diff options
Diffstat (limited to 'src/VBox/Devices/PC/BIOS/orgs.asm')
| -rw-r--r-- | src/VBox/Devices/PC/BIOS/orgs.asm | 2069 |
1 files changed, 2069 insertions, 0 deletions
diff --git a/src/VBox/Devices/PC/BIOS/orgs.asm b/src/VBox/Devices/PC/BIOS/orgs.asm new file mode 100644 index 00000000..1706b71d --- /dev/null +++ b/src/VBox/Devices/PC/BIOS/orgs.asm @@ -0,0 +1,2069 @@ +; $Id: orgs.asm $ +;; @file +; ??? +; + +; +; Copyright (C) 2006-2019 Oracle Corporation +; +; This file is part of VirtualBox Open Source Edition (OSE), as +; available from http://www.virtualbox.org. This file is free software; +; you can redistribute it and/or modify it under the terms of the GNU +; General Public License (GPL) as published by the Free Software +; Foundation, in version 2 as it comes in the "COPYING" file of the +; VirtualBox OSE distribution. VirtualBox OSE is distributed in the +; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. +; -------------------------------------------------------------------- +; +; This code is based on: +; +; ROM BIOS for use with Bochs/Plex86/QEMU emulation environment +; +; Copyright (C) 2002 MandrakeSoft S.A. +; +; MandrakeSoft S.A. +; 43, rue d'Aboukir +; 75002 Paris - France +; http://www.linux-mandrake.com/ +; http://www.mandrakesoft.com/ +; +; This library is free software; you can redistribute it and/or +; modify it under the terms of the GNU Lesser General Public +; License as published by the Free Software Foundation; either +; version 2 of the License, or (at your option) any later version. +; +; This library is distributed in the hope that it will be useful, +; but WITHOUT ANY WARRANTY; without even the implied warranty of +; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +; Lesser General Public License for more details. +; +; You should have received a copy of the GNU Lesser General Public +; License along with this library; if not, write to the Free Software +; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA +; + +; Oracle LGPL Disclaimer: For the avoidance of doubt, except that if any license choice +; other than GPL or LGPL is available it will apply instead, Oracle elects to use only +; the Lesser General Public License version 2.1 (LGPLv2) at this time for any software where +; a choice of LGPL license versions is made available with the language indicating +; that LGPLv2 or any later version may be used, or where a choice of which version +; of the LGPL is applied is otherwise unspecified. + + +include commondefs.inc + +EBDA_SEG equ 09FC0h ; starts at 639K +EBDA_SIZE equ 1 ; 1K +BASE_MEM_IN_K equ (640 - EBDA_SIZE) + +CMOS_ADDR equ 070h +CMOS_DATA equ 071h + + +PIC_CMD_EOI equ 020h +PIC_MASTER equ 020h +PIC_SLAVE equ 0A0h + +BIOS_FIX_BASE equ 0E000h + +if VBOX_BIOS_CPU ge 80286 +SYS_MODEL_ID equ 0FCh ; PC/AT +else +SYS_MODEL_ID equ 0FBh ; PC/XT +endif +SYS_SUBMODEL_ID equ 0 +BIOS_REVISION equ 1 + +BIOS_BUILD_DATE equ '06/23/99' +BIOS_COPYRIGHT equ 'Oracle VM VirtualBox BIOS' + +BX_ROMBIOS32 equ 0 +BX_CALL_INT15_4F equ 1 + +;; Set a fixed BIOS location, with a marker for verification +BIOSORG macro addr, addr_minus_two +.errnz (addr - 2 - addr_minus_two) ;; Couldn't convince wasm to accept $ here. Would've save us a lot of bother and ugly SED. + BIOSORG_CHECK_BEFORE addr_minus_two + org addr - BIOS_FIX_BASE - 2 + db 'XM' + BIOSORG_CHECK addr + endm + +;; Set an interrupt vector (not very efficient if multiple vectors are +;; programmed in one go) +SET_INT_VECTOR macro vec, segm, offs + mov ax, offs + mov ds:[vec*4], ax + mov ax, segm + mov ds:[vec*4+2], ax +endm + +; Set up an environment C code expects. DS must point to the BIOS segment +; and the direction flag must be cleared(!) +C_SETUP macro + push cs + pop ds + cld +endm + + +;; External function in separate modules +extrn _dummy_isr_function:near +extrn _log_bios_start:near +extrn _nmi_handler_msg:near +extrn _int18_panic_msg:near +extrn _int09_function:near +extrn _int13_diskette_function:near +extrn _int13_eltorito:near +extrn _int13_cdemu:near +extrn _int13_cdrom:near +extrn _cdemu_isactive:near +extrn _cdemu_emulated_drive:near +extrn _int13_harddisk:near +extrn _int13_harddisk_ext:near +extrn _int14_function:near +extrn _int15_function:near +extrn _int15_function_mouse:near +extrn _int16_function:near +extrn _int17_function:near +extrn _int19_function:near +extrn _int1a_function:near +extrn _pci16_function:near +extrn _int70_function:near +extrn _int74_function:near +extrn _apm_function:near +extrn _ata_init:near +extrn _scsi_init:near +extrn _ata_detect:near +extrn _cdemu_init:near +extrn _keyboard_init:near +extrn _print_bios_banner:near +extrn _inv_op_handler:near +extrn rom_scan_:near +ifdef VBOX_WITH_AHCI +extrn _ahci_init:near +endif +if VBOX_BIOS_CPU ge 80286 +extrn _int15_blkmove:near +endif +if VBOX_BIOS_CPU ge 80386 +extrn _int15_function32:near +extrn _apic_setup:near +endif + + +;; Symbols referenced from C code +public _diskette_param_table +public _pmode_IDT +public _rmode_IDT +public post +public eoi_both_pics +public rtc_post + +;; Additional publics for easier disassembly and debugging +ifndef DEBUG + DEBUG equ 1 +endif +ifdef DEBUG + +public int08_handler +public int0e_handler +public int11_handler +public int12_handler +public int13_handler +public int13_relocated +if VBOX_BIOS_CPU eq 8086 +public jmp_call_ret_int13_out +endif +public int15_handler +public int17_handler +public int19_handler +public int19_relocated +public dummy_iret +public nmi +public rom_fdpt +public cpu_reset +public normal_post +public eoi_jmp_post +public no_eoi_jmp_post +public eoi_master_pic +public ebda_post +public seg_40_value +public hard_drive_post +public int13_legacy +public int70_handler +public int75_handler +public int15_handler32 +public int15_handler_mouse +public iret_modify_cf +public init_pic +public floppy_post +public int13_out +public int13_disk +public int13_notfloppy +public int13_legacy +public int13_noeltorito +public int1c_handler +public int10_handler +public int74_handler +public int76_handler +public detect_parport +public detect_serial +public font8x8 + +endif + +;; Keyboard related constants +KBDC_DISABLE EQU 0ADh +KBDC_ENABLE EQU 0AEh +KBC_CMD EQU 64h +KBC_DATA EQU 60h + + +;; NOTE: The last 8K of the ROM BIOS are peppered with fixed locations which +;; must be retained for compatibility. As a consequence, some of the space is +;; going to be wasted, but the gaps should be filled with miscellaneous code +;; and data when possible. + +SET_DEFAULT_CPU_286 + +BIOSSEG segment 'CODE' + assume cs:BIOSSEG + +;; +;; Start of fixed code - eoi_jmp_post is kept near here to allow short jumps. +;; + BIOSORG 0E030h, 0E02Eh +eoi_both_pics: + mov al, PIC_CMD_EOI + out PIC_SLAVE, al +eoi_master_pic: + mov al, PIC_CMD_EOI + out PIC_MASTER, al + ret + + ;; routine to write the pointer in DX:AX to memory starting + ;; at DS:BX (repeat CX times) + ;; - modifies BX, CX +set_int_vects proc near + + mov [bx], ax + mov [bx+2], dx + add bx, 4 + loop set_int_vects + ret + +set_int_vects endp + +eoi_jmp_post: +;; Calling eoi_both_pics can't be done because it writes to stack, potentially +;; corrupting memory. AT BIOS also only clears the master PIC, not both. + ;; clear keyboard buffer (and possible interrupt) + in al, KBC_DATA + mov al, PIC_CMD_EOI + out PIC_MASTER, al + +no_eoi_jmp_post: + mov ax, 40h + mov ds, ax + jmp dword ptr ds:[67h] + +seg_40_value: dw 40h ;; Replaces a push 40; pop ds. + +;; -------------------------------------------------------- +;; POST entry point +;; -------------------------------------------------------- + BIOSORG 0E05Bh, 0E059h +post: + cli + +if VBOX_BIOS_CPU ge 80286 + ;; Check if in protected (V86) mode. If so, the CPU needs + ;; to be reset. + .286p + smsw ax + test ax, 1 + jz in_real_mode + SET_DEFAULT_CPU_286 +else + jmp in_real_mode +endif + + ;; Reset processor to get out of protected mode. Use system + ;; port instead of KBC. +reset_sys: + mov al, 1 + out 92h, al + jmp $ ; not strictly necessary in a VM + + +in_real_mode: + ;; read the CMOS shutdown status + mov al, 0Fh + out CMOS_ADDR, al + in al, CMOS_DATA + + ;; save status + xchg ah, al + + ;; Check KBC self-test/shutdown flag. If it is set, we need + ;; to check for a reboot attempt. + in al, 64h + test al, 4 ; clear flag indicates cold boot + jz cont_post + + ;; Warm boot, check the shutdown byte. + mov al, ah + or al, al + jnz cont_post + + ;; Warm boot but shutdown byte is zero. This is either a warm + ;; boot request or an attempt to reset the system via triple + ;; faulting the CPU or similar. Check reboot flag. + ;; NB: At this point, registers need not be preserved. + mov ds, cs:[seg_40_value] + cmp word ptr ds:[72h], 1234h + jnz reset_sys ; trigger system reset + +cont_post: + ;; reset the shutdown status in CMOS + mov al, 0Fh + out CMOS_ADDR, al + mov al, 0 + out CMOS_DATA, al + + ;; pre-check the shutdown status - shutdown codes 9/A leave + ;; the hardware alone + mov al, ah + cmp al, 09h + jz check_shutdown + cmp al, 0Ah + jz check_shutdown + + xor al, al + + ;; reset the DMA controllers + out 00Dh, al + out 0DAh, al + + ;; then initialize the DMA controllers + mov al, 0C0h + out 0D6h, al ; enable channel 4 cascade + mov al, 0 + out 0D4h, al ; unmask channel 4 + +check_shutdown: + ;; examine the shutdown status code + mov al, ah + cmp al, 0 + jz normal_post + + cmp al, 0Dh + jae normal_post + cmp al, 9 + jne check_next_std + jmp return_blkmove +check_next_std: + + mov sp, 400h + ;; 05h = EOI + jump through 40:67 + cmp al, 5 + je eoi_jmp_post + ;; 0ah = jump through 40:67 (no EOI) ;ba x 1 %fe05b ; ba x 1 %18b81 + cmp al, 0ah + je no_eoi_jmp_post + + ;; any other shutdown status values are ignored + ;; OpenSolaris sets the status to 0Ah in some cases? + jmp normal_post + +normal_post: + ;; shutdown code 0: normal startup + + ;; Set up the stack top at 0:7800h. The stack should not be + ;; located above 0:7C00h; that conflicts with PXE, which + ;; considers anything above that address to be fair game. + ;; The traditional locations are 30:100 (PC) or 0:400 (PC/AT). + mov ax, 7800h + mov sp, ax + xor ax, ax + mov ds, ax + mov ss, ax + + ;; clear the bottom of memory except for the word at 40:72 + ;; TODO: Why not clear all of it? What's the point? + mov es, ax + xor di, di + cld + mov cx, 0472h / 2 + rep stosw + inc di + inc di + mov cx, (1000h - 0472h - 2) / 2 + rep stosw + + ;; clear the remaining base memory except for the top + ;; of the EBDA (the MP table is planted there) + xor bx, bx +memory_zero_loop: + add bx, 1000h + cmp bx, 9000h + jae memory_cleared + mov es, bx + xor di, di + mov cx, 8000h ; 32K words + rep stosw + jmp memory_zero_loop +memory_cleared: + mov es, bx + xor di, di + mov cx, 7FF8h ; all but the last 16 bytes + rep stosw + xor bx, bx + + + C_SETUP + call _log_bios_start + +if VBOX_BIOS_CPU ge 80386 + call pmode_setup +endif + + ;; set all interrupts in 00h-5Fh range to default handler + xor bx, bx + mov ds, bx + mov cx, 60h ; leave the rest as zeros + mov ax, dummy_iret + mov dx, BIOSSEG + call set_int_vects + + ;; also set 68h-77h to default