a no-no.
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*/
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/* Define DELAYED_INT when NO_DELAYED_INT is not defined.
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* This allows positive tests instead of tests that contain
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* double negatives, and become confusing.
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*/
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#ifndef NO_DELAYED_INT
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#define DELAYED_INT
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#endif
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/* We need some unique magic ID, if we defer startup thru the INT18H or INT19H
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* handler. This way, we can check if we have already been installed.
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*/
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#ifndef MAGIC
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#define MAGIC 0xE44C
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#endif
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/* Hook into INT18H or INT19H handler */
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#ifdef BOOT_INT18H
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#define BOOT_INT 0x18
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#else
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#define BOOT_INT 0x19
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#endif
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#define BOOT_INT_VEC BOOT_INT*4
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#define SCRATCHVEC 0x300
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/* Prefix exit codes. We store these on the stack so that we will
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* know how to return control to the BIOS when Etherboot exits.
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*/
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#define EXIT_VIA_LRET 0x0
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#define EXIT_VIA_INT_18 0x1
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#define EXIT_VIA_BOOT_INT 0x2
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.text
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.code16
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.arch i386
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.org 0
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.section ".prefix", "ax", @progbits
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_prefix:
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.word 0xAA55 /* BIOS extension signature */
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size: .byte 0 /* number of 512 byte blocks */
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/* = number of 256 word blocks */
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/* filled in by makerom program */
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jmp over /* skip over checksum */
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.byte 0 /* checksum */
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jmp legacyentry /* alternate entry point +6 */
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/* used by mknbi-rom */
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#ifdef PCI_PNP_HEADER
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mfgstr:
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.asciz "Etherboot"
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#ifdef PXE_EXPORT
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.org 0x00
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romheader:
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.word 0xAA55 /* BIOS extension signature */
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.byte _rom_size /* Size in 512-byte blocks */
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jmp init_vector /* Initialisation vector */
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.org 0x16
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.word UNDIROMID - _prefix
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#endif /* PXE_EXPORT */
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.word undiheader
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.org 0x18
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.word PCI - _prefix
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.word PnP - _prefix
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.word pciheader
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.org 0x1a
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.word pnpheader
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.size romheader, . - romheader
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PCI:
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.ascii "PCIR"
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.word 0x0000 /* vendor ID, filled in by makerom */
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.word 0x0000 /* device ID, filled in by makerom */
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.word 0x0000 /* pointer to vital product data */
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.word 0x0018 /* PCI data structure length */
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.byte 0x00 /* PCI data structure revision */
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.byte 0x02 /* Device Base Type code */
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.byte 0x00 /* Device Sub-Type code */
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.byte 0x00 /* Device Interface Type code */
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.word 0x0000 /* Image length same as offset 02h */
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.word 0x0001 /* revision level of code/data */
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.byte 0x00 /* code type */
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.byte 0x80 /* indicator (last PCI data structure) */
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.word 0x0000 /* reserved */
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pciheader:
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.ascii "PCIR" /* Signature */
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.word pci_vendor_id /* Vendor ID */
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.word pci_device_id /* Device ID */
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.word 0x0000 /* pointer to vital product data */
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.word pciheader_len /* PCI data structure length */
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.byte 0x00 /* PCI data structure revision */
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.byte 0x02 /* Device Base Type code */
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.byte 0x00 /* Device Sub-Type code */
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.byte 0x00 /* Device Interface Type code */
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.word _rom_size /* Image length same as offset 02h */
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.word 0x0001 /* revision level of code/data */
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.byte 0x00 /* code type */
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.byte 0x80 /* Flags (last PCI data structure) */
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.word 0x0000 /* reserved */
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.equ pciheader_len, . - pciheader
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.size pciheader, . - pciheader
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PnP:
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.ascii "$PnP"
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.byte 0x01 /* structure revision */
