mirror of
https://github.com/ipxe/ipxe
synced 2026-02-28 03:11:18 +03:00
698f86f25a
mechanism has changed anyway, and so must be rewritten, but at least doing this makes the output of "make symcheck" more legible.
418 lines
10 KiB
ArmAsm
418 lines
10 KiB
ArmAsm
/* 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.
|
|
*/
|
|
|
|
/* Define DELAYED_INT when NO_DELAYED_INT is not defined.
|
|
* This allows positive tests instead of tests that contain
|
|
* double negatives, and become confusing.
|
|
*/
|
|
#ifndef NO_DELAYED_INT
|
|
#define DELAYED_INT
|
|
#endif
|
|
|
|
/* We need some unique magic ID, if we defer startup thru the INT18H or INT19H
|
|
* handler. This way, we can check if we have already been installed.
|
|
*/
|
|
#ifndef MAGIC
|
|
#define MAGIC 0xE44C
|
|
#endif
|
|
|
|
/* Hook into INT18H or INT19H handler */
|
|
#ifdef BOOT_INT18H
|
|
#define BOOT_INT 0x18
|
|
#else
|
|
#define BOOT_INT 0x19
|
|
#endif
|
|
|
|
#define BOOT_INT_VEC BOOT_INT*4
|
|
#define SCRATCHVEC 0x300
|
|
|
|
/* Prefix exit codes. We store these on the stack so that we will
|
|
* know how to return control to the BIOS when Etherboot exits.
|
|
*/
|
|
#define EXIT_VIA_LRET 0x0
|
|
#define EXIT_VIA_INT_18 0x1
|
|
#define EXIT_VIA_BOOT_INT 0x2
|
|
|
|
.text
|
|
.code16
|
|
.arch i386
|
|
.org 0
|
|
.section ".prefix", "ax", @progbits
|
|
_prefix:
|
|
.word 0xAA55 /* BIOS extension signature */
|
|
size: .byte 0 /* number of 512 byte blocks */
|
|
/* = number of 256 word blocks */
|
|
/* filled in by makerom program */
|
|
jmp over /* skip over checksum */
|
|
.byte 0 /* checksum */
|
|
jmp legacyentry /* alternate entry point +6 */
|
|
/* used by mknbi-rom */
|
|
|
|
#ifdef PCI_PNP_HEADER
|
|
mfgstr:
|
|
.asciz "Etherboot"
|
|
|
|
#ifdef PXE_EXPORT
|
|
.org 0x16
|
|
.word UNDIROMID - _prefix
|
|
#endif /* PXE_EXPORT */
|
|
|
|
.org 0x18
|
|
.word PCI - _prefix
|
|
.word PnP - _prefix
|
|
|
|
PCI:
|
|
.ascii "PCIR"
|
|
.word 0x0000 /* vendor ID, filled in by makerom */
|
|
.word 0x0000 /* device ID, filled in by makerom */
|
|
.word 0x0000 /* pointer to vital product data */
|
|
.word 0x0018 /* PCI data structure length */
|
|
.byte 0x00 /* PCI data structure revision */
|
|
.byte 0x02 /* Device Base Type code */
|
|
.byte 0x00 /* Device Sub-Type code */
|
|
.byte 0x00 /* Device Interface Type code */
|
|
.word 0x0000 /* Image length same as offset 02h */
|
|
.word 0x0001 /* revision level of code/data */
|
|
.byte 0x00 /* code type */
|
|
.byte 0x80 /* indicator (last PCI data structure) */
|
|
.word 0x0000 /* reserved */
|
|
|
|
PnP:
|
|
.ascii "$PnP"
|
|
.byte 0x01 /* structure revision */
|
|
.byte 0x02 /* length (in 16 byte increments) */
|
|
.word 0x0000 /* offset of next header */
|
|
.byte 0x00 /* Reserved */
|
|
.byte 0x00 /* checksum filled by makerom */
|
|
.long 0x00000000 /* Device identifier */
|
|
.word mfgstr - _prefix