handler; note that the + ;; 60h-67h range must contain zeros for certain programs + ;; to function correctly + mov bx, 68h * 4 + mov cx, 10h + call set_int_vects + + ;; base memory in K to 40:13 + mov ax, BASE_MEM_IN_K + mov ds:[413h], ax + + ;; manufacturing test at 40:12 + ;; zeroed out above + + ;; set up various service vectors + ;; TODO: This should use the table at FEF3h instead + SET_INT_VECTOR 06h, BIOSSEG, int06_handler + SET_INT_VECTOR 11h, BIOSSEG, int11_handler + SET_INT_VECTOR 12h, BIOSSEG, int12_handler + SET_INT_VECTOR 15h, BIOSSEG, int15_handler + SET_INT_VECTOR 17h, BIOSSEG, int17_handler + SET_INT_VECTOR 18h, BIOSSEG, int18_handler + SET_INT_VECTOR 19h, BIOSSEG, int19_handler + SET_INT_VECTOR 1Ch, BIOSSEG, int1c_handler + + call ebda_post + + ;; Initialize PCI devices. This can and should be done early. +if VBOX_BIOS_CPU ge 80386 ; (Impossible to do on 16-bit CPUs.) + call pcibios_init_iomem_bases + call pcibios_init_irqs +endif + SET_INT_VECTOR 1Ah, BIOSSEG, int1a_handler + + ;; PIT setup + SET_INT_VECTOR 08h, BIOSSEG, int08_handler + mov al, 34h ; timer 0, binary, 16-bit, mode 2 + out 43h, al + mov al, 0 ; max count -> ~18.2 Hz + out 40h, al + out 40h, al + + ;; video setup - must be done before POSTing VGA ROM + SET_INT_VECTOR 10h, BIOSSEG, int10_handler + + ;; keyboard setup + SET_INT_VECTOR 09h, BIOSSEG, int09_handler + SET_INT_VECTOR 16h, BIOSSEG, int16_handler + + xor ax, ax + mov ds, ax + ;; TODO: What's the point? The BDA is zeroed already?! + mov ds:[417h], al ; keyboard shift flags, set 1 + mov ds:[418h], al ; keyboard shift flags, set 2 + mov ds:[419h], al ; keyboard Alt-numpad work area + mov ds:[471h], al ; keyboard Ctrl-Break flag + mov ds:[497h], al ; keyboard status flags 4 + mov al, 10h + mov ds:[496h], al ; keyboard status flags 3 + + mov bx, 1Eh + mov ds:[41Ah], bx ; keyboard buffer head + mov ds:[41Ch], bx ; keyboard buffer tail + mov ds:[480h], bx ; keyboard buffer start + mov bx, 3Eh + mov ds:[482h], bx ; keyboard buffer end + + ;; store CMOS equipment byte in BDA + mov al, 14h + out CMOS_ADDR, al + in al, CMOS_DATA + mov ds:[410h], al + + push ds + C_SETUP + + ;; Scan for video ROMs in the C000-C800 range. This is done + ;; early so that errors are displayed on the screen. + mov ax, 0C000h + mov dx, 0C800h + call rom_scan_ + + ;; Initialize the keyboard + call _keyboard_init + pop ds + + ;; parallel setup + SET_INT_VECTOR 0Fh, BIOSSEG, dummy_iret + xor ax, ax + mov ds, ax + xor bx, bx + mov cl, 14h ; timeout value + mov dx, 378h ; parallel port 1 + call detect_parport + mov dx, 278h ; parallel port 2 + call detect_parport + DO_shl bx, 0Eh + mov ax, ds:[410h] ; equipment word + and ax, 3FFFh + or ax, bx ; set number of parallel ports + mov ds:[410h], ax ; store in BDA + + ;; Serial setup + SET_INT_VECTOR 0Bh, BIOSSEG, dummy_isr ; IRQ 3 + SET_INT_VECTOR 0Ch, BIOSSEG, dummy_isr ; IRQ 4 + SET_INT_VECTOR 14h, BIOSSEG, int14_handler + xor bx, bx + mov cl, 0Ah ; timeout value + mov dx, 3F8h ; first serial address + call detect_serial + mov dx, 2F8h ; second serial address + call detect_serial + mov dx, 3E8h ; third serial address + call detect_serial + mov dx, 2E8h ; fourth serial address + call detect_serial + DO_shl bx, 9 + mov ax, ds:[410h] ; equipment word + and ax, 0F1FFh ; bits 9-11 determine serial ports + or ax, bx + mov ds:[410h], ax + + ;; CMOS RTC + SET_INT_VECTOR 4Ah, BIOSSEG, dummy_iret ; TODO: redundant? + SET_INT_VECTOR 70h, BIOSSEG, int70_handler + ;; BIOS DATA AREA 4CEh ??? + call rtc_post + + jmp norm_post_cont + + +;; -------------------------------------------------------- +;; NMI handler +;; -------------------------------------------------------- + BIOSORG 0E2C3h, 0E2C1h +nmi: + C_SETUP + call _nmi_handler_msg + iret + +int75_handler: + out 0F0h, al ; clear IRQ13 + call eoi_both_pics + int 2 ; emulate legacy NMI + iret + + +hard_drive_post proc near + + xor ax, ax + mov ds, ax + ;; TODO: Didn't we just clear the entire EBDA? + mov ds:[474h], al ; last HD operation status + mov ds:[477h], al ; HD port offset (XT only???) + mov ds:[48Ch], al ; HD status register + mov ds:[48Dh], al ; HD error register + mov ds:[48Eh], al ; HD task complete flag + mov al, 0C0h + mov ds:[476h], al ; HD control byte + ;; set up hard disk interrupt vectors + SET_INT_VECTOR 13h, BIOSSEG, int13_handler + SET_INT_VECTOR 76h, BIOSSEG, int76_handler + ;; The ATA init code sets up INT 41h/46h FDPT pointers + ret + +hard_drive_post endp + + +norm_post_cont: + ;; PS/2 mouse setup + SET_INT_VECTOR 74h, BIOSSEG, int74_handler + + ;; IRQ 13h (FPU exception) setup + SET_INT_VECTOR 75h, BIOSSEG, int75_handler + + call init_pic + + C_SETUP + +if VBOX_BIOS_CPU ge 80386 + ;; Set up local APIC + .386 + pushad + call _apic_setup + popad + SET_DEFAULT_CPU_286 +endif + + ;; ATA/ATAPI driver setup + call _ata_init + call _ata_detect + +ifdef VBOX_WITH_AHCI + ; AHCI driver setup + ;; TODO: AHCI initialization needs timer, but enabling + ;; interrupts elsewhere may be risky. Just do it around + ;; the AHCI init. + sti + call _ahci_init + cli +endif + +ifdef VBOX_WITH_SCSI + ; SCSI driver setup + call _scsi_init +endif + + ;; floppy setup + call floppy_post + + ;; hard drive setup + call hard_drive_post + + C_SETUP ; in case assembly code changed things + ;; Scan for additional ROMs in the C800-EFFF range + mov ax, 0C800h + mov dx, 0F000h + call rom_scan_ + +if VBOX_BIOS_CPU ge 80386 + ;; The POST code does not bother preserving high bits of the + ;; 32-bit registers. Now is a good time to clear them so that + ;; there's no garbage left in