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.byte 0x02 /* length (in 16 byte increments) */
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.word 0x0000 /* offset of next header */
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.byte 0x00 /* Reserved */
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.byte 0x00 /* checksum filled by makerom */
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.long 0x00000000 /* Device identifier */
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.word mfgstr - _prefix
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.word 0x0 /* pointer to product name */
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/* filled by makerom */
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.byte 0x02 /* Device Base Type code */
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.byte 0x00 /* Device Sub-Type code */
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.byte 0x00 /* Device Interface Type code */
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.byte 0x14 /* device indicator */
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.word 0x0000 /* boot connection vector */
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.word 0x0000 /* disconnect vector */
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.word pnpentry - _prefix
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.word 0x0000 /* reserved */
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.word 0x0000 /* static resource information vector */
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#ifdef PXE_EXPORT
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UNDIROMID:
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.ascii "UNDI"
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.byte UNDIROMID_end - UNDIROMID /* length of structure */
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pnpheader:
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.ascii "$PnP" /* Signature */
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.byte 0x01 /* Structure revision */
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.byte ( pnpheader_len / 16 ) /* Length (in 16 byte increments) */
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.word 0x0000 /* Offset of next header */
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.byte 0x00 /* Reserved */
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.byte 0x00 /* Checksum */
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.long 0x00000000 /* Device identifier */
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.word mfgstr /* Manufacturer string */
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.word prodstr /* Product name */
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.byte 0x02 /* Device base type code */
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.byte 0x00 /* Device sub-type code */
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.byte 0x00 /* Device interface type code */
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.byte 0x54 /* Device indicator */
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.word 0x0000 /* Boot connection vector */
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.word 0x0000 /* Disconnect vector */
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.word exec_vector /* Boot execution vector */
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.word 0x0000 /* Reserved */
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.word 0x0000 /* Static resource information vector*/
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.equ pnpheader_len, . - pnpheader
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.size pnpheader, . - pnpheader
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mfgstr:
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.asciz "http://etherboot.org"
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.size mfgstr, . - mfgstr
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prodstr:
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.asciz "Etherboot"
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.size prodstr, . - prodstr
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undiheader:
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.ascii "UNDI" /* Signature */
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.byte undiheader_len /* Length of structure */
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.byte 0 /* Checksum */
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.byte 0 /* Structure revision */
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.byte 0,1,2 /* PXE version 2.1.0 */
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.word UNDILoader - _prefix /* Offset to loader routine */
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.word _real_mode_stack_size /* Stack segment size */
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.word _real_mode_stack_size /* Data segment size */
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.word _pxe_stack_size /* Code segment size */
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.ascii "PCIR"
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.byte 0,1,2 /* PXE version: 2.1.0 */
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.word undiloader /* Offset to loader routine */
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.word _data16_size /* Stack segment size */
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.word _data16_size /* Data segment size */
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.word _text16_size /* Code segment size */
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.equ undiheader_len, . - undiheader
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.size undiheader, . - undiheader
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/* The code segment contains our pxe_stack_t plus the PXE and
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* RM callback interfaces. We don't actually use a data
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* segment, but we put a nonzero value here to avoid confusing
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* things. 16k of stack space should be enough.
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*
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* When we claim our own memory, we fill out the data segment
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* with the address and size of the real-mode stack, so that
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* NBPs will free that area of memory for us. When the UNDI
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* loader is used to initialise us, we will never need a
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* real-mode stack because we will only ever be called via the
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* PXE API, hence our stack is already in base memory.
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*/
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.equ UNDICodeSize, _pxe_stack_size
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.equ UNDIDataSize, _real_mode_stack_size
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.equ UNDIStackSize, _real_mode_stack_size
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UNDIROMID_end:
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#endif /* PXE_EXPORT */
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#endif /* PCI_PNP_HEADER */
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/*
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* Explicitly specify DI is wrt ES to avoid problems with some BIOSes
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* Discovered by Eric Biederman
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* In addition, some BIOSes don't point DI to the string $PnP so
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* we need another #define to take care of that.