|
|
.word 0x0 /* pointer to product name */
|
|
/* filled by makerom */
|
|
.byte 0x02 /* Device Base Type code */
|
|
.byte 0x00 /* Device Sub-Type code */
|
|
.byte 0x00 /* Device Interface Type code */
|
|
.byte 0x14 /* device indicator */
|
|
.word 0x0000 /* boot connection vector */
|
|
.word 0x0000 /* disconnect vector */
|
|
.word pnpentry - _prefix
|
|
.word 0x0000 /* reserved */
|
|
.word 0x0000 /* static resource information vector */
|
|
#ifdef PXE_EXPORT
|
|
UNDIROMID:
|
|
.ascii "UNDI"
|
|
.byte UNDIROMID_end - UNDIROMID /* length of structure */
|
|
.byte 0 /* Checksum */
|
|
.byte 0 /* Structure revision */
|
|
.byte 0,1,2 /* PXE version 2.1.0 */
|
|
.word UNDILoader - _prefix /* Offset to loader routine */
|
|
.word UNDIStackSize /* Stack segment size */
|
|
.word UNDIDataSize /* Data segment size */
|
|
.word UNDICodeSize /* Code segment size */
|
|
.ascii "PCIR"
|
|
|
|
/* The code segment contains our pxe_stack_t plus the PXE and
|
|
* RM callback interfaces. We don't actually use a data
|
|
* segment, but we put a nonzero value here to avoid confusing
|
|
* things. 16k of stack space should be enough.
|
|
*
|
|
* When we claim our own memory, we fill out the data segment
|
|
* with the address and size of the real-mode stack, so that
|
|
* NBPs will free that area of memory for us. When the UNDI
|
|
* loader is used to initialise us, we will never need a
|
|
* real-mode stack because we will only ever be called via the
|
|
* PXE API, hence our stack is already in base memory.
|
|
*/
|
|
.equ UNDICodeSize, _pxe_stack_size
|
|
.equ UNDIDataSize, _real_mode_stack_size
|
|
.equ UNDIStackSize, _real_mode_stack_size
|
|
UNDIROMID_end:
|
|
#endif /* PXE_EXPORT */
|
|
|
|
#endif /* PCI_PNP_HEADER */
|
|
|
|
/*
|
|
* Explicitly specify DI is wrt ES to avoid problems with some BIOSes
|
|
* Discovered by Eric Biederman
|
|
* In addition, some BIOSes don't point DI to the string $PnP so
|
|
* we need another #define to take care of that.
|
|
*/
|
|
over:
|
|
#ifdef DEBUG_ROMPREFIX
|
|
call print_bcv
|
|
#endif
|
|
/* Omit this test for ISA cards anyway */
|
|
#ifdef PCI_PNP_HEADER
|
|
/* Accept old name too for backward compatibility */
|
|
#if !defined(BBS_BUT_NOT_PNP_COMPLIANT) && !defined(PNP_BUT_NOT_BBS_COMPLIANT)
|
|
cmpw $'$'+'P'*256,%es:0(%di)
|
|
jne notpnp
|
|
cmpw $'n'+'P'*256,%es:2(%di)
|
|
jne notpnp
|
|
#endif /* BBS_BUT_NOT_PNP_COMPLIANT */
|
|
movw $0x20,%ax
|
|
lret
|
|
#endif /* PCI_PNP_HEADER */
|
|
notpnp:
|
|
#ifdef DEBUG_ROMPREFIX
|
|
call print_notpnp
|
|
#endif
|
|
#ifdef DELAYED_INT
|
|
pushw %ax
|
|
pushw %ds
|
|
xorw %ax,%ax
|
|
movw %ax,%ds /* access first 64kB segment */
|
|
movw SCRATCHVEC+4, %ax /* check if already installed */
|
|
cmpw $MAGIC, %ax /* check magic word */
|
|
jz installed
|
|
movw BOOT_INT_VEC, %ax /* hook into INT18H or INT19H */
|
|
movw %ax, SCRATCHVEC
|
|