high bits. + .386 + xor eax, eax + xor ebx, ebx + xor ecx, ecx + xor edx, edx + .286 +endif + + call _print_bios_banner + + ;; El Torito floppy/hard disk emulation + call _cdemu_init + + ; TODO: what's the point of enabling interrupts here?? + sti ; enable interrupts + int 19h + ;; does not return here + sti +wait_forever: + hlt + jmp wait_forever + cli + hlt + + +;; +;; Return from block move (shutdown code 09h). Care must be taken to disturb +;; register and memory state as little as possible. +;; +return_blkmove: + .286p + mov ax, 40h + mov ds, ax + ;; restore user stack + mov ss, ds:[69h] + mov sp, ds:[67h] + ;; reset A20 gate + in al, 92h + and al, 0FDh + out 92h, al + ;; ensure proper real mode IDT + lidt fword ptr cs:_rmode_IDT + ;; restore user segments + pop ds + pop es + ;; set up BP + mov bp, sp + ;; restore status code + in al, 80h + mov [bp+15], al + ;; set ZF/CF + cmp ah,al ; AH is zero here! + ;; restore registers and return + popa + sti + retf 2 + SET_DEFAULT_CPU_286 + + +;; -------------------------------------------------------- +;; INT 13h handler - Disk services +;; -------------------------------------------------------- + BIOSORG 0E3FEh, 0E3FCh + +int13_handler: + jmp int13_relocated + + +;; -------------------------------------------------------- +;; Fixed Disk Parameter Table +;; -------------------------------------------------------- + BIOSORG_CHECK 0E401h ; fixed wrt preceding + +rom_fdpt: + +;; -------------------------------------------------------- +;; INT 19h handler - Boot load service +;; -------------------------------------------------------- + BIOSORG 0E6F2h, 0E6F0h + +int19_handler: + jmp int19_relocated + + + +;; -------------------------------------------------------- +;; System BIOS Configuration Table +;; -------------------------------------------------------- + BIOSORG_CHECK 0E6F5h ; fixed wrt preceding +; must match BIOS_CONFIG_TABLE +bios_cfg_table: + dw 9 ; table size in bytes + db SYS_MODEL_ID + db SYS_SUBMODEL_ID + db BIOS_REVISION + ; Feature byte 1 + ; b7: 1=DMA channel 3 used by hard disk + ; b6: 1=2 interrupt controllers present + ; b5: 1=RTC present + ; b4: 1=BIOS calls int 15h/4Fh for every key + ; b3: 1=wait for extern event supported (Int 15h/41h) + ; b2: 1=extended BIOS data area used + ; b1: 0=AT or ESDI bus, 1=MicroChannel + ; b0: 1=Dual bus (MicroChannel + ISA) +ifdef BX_CALL_INT15_4F + db 74h; or USE_EBDA +else + db 64h; or USE_EBDA +endif + ; Feature byte 2 + ; b7: 1=32-bit DMA supported + ; b6: 1=int16h, function 9 supported + ; b5: 1=int15h/C6h (get POS data) supported + ; b4: 1=int15h/C7h (get mem map info) supported + ; b3: 1=int15h/C8h (en/dis CPU) supported + ; b2: 1=non-8042 kb controller + ; b1: 1=data streaming supported + ; b0: reserved + db 40h + ; Feature byte 3 + ; b7: not used + ; b6: reserved + ; b5: reserved + ; b4: POST supports ROM-to-RAM enable/disable + ; b3: SCSI on system board + ; b2: info panel installed + ; b1: Initial Machine Load (IML) system - BIOS on disk + ; b0: SCSI supported in IML + db 0 + ; Feature byte 4 + ; b7: IBM private + ; b6: EEPROM present + ; b5-3: ABIOS presence (011 = not supported) + ; b2: private + ; b1: memory split above 16Mb supported + ; b0: POSTEXT directly supported by POST + db 0 + ; Feature byte 5 (IBM) + ; b1: enhanced mouse + ; b0: flash EPROM + db 0 + + +;; -------------------------------------------------------- +;; Baud Rate Generator Table +;; -------------------------------------------------------- + BIOSORG 0E729h, 0E727h + + +;; -------------------------------------------------------- +;; INT 14h handler - Serial Communication Service +;; -------------------------------------------------------- + BIOSORG 0E739h, 0E737h +int14_handler: + push ds + push es + DO_pusha + C_SETUP + call _int14_function + DO_popa + pop es + pop ds + iret + + + +;; +;; Handler for unexpected hardware interrupts +;; +dummy_isr: + push ds + push es + DO_pusha + C_SETUP + call _dummy_isr_function + DO_popa + pop es + pop ds + iret + + +init_pic proc near + + mov al, 11h ; send init commands + out PIC_MASTER, al + out PIC_SLAVE, al + mov al, 08h ; base 08h + out PIC_MASTER+1, al + mov al, 70h ; base 70h + out PIC_SLAVE+1, al + mov al, 04h ; master PIC + out PIC_MASTER+1, al + mov al, 02h ; slave PIC + out PIC_SLAVE+1, al + mov al, 01h + out PIC_MASTER+1, al + out PIC_SLAVE+1, al + mov al, 0B8h ; unmask IRQs 0/1/2/6 + out PIC_MASTER+1, al + mov al, 08Fh + out PIC_SLAVE+1, al ; unmask IRQs 12/13/14 + ret + +init_pic endp + +ebda_post proc near + + SET_INT_VECTOR 0Dh, BIOSSEG, dummy_isr ; IRQ 5 + SET_INT_VECTOR 0Fh, BIOSSEG, dummy_isr ; IRQ 7 + SET_INT_VECTOR 72h, BIOSSEG, dummy_isr ; IRQ 10 + SET_INT_VECTOR 73h, BIOSSEG, dummy_isr ; IRQ 11 + SET_INT_VECTOR 77h, BIOSSEG, dummy_isr ; IRQ 15 + + mov ax, EBDA_SEG + mov ds, ax + mov byte ptr ds:[0], EBDA_SIZE + ;; store EBDA seg in 40:0E + xor ax, ax + mov ds, ax + mov word ptr ds:[40Eh], EBDA_SEG + ret + +ebda_post endp + + + +;; -------------------------------------------------------- +;; INT 16h handler - Keyboard service +;; -------------------------------------------------------- + BIOSORG 0E82Eh, 0E82Ch +int16_handler: + sti + ;; Flags are saved *after* enabling interrupts, and with + ;; implicitly cleared TF. Software may depend on that. + pushf + push es + push ds + DO_pusha + + cmp ah, 0 + je int16_F00 + + cmp ah, 10h + je int16_F00 + + C_SETUP + call _int16_function + DO_popa + pop ds + pop es + add sp, 2 ; Skip saved flags + iret + +int16_F00: + mov bx, 40h ; TODO: why 40h here and 0 elsewhere? + mov