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/* Initialisation vector
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*
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* Determine whether or not this is a PnP system via a signature
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* check. If it is PnP, return to the PnP BIOS indicating that we are
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* a boot-capable device; the BIOS will call our boot execution vector
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* if it wants to boot us. If it is not PnP, hook INT 19.
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*/
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over:
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#ifdef DEBUG_ROMPREFIX
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call print_bcv
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#endif
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/* Omit this test for ISA cards anyway */
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#ifdef PCI_PNP_HEADER
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/* Accept old name too for backward compatibility */
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#if !defined(BBS_BUT_NOT_PNP_COMPLIANT) && !defined(PNP_BUT_NOT_BBS_COMPLIANT)
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cmpw $'$'+'P'*256,%es:0(%di)
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init_vector:
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pushw %si
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cmpw $'$'+'P'*256, %es:0(%di)
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jne notpnp
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cmpw $'n'+'P'*256,%es:2(%di)
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cmpw $'n'+'P'*256, %es:2(%di)
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jne notpnp
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#endif /* BBS_BUT_NOT_PNP_COMPLIANT */
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movw $0x20,%ax
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lret
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#endif /* PCI_PNP_HEADER */
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ispnp:
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movw $ispnp_message, %si
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jmp 99f
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notpnp:
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#ifdef DEBUG_ROMPREFIX
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call print_notpnp
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#endif
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#ifdef DELAYED_INT
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pushw %ax
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pushw %ds
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xorw %ax,%ax
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movw %ax,%ds /* access first 64kB segment */
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movw SCRATCHVEC+4, %ax /* check if already installed */
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cmpw $MAGIC, %ax /* check magic word */
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jz installed
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movw BOOT_INT_VEC, %ax /* hook into INT18H or INT19H */
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movw %ax, SCRATCHVEC
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movw BOOT_INT_VEC+2, %ax
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movw %ax, SCRATCHVEC+2
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movw $start_int - _prefix, %ax
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movw %ax, BOOT_INT_VEC
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movw %cs,%ax
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movw %ax, BOOT_INT_VEC+2
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movw $MAGIC, %ax /* set magic word */
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movw %ax, SCRATCHVEC+4
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#ifdef DEBUG_ROMPREFIX
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call print_installed
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#endif
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installed:
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pushw $0
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popw %ds
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popw %ax
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movw $0x20,%ax
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lret
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start_int: /* clobber magic id, so that we will */
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#ifdef DEBUG_ROMPREFIX
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call print_start_int
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#endif
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xorw %ax,%ax /* not inadvertendly end up in an */
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movw %ax,%ds /* endless loop */
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movw %ax, SCRATCHVEC+4
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movw SCRATCHVEC+2, %ax /* restore original INT19h handler */
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movw %ax, BOOT_INT_VEC+2
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movw SCRATCHVEC, %ax
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movw %ax, BOOT_INT_VEC
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pushl %eax /* padding */
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pushw $EXIT_VIA_BOOT_INT
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jmp invoke
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#endif /* DELAYED_INT */
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legacyentry:
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#ifdef DEBUG_ROMPREFIX
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call print_legacyentry
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#endif
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pushw $EXIT_VIA_LRET
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jmp invoke
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#ifdef PCI_PNP_HEADER
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pnpentry:
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#ifdef DEBUG_ROMPREFIX
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call print_bev
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#endif
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pushl %eax /* padding */
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pushw $EXIT_VIA_INT_18