movw BOOT_INT_VEC+2, %ax
|
|
movw %ax, SCRATCHVEC+2
|
|
movw $start_int - _prefix, %ax
|
|
movw %ax, BOOT_INT_VEC
|
|
movw %cs,%ax
|
|
movw %ax, BOOT_INT_VEC+2
|
|
movw $MAGIC, %ax /* set magic word */
|
|
movw %ax, SCRATCHVEC+4
|
|
#ifdef DEBUG_ROMPREFIX
|
|
call print_installed
|
|
#endif
|
|
installed:
|
|
popw %ds
|
|
popw %ax
|
|
movw $0x20,%ax
|
|
lret
|
|
|
|
start_int: /* clobber magic id, so that we will */
|
|
#ifdef DEBUG_ROMPREFIX
|
|
call print_start_int
|
|
#endif
|
|
xorw %ax,%ax /* not inadvertendly end up in an */
|
|
movw %ax,%ds /* endless loop */
|
|
movw %ax, SCRATCHVEC+4
|
|
movw SCRATCHVEC+2, %ax /* restore original INT19h handler */
|
|
movw %ax, BOOT_INT_VEC+2
|
|
movw SCRATCHVEC, %ax
|
|
movw %ax, BOOT_INT_VEC
|
|
pushl %eax /* padding */
|
|
pushw $EXIT_VIA_BOOT_INT
|
|
jmp invoke
|
|
#endif /* DELAYED_INT */
|
|
|
|
|
|
|
|
|
|
legacyentry:
|
|
#ifdef DEBUG_ROMPREFIX
|
|
call print_legacyentry
|
|
#endif
|
|
pushw $EXIT_VIA_LRET
|
|
jmp invoke
|
|
|
|
|
|
|
|
#ifdef PCI_PNP_HEADER
|
|
pnpentry:
|
|
#ifdef DEBUG_ROMPREFIX
|
|
call print_bev
|
|
#endif
|
|
pushl %eax /* padding */
|
|
pushw $EXIT_VIA_INT_18
|
|
jmp invoke
|
|
#endif /* PCI_PNP_HEADER */
|
|
|
|
|
|
invoke:
|
|
/* Store ROM segment and size on stack */
|
|
pushw %ax
|
|
pushw %ds
|
|
pushw %cs
|
|
movzbw %cs:(size-_prefix), %ax
|
|
shlw $9, %ax /* 512-byte blocks */
|
|
pushw %ax
|
|
/* Relocate to free base memory, switch stacks */
|
|
pushw $12 /* Preserve exit code & far ret addr */
|
|
call prelocate
|
|
/* We are now running in RAM */
|
|
popw %ax /* padding */
|
|
movw %cs, %ax
|
|
movw %ax, %ds
|
|
popw %ds:(_prefix_rom+2) /* ROM size */
|
|
popw %ds:(_prefix_rom+0) /* ROM segment */
|
|
popw %ds /* Original %ds */
|
|
popw %ax /* Original %ax */
|
|
pushw %ax /* 4-byte alignment */
|
|
pushl $8 /* Preserve exit code & far ret addr */
|
|
pushw $0 /* Set null return address */
|
|
jmp _start
|
|
|
|
|
|
.section ".text16", "ax", @progbits
|
|
prefix_exit:
|
|
popw %ax /* padding */
|
|
popw %ax /* %ax = exit code */
|
|
cmpw $EXIT_VIA_LRET, %ax
|
|
jne 1f
|
|
/* Exit via LRET */
|
|
lret
|
|
1: addw $4, %sp /* Strip padding */
|
|
cmpw $EXIT_VIA_BOOT_INT, %ax
|
|
jne 2f
|
|
/* Exit via int BOOT_INT */
|
|
int $BOOT_INT /* Try original vector */
|
|
2: /* Exit via int $0x18 */
|
|
int $0x18 /* As per BIOS Boot Spec, next dev */
|
|
prefix_exit_end:
|
|
.previous
|
|
|
|
|
|
|
|
/* UNDI loader needs to be rewritten to use new mechanism */
|
|
#if 0
|
|
|
|
#ifdef PXE_EXPORT
|
|
|
|
#define PXENV_UNDI_LOADER 0x104d
|
|
|
|
.section ".prefix"
|
|
UNDILoader:
|
|
/* Loader API is different to the usual PXE API; there is no
|
|
* opcode on the stack. We arrange the stack to look like a
|
|
* normal PXE API call; this makes the Etherboot internals
|
|
* cleaner and avoids adding an extra API type just for the
|
|
* PXE loader.