ds, bx +int16_wait_for_key: + cli + mov bx, ds:[1Ah] + cmp bx, ds:[1Ch] + jne int16_key_found + sti + nop +; TODO: review/enable? +if 0 + push ax + mov ax, 9002h + int 15h + pop ax +endif + jmp int16_wait_for_key + +int16_key_found: + C_SETUP + call _int16_function + DO_popa + pop ds + pop es + add sp, 2 ; Skip saved flags +; TODO: review/enable? If so, flags should be restored here? +if 0 + push ax + mov ax, 9202h + int 15h + pop ax +endif + iret + + +if VBOX_BIOS_CPU ge 80386 +;; Quick and dirty protected mode entry/exit routines +include pmode.inc + +;; Initialization code which needs to run in protected mode (LAPIC etc.) +include pmsetup.inc +endif + + +;; -------------------------------------------------------- +;; INT 09h handler - Keyboard ISR (IRQ 1) +;; -------------------------------------------------------- + BIOSORG 0E987h, 0E985h +int09_handler: + cli ; TODO: why? they're off already! + push ax + mov al, KBDC_DISABLE + out KBC_CMD, al + + in al, KBC_DATA + push ds + DO_pusha + cld ; Before INT 15h (and any C code) +ifdef BX_CALL_INT15_4F + mov ah, 4Fh + stc + int 15h ; keyboard intercept + jnc int09_done +endif + sti ; Only after calling INT 15h + + ;; check for extended key + cmp al, 0E0h + jne int09_check_pause + xor ax, ax + mov ds, ax + or byte ptr ds:[496h], 2 ; mf2_state |= 0x02 + jmp int09_done + +int09_check_pause: + cmp al, 0E1h ; pause key? + jne int09_process_key + xor ax, ax + mov ds, ax + or byte ptr ds:[496h], 1 ; mf2_state | 0x01 + jmp int09_done + +int09_process_key: + push es + C_SETUP + call _int09_function + pop es + +int09_done: + DO_popa + pop ds + cli + call eoi_master_pic + + mov al, KBDC_ENABLE + out KBC_CMD, al + pop ax + iret + + +;; -------------------------------------------------------- +;; INT 06h handler - Invalid Opcode Exception +;; -------------------------------------------------------- + +int06_handler: + DO_pusha + push es + push ds + C_SETUP + call _inv_op_handler + pop ds + pop es + DO_popa + iret + +;; -------------------------------------------------------- +;; INT 13h handler - Diskette service +;; -------------------------------------------------------- + BIOSORG 0EC59h, 0EC57h +int13_diskette: + jmp int13_noeltorito + + + +;; -------------------------------------------------------- +;; INT 13h handler - Disk service +;; -------------------------------------------------------- +int13_relocated: + ;; check for an El-Torito function + cmp ah, 4Ah + jb int13_not_eltorito + + cmp ah, 4Dh + ja int13_not_eltorito + + DO_pusha + push es + push ds + C_SETUP ; TODO: setup C envrionment only once? + DO_JMP_CALL_EX _int13_eltorito, int13_out, jmp_call_ret_int13_out ; ELDX not used +if VBOX_BIOS_CPU eq 8086 +jmp_call_ret_int13_out: dw offset int13_out +endif + +int13_not_eltorito: + push es + push ax ; TODO: better register save/restore + push bx + push cx + push dx + + ;; check if emulation is active + call _cdemu_isactive + cmp al, 0 + je int13_cdemu_inactive + + ;; check if access to the emulated drive + call _cdemu_emulated_drive + pop dx ; recover dx (destroyed by C code) + push dx + cmp al, dl ; INT 13h on emulated drive + jne int13_nocdemu + + pop dx + pop cx + pop bx + pop ax + pop es + + DO_pusha + push es + push ds + C_SETUP ; TODO: setup environment only once? + + DO_JMP_CALL_EX _int13_cdemu, int13_out, jmp_call_ret_int13_out ; ELDX not used + +int13_nocdemu: + and dl, 0E0h ; mask to get device class + cmp al, dl + jne int13_cdemu_inactive + + pop dx + pop cx + pop bx + pop ax + pop es + + push ax + push cx + push dx + push bx + + dec dl ; real drive is dl - 1 + jmp int13_legacy + +int13_cdemu_inactive: + pop dx + pop cx + pop bx + pop ax + pop es + +int13_noeltorito: + push ax + push cx + push dx + push bx +int13_legacy: + push dx ; push eltorito dx in place of sp + push bp + push si + push di + push es + push ds + C_SETUP ; TODO: setup environment only once? + + ;; now the registers can be restored with + ;; pop ds; pop es; DO_popa; iret + test dl, 80h ; non-removable? + jnz int13_notfloppy + + DO_JMP_CALL_EX _int13_diskette_function, int13_out, jmp_call_ret_int13_out + +int13_notfloppy: + cmp dl, 0E0h + jb int13_notcdrom + + ;; ebx may be modified, save here + ;; TODO: check/review 32-bit register use + ;; @todo figure if 80286/8086 variant is applicable. + .386 + shr ebx, 16 + push bx + call _int13_cdrom + pop bx + shl ebx, 16 + SET_DEFAULT_CPU_286 + jmp int13_out + +int13_notcdrom: +int13_disk: + cmp ah,40h + ja int13x + call _int13_harddisk + jmp int13_out + +int13x: + call _int13_harddisk_ext + +int13_out: + pop ds + pop es + DO_popa + iret + + + +; parallel port detection: port in dx, index in bx, timeout in cl +detect_parport proc near + + push dx + inc dx + inc dx + in al, dx + and al, 0DFh ; clear input mode + out dx, al + pop dx + mov al, 0AAh + out dx, al + in al, dx + cmp al, 0AAh + jne no_parport + + push bx + shl bx, 1 + mov [bx+408h], dx ; parallel I/O address + pop bx + mov [bx+478h], cl ; parallel printer timeout + inc bx +no_parport: + ret + +detect_parport endp + +; setial port detection: port in dx, index in bx, timeout in cl +detect_serial proc near + + push dx + inc dx + mov al, 2 + out dx, al + in al, dx + cmp al, 2 + jne no_serial + + inc dx + in al, dx + cmp al, 2 + jne no_serial + + dec dx + xor al, al + pop dx + push bx + shl bx, 1 + mov [bx+400h], dx ; serial I/O address + pop bx + mov [bx+47Ch], cl ; serial timeout + inc bx + ret + +no_serial: + pop dx + ret + +detect_serial endp + + +;; +;; POST: Floppy drive +;; +floppy_post proc near + + xor ax, ax + mov