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jmp invoke
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#endif /* PCI_PNP_HEADER */
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invoke:
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/* Store ROM segment and size on stack */
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pushw %ax
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pushw %ds
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pushw %cs
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movzbw %cs:(size-_prefix), %ax
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shlw $9, %ax /* 512-byte blocks */
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pushw %ax
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/* Relocate to free base memory, switch stacks */
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pushw $12 /* Preserve exit code & far ret addr */
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call prelocate
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/* We are now running in RAM */
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popw %ax /* padding */
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movw %cs, %ax
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movw %ax, %ds
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popw %ds:(_prefix_rom+2) /* ROM size */
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popw %ds:(_prefix_rom+0) /* ROM segment */
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popw %ds /* Original %ds */
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popw %ax /* Original %ax */
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pushw %ax /* 4-byte alignment */
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pushl $8 /* Preserve exit code & far ret addr */
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pushw $0 /* Set null return address */
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jmp _start
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.section ".text16", "ax", @progbits
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prefix_exit:
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popw %ax /* padding */
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popw %ax /* %ax = exit code */
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cmpw $EXIT_VIA_LRET, %ax
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jne 1f
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/* Exit via LRET */
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pushw $exec_vector
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popl ( 0x19 * 4 )
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popw %ds
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movw $notpnp_message, %si
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99:
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call print_message
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movw $0x20, %ax
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popw %si
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lret
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1: addw $4, %sp /* Strip padding */
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cmpw $EXIT_VIA_BOOT_INT, %ax
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jne 2f
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/* Exit via int BOOT_INT */
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int $BOOT_INT /* Try original vector */
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2: /* Exit via int $0x18 */
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int $0x18 /* As per BIOS Boot Spec, next dev */
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prefix_exit_end:
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.size init_vector, . - init_vector
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ispnp_message:
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.asciz "Etherboot detected PnP BIOS\r\n"
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.size ispnp_message, . - ispnp_message
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notpnp_message:
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.asciz "Etherboot detected non-PnP BIOS\r\n"
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.size notpnp_message, . - notpnp_message
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/* Boot execution vector
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*
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* Called by the PnP BIOS when it wants to boot us, or via the hooked
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* INT 19 if we detected a non-PnP BIOS.
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*/
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exec_vector:
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/* Obtain a reasonably-sized stack */
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xorw %ax, %ax
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movw %ax, %ss
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movw $0x7c00, %sp
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movw $exec_message, %si
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call print_message
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call install
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/* Jump to .text16 segment */
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pushw %ax
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pushw $1f
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lret
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.section ".text16", "awx", @progbits
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1:
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pushl $main
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pushw %cs
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call prot_call
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popl %eax /* discard */
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/* Boot next device */
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int $0x18
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.previous
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/* UNDI loader needs to be rewritten to use new mechanism */
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#if 0
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#ifdef PXE_EXPORT
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#define PXENV_UNDI_LOADER 0x104d
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.section ".prefix"
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UNDILoader:
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/* Loader API is different to the usual PXE API; there is no