|
|
*/
|
|
pushw %bx
|
|
movw %sp, %ax /* Store original %ss:sp */
|
|
pushw %ss
|
|
pushw %ax
|
|
pushl %eax /* Space for loader structure ptr */
|
|
pushw %bp
|
|
movw %sp, %bp
|
|
movw 16(%bp), %ax /* Copy loader structure ptr */
|
|
movw %ax, 2(%bp)
|
|
movw 18(%bp), %ax
|
|
movw %ax, 4(%bp)
|
|
popw %bp
|
|
pushw $PXENV_UNDI_LOADER /* PXE 'opcode' */
|
|
pushl %eax /* dummy return address */
|
|
/* Stack now looks like a normal PXE API call */
|
|
/* Store ROM segment and size on stack */
|
|
pushw %ax
|
|
pushw %cs
|
|
movzbw %cs:(size-_prefix), %ax
|
|
shlw $9, %ax /* 512-byte blocks */
|
|
pushw %ax
|
|
/* Unpack Etherboot into temporarily claimed base memory */
|
|
pushw $20 /* Dummy ret, PXE params, orig ss:sp */
|
|
call prelocate
|
|
popw %ax /* discard */
|
|
popw %cs:(_prefix_rom+2) /* ROM size */
|
|
popw %cs:(_prefix_rom+0) /* ROM segment */
|
|
popw %ax /* Original %ax */
|
|
/* Inhibit automatic deallocation of base memory */
|
|
movl $0, %cs:_prefix_image_basemem
|
|
/* Make PXE API call to Etherboot */
|
|
pushl $0x201 /* PXE API version */
|
|
/* Need to USE_INTERNAL_STACK, since we will call relocate() */
|
|
pushl $(EB_OPCODE_PXE|EB_USE_INTERNAL_STACK) /* PXE API call type */
|
|
call _entry
|
|
addw $18, %sp /* discard */
|
|
popw %bx /* Restore original %ss:sp */
|
|
popw %ss
|
|
movw %bx, %sp
|
|
popw %bx
|
|
call deprelocate
|
|
lret $2 /* Skip our PXE 'opcode' */
|
|
#endif /* PXE_EXPORT */
|
|
|
|
#endif /* 0 */
|
|
|
|
#ifdef DEBUG_ROMPREFIX
|
|
.section ".prefix"
|
|
|
|
print_bcv:
|
|
pushw %si
|
|
movw $1f-_prefix, %si
|
|
call print_message
|
|
popw %si
|
|
ret
|
|
1: .asciz "ROM detected\r\n"
|
|
|
|
print_bev:
|
|
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"
|
|
|
|
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
|
|
je 2f
|
|
movw $0x0007, %bx /* page 0, attribute 7 (normal) */
|
|
movb $0x0e, %ah /* write char, tty mode */
|
|
int $0x10
|
|
jmp 1b
|
|
2: ret
|
|
|
|
#endif
|