ds, ax + + ;; TODO: This code is really stupid. Zeroing the BDA byte + ;; by byte is dumb, and it's been already zeroed elsewhere! + mov al, 0 + mov ds:[43Eh], al ; drive 0/1 uncalibrated, no IRQ + mov ds:[43Fh], al ; motor status + mov ds:[440h], al ; motor timeout counter + mov ds:[441h], al ; controller status return code + mov ds:[442h], al ; hd/floppy ctlr status register + mov ds:[443h], al ; controller status register 1 + mov ds:[444h], al ; controller status register 2 + mov ds:[445h], al ; cylinder number + mov ds:[446h], al ; head number + mov ds:[447h], al ; sector number + mov ds:[448h], al ; bytes written + + mov ds:[48Bh], al ; configuration data + + mov al, 10h ; floppy drive type + out CMOS_ADDR, al + in al, CMOS_DATA + mov ah, al ; save drive type byte + +look_drive0: + ; TODO: pre-init bl to reduce jumps + DO_shr al, 4 ; drive 0 in high nibble + jz f0_missing ; jump if no drive + mov bl, 7 ; drv0 determined, multi-rate, chgline + jmp look_drive1 + +f0_missing: + mov bl, 0 ; no drive 0 + +look_drive1: + mov al, ah ; restore CMOS data + and al, 0Fh ; drive 1 in low nibble + jz f1_missing + or bl, 70h ; drv1 determined, multi-rate, chgline +f1_missing: + mov ds:[48Fh], bl ; store in BDA + + ;; TODO: See above. Dumb *and* redundant! + mov al, 0 + mov ds:[490h], al ; drv0 media state + mov ds:[491h], al ; drv1 media state + mov ds:[492h], al ; drv0 operational state + mov ds:[493h], al ; drv1 operational state + mov ds:[494h], al ; drv0 current cylinder + mov ds:[495h], al ; drv1 current cylinder + + mov al, 2 + out 0Ah, al ; unmask DMA channel 2 + + SET_INT_VECTOR 1Eh, BIOSSEG, _diskette_param_table + SET_INT_VECTOR 40h, BIOSSEG, int13_diskette + SET_INT_VECTOR 0Eh, BIOSSEG, int0e_handler ; IRQ 6 + + ret + +floppy_post endp + + +bcd_to_bin proc near + + ;; in : AL in packed BCD format + ;; out: AL in binary, AH always 0 +if VBOX_BIOS_CPU ge 80186 + shl ax, 4 + shr al, 4 +else + push cx + mov cl, 4 + shl ax, cl + shr al, cl + pop cx +endif + aad + ret + +bcd_to_bin endp + +rtc_post proc near + +if VBOX_BIOS_CPU lt 80386 ;; @todo fix loopy code below + ;; get RTC seconds + mov al, 0 + out CMOS_ADDR, al + in al, CMOS_DATA ; RTC seconds, in BCD + call bcd_to_bin ; ax now has seconds in binary + test al, al + xor ah, ah + mov dx, 0x1234 ; 18206507*0x100/1000000 = 0x1234 (4660.865792) + mul dx + mov cx, ax ; tick count in dx:cx + + ;; get RTC minutes + mov al, 2 + out CMOS_ADDR, al + in al, CMOS_DATA ; RTC minutes, in BCD + call bcd_to_bin ; eax now has minutes in binary + test al, al + jz rtc_post_hours +rtc_pos_min_loop: ; 18206507*60*0x100/1000000 = 0x44463 (279651.94752) + add cx, 0x4463 + adc dx, 0x0004 + dec al + jnz rtc_pos_min_loop + + ;; get RTC hours +rtc_post_hours: + mov al, 4 + out CMOS_ADDR, al + in al, CMOS_DATA ; RTC hours, in BCD + call bcd_to_bin ; eax now has hours in binary + test al, al + jz rtc_pos_shift +rtc_pos_hour_loop: ; 18206507*3600*0x100/1000000 = 0x100076C (16779116.8512) + add cx, 0x076C + adc dx, 0x0100 + dec al + jnz rtc_pos_hour_loop + +rtc_pos_shift: + mov cl, ch + mov ch, dl + mov dl, dh + xor dh, dh + mov ds:[46Ch], cx ; timer tick count + mov ds:[46Ch+2], dx ; timer tick count + mov ds:[470h], dh ; rollover flag + +else + .386 + ;; get RTC seconds + xor eax, eax + mov al, 0 + out CMOS_ADDR, al + in al, CMOS_DATA ; RTC seconds, in BCD + call bcd_to_bin ; eax now has seconds in binary + mov edx, 18206507 + mul edx + mov ebx, 1000000 + xor edx, edx + div ebx + mov ecx, eax ; total ticks in ecx + + ;; get RTC minutes + xor eax, eax + mov al, 2 + out CMOS_ADDR, al + in al, CMOS_DATA ; RTC minutes, in BCD + call bcd_to_bin ; eax now has minutes in binary + mov edx, 10923904 + mul edx + mov ebx, 10000 + xor edx, edx + div ebx + add ecx, eax ; add to total ticks + + ;; get RTC hours + xor eax, eax + mov al, 4 + out CMOS_ADDR, al + in al, CMOS_DATA ; RTC hours, in BCD + call bcd_to_bin ; eax now has hours in binary + mov edx, 65543427 + mul edx + mov ebx, 1000 + xor edx, edx + div ebx + add ecx, eax ; add to total ticks + + mov ds:[46Ch], ecx ; timer tick count + xor al, al ; TODO: redundant? + mov ds:[470h], al ; rollover flag + .286 +endif + ret + +rtc_post endp + + + +;; -------------------------------------------------------- +;; INT 0Eh handler - Diskette IRQ 6 ISR +;; -------------------------------------------------------- + BIOSORG 0EF57h, 0EF55h +int0e_handler: + push ax + push dx + mov dx, 3F4h + in al, dx + and al, 0C0h + cmp al, 0C0h + je int0e_normal + mov dx, 3F5h + mov al, 08h ; sense interrupt + out dx, al +int0e_loop1: + mov dx, 3F4h ; TODO: move out of the loop? + in al, dx + and al, 0C0h + cmp al, 0C0h + jne int0e_loop1 + +int0e_loop2: + mov dx, 3F5h ; TODO: inc/dec dx instead + in al, dx + mov dx, 3F4h + in al, dx + and al, 0C0h + cmp al, 0C0h + je int0e_loop2 + +int0e_normal: + push ds + xor ax, ax + mov ds, ax + call eoi_master_pic + ; indicate that an interrupt occurred + or byte ptr ds:[43Eh], 80h + pop ds + pop dx + pop ax + iret + + +;; -------------------------------------------------------- +;; Diskette Parameter Table +;; -------------------------------------------------------- + BIOSORG 0EFC7h, 0EFC5h +_diskette_param_table: + db 0AFh + db 2 ; HLT=1, DMA mode + db 025h + db 2 + db 18 ; SPT (good for 1.44MB media) + db 01Bh + db 0FFh + db 06Ch + db 0F6h ; format filler + db 15 + db 8 + + + +;; -------------------------------------------------------- +;; INT 17h handler - Printer service +;; -------------------------------------------------------- + BIOSORG_CHECK 0EFD2h ; fixed