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* opcode on the stack. We arrange the stack to look like a
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* normal PXE API call; this makes the Etherboot internals
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* cleaner and avoids adding an extra API type just for the
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* PXE loader.
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*/
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pushw %bx
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movw %sp, %ax /* Store original %ss:sp */
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pushw %ss
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pushw %ax
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pushl %eax /* Space for loader structure ptr */
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pushw %bp
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movw %sp, %bp
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movw 16(%bp), %ax /* Copy loader structure ptr */
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movw %ax, 2(%bp)
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movw 18(%bp), %ax
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movw %ax, 4(%bp)
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popw %bp
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pushw $PXENV_UNDI_LOADER /* PXE 'opcode' */
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pushl %eax /* dummy return address */
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/* Stack now looks like a normal PXE API call */
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/* Store ROM segment and size on stack */
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pushw %ax
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pushw %cs
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movzbw %cs:(size-_prefix), %ax
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shlw $9, %ax /* 512-byte blocks */
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pushw %ax
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/* Unpack Etherboot into temporarily claimed base memory */
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pushw $20 /* Dummy ret, PXE params, orig ss:sp */
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call prelocate
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popw %ax /* discard */
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popw %cs:(_prefix_rom+2) /* ROM size */
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popw %cs:(_prefix_rom+0) /* ROM segment */
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popw %ax /* Original %ax */
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/* Inhibit automatic deallocation of base memory */
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movl $0, %cs:_prefix_image_basemem
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/* Make PXE API call to Etherboot */
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pushl $0x201 /* PXE API version */
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/* Need to USE_INTERNAL_STACK, since we will call relocate() */
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pushl $(EB_OPCODE_PXE|EB_USE_INTERNAL_STACK) /* PXE API call type */
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call _entry
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addw $18, %sp /* discard */
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popw %bx /* Restore original %ss:sp */
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popw %ss
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movw %bx, %sp
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popw %bx
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call deprelocate
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lret $2 /* Skip our PXE 'opcode' */
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#endif /* PXE_EXPORT */
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#endif /* 0 */
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#ifdef DEBUG_ROMPREFIX
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.section ".prefix"
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print_bcv:
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pushw %si
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movw $1f-_prefix, %si
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call print_message
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popw %si
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ret
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1: .asciz "ROM detected\r\n"
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print_bev:
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pushw %si
|
||||
movw $1f-_prefix, %si
|
||||
call print_message
|
||||
popw %si
|
||||
ret
|
||||
1: .asciz "booting\r\n"
|
||||
|
||||
print_notpnp:
|
||||
pushw %si
|
||||
movw $1f-_prefix, %si
|
||||
call print_message
|
||||
popw %si
|
||||
ret
|
||||
1: .asciz ": Non-PnP BIOS detected!\r\n"
|
||||
|
||||
print_legacyentry:
|
||||
pushw %si
|
||||
movw $1f-_prefix, %si
|
||||
call print_message
|
||||
popw %si
|
||||
ret
|
||||
1: .asciz "ROM using legacy boot mechanism\r\n"
|
||||
|
||||
print_installed:
|
||||
pushw %si
|
||||
movw $1f-_prefix, %si
|
||||
call print_message
|
||||
popw %si
|
||||
ret
|
||||
1: .ascii "hooked boot via INT"
|
||||
#ifdef BOOT_INT18H
|
||||
.asciz "18\r\n"
|
||||
#else
|
||||
.asciz "19\r\n"
|
||||
#endif
|
||||
|
||||
print_start_int:
|
||||
pushw %si
|
||||
movw $1f-_prefix, %si
|
||||
call print_message
|
||||
popw %si
|
||||
ret
|
||||
1: .asciz "booting via hooked interrupt\r\n"
|
||||
exec_message:
|
||||
.asciz "Etherboot starting boot\r\n"
|
||||
.size exec_message, . - exec_message
|
||||
|
||||
/* UNDI loader
|
||||
*
|
||||
* Called by an external program to load our PXE stack.
|
||||
*/
|
||||
undiloader:
|
||||
.size undiloader, . - undiloader
|
||||
|
||||
/* Utility function: print string
|
||||
*/
|
||||
print_message:
|
||||
pushaw
|
||||
pushw %ds
|
||||
pushw %cs
|
||||
popw %ds
|
||||
pushw %si
|
||||
movw $1f-_prefix, %si
|
||||
call print_string
|
||||
popw %si
|
||||
call print_string
|
||||
popw %ds
|
||||
popaw
|
||||
ret
|
||||
1: .asciz "Etherboot "
|
||||
|
||||
print_string:
|
||||
1: lodsb
|
||||
testb %al,%al
|
||||
pushw %ax
|
||||
pushw %bx
|
||||
pushw %bp
|
||||
movw $0x0007, %bx
|
||||
1: cs lodsb
|
||||
testb %al, %al
|
||||
je 2f
|
||||
movw $0x0007, %bx /* page 0, attribute 7 (normal) */
|
||||
movb $0x0e, %ah /* write char, tty mode */
|
||||
int $0x10
|
||||
jmp 1b
|
||||
2: ret
|
||||
|
||||
#endif
|
||||
2: popw %bp
|
||||
popw %bx
|
||||
popw %ax
|
||||
ret
|
||||
.size print_message, . - print_message
|
||||
|
||||
Loading…
Reference in New Issue
Block a user