WRT preceding code + + jmp int17_handler ; NT floppy boot workaround + ; see @bugref{6481} +int17_handler: + push ds + push es + DO_pusha + C_SETUP + call _int17_function + DO_popa + pop es + pop ds + iret + + + +;; Protected mode IDT descriptor +;; +;; The limit is 0 to cause a shutdown if an exception occurs +;; in protected mode. TODO: Is that what we really want? +;; +;; Set base to F0000 to correspond to beginning of BIOS, +;; in case an IDT is defined later. + +_pmode_IDT: + dw 0 ; limit 15:0 + dw 0 ; base 15:0 + dw 0Fh ; base 23:16 + + +;; Real mode IDT descriptor +;; +;; Set to typical real-mode values. +;; base = 000000 +;; limit = 03ff + +_rmode_IDT: + dw 3FFh ; limit 15:00 + dw 0 ; base 15:00 + dw 0 ; base 23:16 + + +;; +;; INT 1Ch +;; +;; TODO: Why does this need a special handler? +int1c_handler: ;; user timer tick + iret + + + +;; -------------------------------------------------------- +;; INT 10h functions 0-Fh entry point +;; -------------------------------------------------------- + BIOSORG 0F045h, 0F043h +i10f0f_entry: + iret + + +;; -------------------------------------------------------- +;; INT 10h handler - MDA/CGA video +;; -------------------------------------------------------- + BIOSORG 0F065h, 0F063h +int10_handler: + ;; do nothing - assumes VGA + iret + + +;; -------------------------------------------------------- +;; MDA/CGA Video Parameter Table (INT 1Dh) +;; -------------------------------------------------------- + BIOSORG 0F0A4h, 0F0A2h +mdacga_vpt: + + +;; +;; INT 18h - boot failure +;; +int18_handler: + C_SETUP + call _int18_panic_msg + ;; TODO: handle failure better? + hlt + iret + +;; +;; INT 19h - boot service - relocated +;; +int19_relocated: +; If an already booted OS calls int 0x19 to reboot, it is not sufficient +; just to try booting from the configured drives. All BIOS variables and +; interrupt vectors need to be reset, otherwise strange things may happen. +; The approach used is faking a warm reboot (which just skips showing the +; logo), which is a bit more than what we need, but hey, it's fast. + mov bp, sp + mov ax, [bp+2] ; TODO: redundant? address via sp? + cmp ax, BIOSSEG ; check caller's segment + jz bios_initiated_boot + + xor ax, ax + mov ds, ax + mov ax, 1234h + mov ds:[472], ax + jmp post + +bios_initiated_boot: + ;; The C worker function returns the boot drive in bl and + ;; the boot segment in ax. In case of failure, the boot + ;; segment will be zero. + C_SETUP ; TODO: Here? Now? + push bp + mov bp, sp + + ;; 1st boot device + mov ax, 1 + push ax + call _int19_function + inc sp + inc sp + test ax, ax ; if 0, try next device + jnz boot_setup + + ;; 2nd boot device + mov ax, 2 + push ax + call _int19_function + inc sp + inc sp + test ax, ax ; if 0, try next device + jnz boot_setup + + ; 3rd boot device + mov ax, 3 + push ax + call _int19_function + inc sp + inc sp + test ax, ax ; if 0, try next device + jnz boot_setup + + ; 4th boot device + mov ax, 4 + push ax + call _int19_function + inc sp + inc sp + test ax, ax ; if 0, invoke INT 18h + jz int18_handler + +boot_setup: +; TODO: the drive should be in dl already?? +;; mov dl, bl ; tell guest OS what boot drive is +if VBOX_BIOS_CPU lt 80386 + mov [bp], ax + DO_shl ax, 4 + mov [bp+2], ax ; set ip + mov ax, [bp] +else + .386 ; NB: We're getting garbage into high eax bits + shl eax, 4 ; convert seg to ip + mov [bp+2], ax ; set ip + + shr eax, 4 ; get cs back + .286 +endif + and ax, BIOSSEG ; remove what went in ip + mov [bp+4], ax ; set cs + xor ax, ax + mov ds, ax + mov es, ax + mov [bp], ax ; TODO: what's this?! + mov ax, 0AA55h ; set ok flag ; TODO: and this? + + pop bp ; TODO: why'd we just zero it?? + iret ; beam me up scotty + +;; PCI BIOS + +include pcibios.inc +include pirq.inc + + +;; -------------------------------------------------------- +;; INT 12h handler - Memory size +;; -------------------------------------------------------- + BIOSORG 0F841h, 0F83Fh +int12_handler: + ;; Don't touch - fixed size! + sti + push ds + mov ax, 40h + mov ds, ax + mov ax, ds:[13h] + pop ds + iret + + +;; -------------------------------------------------------- +;; INT 11h handler - Equipment list service +;; -------------------------------------------------------- + BIOSORG_CHECK 0F84Dh ; fixed wrt preceding code +int11_handler: + ;; Don't touch - fixed size! + sti + push ds + mov ax, 40h + mov ds, ax + mov ax, ds:[10h] + pop ds + iret + + +;; -------------------------------------------------------- +;; INT 15h handler - System services +;; -------------------------------------------------------- + BIOSORG_CHECK 0F859h ; fixed wrt preceding code +int15_handler: + +if VBOX_BIOS_CPU ge 80286 + cmp ah, 87h + jne not_blkmove + + ;; INT 15h/87h has semi-public interface because software + ;; may use CMOS shutdown status code 9 for its own purposes. + ;; The stack layout has to match. + pusha + push es + push ds + C_SETUP + call _int15_blkmove + pop ds + pop es + popa + iret +not_blkmove: + +endif + + pushf + push ds + push es + C_SETUP +if VBOX_BIOS_CPU ge 80386 + ;; int15_function32 exists in 386+ BIOS only, but INT 15h is + ;; not 386-specific + cmp ah, 0E8h + je int15_handler32 + cmp ah, 0d0h + je int15_handler32 +endif + DO_pusha + cmp ah, 53h ; APM function? + je apm_call + cmp ah, 0C2h ; PS/2 mouse function? + je int15_handler_mouse + + call _int15_function +int15_handler_popa_ret: + DO_popa +if VBOX_BIOS_CPU ge 80386 +int15_handler32_ret: +endif + pop es + pop ds + popf + jmp iret_modify_cf + +apm_call: + call _apm_function + jmp int15_handler_popa_ret + +int15_handler_mouse: + call _int15_function_mouse + jmp int15_handler_popa_ret + +if VBOX_BIOS_CPU ge 80386 +int15_handler32: + ;; need to save/restore 32-bit registers + .386 + pushad + call _int15_function32 + popad + .286 + jmp int15_handler32_ret +endif + +;; +;; Perform an IRET but retain the current carry flag value +;; +iret_modify_cf: + jc carry_set + push bp + mov bp, sp + and byte ptr [bp + 6], 0FEh + or word ptr [bp + 6], 0200h + pop bp + iret +carry_set: + push bp + mov bp, sp + or word ptr [bp + 6], 0201h + pop bp + iret + +;; +;; INT 74h handler - PS/2 mouse (IRQ 12) +;; +int74_handler proc + + sti + DO_pusha + push es + push ds + xor ax, ax + push ax ; placeholder for status + push ax ; placeholder for X + push ax ; placeholder for Y + push ax ; placeholder for Z + push ax ; placeholder for make_far_call bool + C_SETUP + call _int74_function + pop cx ; pop make_far_call flag + jcxz int74_done + + ;; make far call to EBDA:0022 +if VBOX_BIOS_CPU ge 80186 + push 0 +else + xor ax, ax + push ax +endif + pop ds + push ds:[40Eh] + pop ds + call far ptr ds:[22h] +int74_done: + cli + call eoi_both_pics + add sp, 8 ; remove status, X, Y, Z + pop ds + pop es + DO_popa + iret + +int74_handler endp + +int76_handler proc + + ;; record completion in BIOS task complete flag + push ax + push ds + mov ax, 40h + mov ds, ax + mov byte ptr ds:[8Eh], 0FFh + call eoi_both_pics + pop ds + pop ax + iret + +int76_handler endp + + +;; +;; IRQ 8 handler (RTC) +;; +int70_handler: + push es + push ds + DO_pusha + C_SETUP + call _int70_function + DO_popa + pop ds + pop es + iret + + + +if VBOX_BIOS_CPU lt 80386 +; +; We're tight on space down below in the int08_handler, so put +; the 16-bit rollover code here. +; +int08_maybe_rollover: + ja int08_rollover + cmp ax, 00B0h + jb int08_rollover_store + ;; there has been a midnight rollover +int08_rollover: + xor dx, dx + xor ax, ax + + inc byte ptr ds:[70h] ; increment rollover flag +int08_rollover_store: + jmp int08_store_ticks +endif + + +;; -------------------------------------------------------- +;; 8x8 font (first 128 characters) +;; -------------------------------------------------------- + BIOSORG 0FA6Eh, 0FA6Ch +include font8x8.inc + + +;; -------------------------------------------------------- +;; INT 1Ah handler - Time of the day + PCI BIOS +;; -------------------------------------------------------- + BIOSORG_CHECK 0FE6Eh ; fixed wrt preceding table +int1a_handler: +if VBOX_BIOS_CPU ge 80386 + cmp ah, 0B1h + jne int1a_normal + + push es + push ds + C_SETUP + .386 + pushad + call _pci16_function + popad + .286 + pop ds + pop es + iret +endif + +int1a_normal: + push es + push ds + DO_pusha + C_SETUP +int1a_callfunction: + call _int1a_function + DO_popa + pop ds + pop es + iret + + +;; -------------------------------------------------------- +;; Timer tick - IRQ 0 handler +;; -------------------------------------------------------- + BIOSORG 0FEA5h, 0FEA3h +int08_handler: +if VBOX_BIOS_CPU ge 80386 + .386 + sti + push eax +else + sti + push ax +endif + push ds + push dx + mov ax, 40h + mov ds, ax + +if VBOX_BIOS_CPU ge 80386 + mov eax, ds:[6Ch] ; get ticks dword + inc eax +else + mov ax, ds:[6Ch] ; get ticks dword + mov dx, ds:[6Ch+2] + inc ax ; inc+jz+inc saves two bytes over add+adc. + jnz int08_compare + inc dx +int08_compare: +endif + + ;; compare eax to one day's worth of ticks (at 18.2 Hz) +if VBOX_BIOS_CPU ge 80386 + cmp eax, 1800B0h + jb int08_store_ticks +else + cmp dx, 18h + jb int08_store_ticks + jmp int08_maybe_rollover +endif + +if VBOX_BIOS_CPU ge 80386 + ;; there has been a midnight rollover + xor eax, eax + inc byte ptr ds:[70h] ; increment rollover flag + +int08_store_ticks: + mov ds:[6Ch], eax +else +int08_store_ticks: + mov ds:[6Ch], ax + mov ds:[6Ch+2], dx +endif + + ;; time to turn off floppy drive motor(s)? + mov al, ds:[40h] + or al, al + jz int08_floppy_off + dec al + mov ds:[40h], al + jnz int08_floppy_off + ;; turn motor(s) off + mov dx, 03F2h + in al, dx + and al, 0CFh + out dx, al +int08_floppy_off: + + int 1Ch ; call the user timer handler + + cli + call eoi_master_pic + pop dx + pop ds +if VBOX_BIOS_CPU ge 80386 + pop eax + .286 +else + pop ax +endif + iret + + +;; -------------------------------------------------------- +;; Initial interrupt vector offsets for POST +;; -------------------------------------------------------- + BIOSORG 0FEF3h, 0FEF1h +vector_table: + + + +;; -------------------------------------------------------- +;; BIOS copyright string +;; -------------------------------------------------------- + BIOSORG 0FF00h, 0FEFEh +bios_string: + db BIOS_COPYRIGHT + + +;; -------------------------------------------------------- +;; IRET - default interrupt handler +;; -------------------------------------------------------- + BIOSORG 0FF53h, 0FF51h + +dummy_iret: + iret + + +;; -------------------------------------------------------- +;; INT 05h - Print Screen service +;; -------------------------------------------------------- + BIOSORG_CHECK 0FF54h ; fixed wrt preceding +int05_handler: + ;; Not implemented + iret + +include smidmi.inc + +;; -------------------------------------------------------- +;; Processor reset entry point +;; -------------------------------------------------------- + BIOSORG 0FFF0h, 0FFEEh +cpu_reset: + ;; This is where the CPU starts executing after a reset + jmp far ptr post + + ;; BIOS build date + db BIOS_BUILD_DATE + db 0 ; padding + ;; System model ID + db SYS_MODEL_ID + ;; Checksum byte + db 0FFh + + +BIOSSEG ends + + end + |