From f215e02bf85f68d3a6106c2a1f4f7f063f819064 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:17:27 +0200 Subject: Adding upstream version 7.0.14-dfsg. Signed-off-by: Daniel Baumann --- src/VBox/Devices/PC/BIOS/timepci.c | 334 +++++++++++++++++++++++++++++++++++++ 1 file changed, 334 insertions(+) create mode 100644 src/VBox/Devices/PC/BIOS/timepci.c (limited to 'src/VBox/Devices/PC/BIOS/timepci.c') diff --git a/src/VBox/Devices/PC/BIOS/timepci.c b/src/VBox/Devices/PC/BIOS/timepci.c new file mode 100644 index 00000000..ec812ce1 --- /dev/null +++ b/src/VBox/Devices/PC/BIOS/timepci.c @@ -0,0 +1,334 @@ +/* + * Copyright (C) 2006-2023 Oracle and/or its affiliates. + * + * This file is part of VirtualBox base platform packages, as + * available from https://www.virtualbox.org. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, in version 3 of the + * License. + * + * This program 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 + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see . + * + * SPDX-License-Identifier: GPL-3.0-only + * -------------------------------------------------------------------- + * + * 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 +#include "biosint.h" +#include "inlines.h" + +#if DEBUG_INT1A +# define BX_DEBUG_INT1A(...) BX_DEBUG(__VA_ARGS__) +#else +# define BX_DEBUG_INT1A(...) +#endif + +// for access to RAM area which is used by interrupt vectors +// and BIOS Data Area + +typedef struct { + uint8_t filler1[0x400]; + uint8_t filler2[0x6c]; + uint16_t ticks_low; + uint16_t ticks_high; + uint8_t midnight_flag; +} bios_data_t; + +#define BiosData ((bios_data_t __far *) 0) + +void init_rtc(void) +{ + outb_cmos(0x0a, 0x26); + outb_cmos(0x0b, 0x02); + inb_cmos(0x0c); + inb_cmos(0x0d); +} + +bx_bool rtc_updating(void) +{ + // This function checks to see if the update-in-progress bit + // is set in CMOS Status Register A. If not, it returns 0. + // If it is set, it tries to wait until there is a transition + // to 0, and will return 0 if such a transition occurs. A 1 + // is returned only after timing out. The maximum period + // that this bit should be set is constrained to 244useconds. + // The count I use below guarantees coverage or more than + // this time, with any reasonable IPS setting. + + uint16_t iter; + + iter = 25000; + while (--iter != 0) { + if ( (inb_cmos(0x0a) & 0x80) == 0 ) + return 0; + } + return 1; // update-in-progress never transitioned to 0 +} + + +extern void eoi_both_pics(void); /* in assembly code */ +#pragma aux eoi_both_pics "*"; + +void call_int_4a(void); +#pragma aux call_int_4a = "int 4Ah"; + +void BIOSCALL int70_function(pusha_regs_t regs, uint16_t ds, uint16_t es, iret_addr_t iret_addr) +{ + // INT 70h: IRQ 8 - CMOS RTC interrupt from periodic or alarm modes + uint8_t registerB = 0, registerC = 0; + + // Check which modes are enabled and have occurred. + registerB = inb_cmos( 0xB ); + registerC = inb_cmos( 0xC ); + + if( ( registerB & 0x60 ) != 0 ) { + if( ( registerC & 0x20 ) != 0 ) { + // Handle Alarm Interrupt. + int_enable(); + call_int_4a(); + int_disable(); + } + if( ( registerC & 0x40 ) != 0 ) { + // Handle Periodic Interrupt. + + if( read_byte( 0x40, 0xA0 ) != 0 ) { + // Wait Interval (Int 15, AH=83 or AH=86) active. + uint32_t time; + + time = read_dword( 0x40, 0x9C ); // Time left in microseconds. + if( time < 0x3D1 ) { + // Done waiting. + uint16_t segment, offset; + + segment = read_word( 0x40, 0x98 ); + offset = read_word( 0x40, 0x9A ); + write_byte( 0x40, 0xA0, 0 ); // Turn off status byte. + outb_cmos( 0xB, registerB & 0x37 ); // Clear the Periodic Interrupt. + write_byte( segment, offset, read_byte(segment, offset) | 0x80 ); // Write to specified flag byte. + } else { + // Continue waiting. + time -= 0x3D1; + write_dword( 0x40, 0x9C, time ); + } + } + } + } + eoi_both_pics(); +} + +/// @todo the coding style WRT register access is totally inconsistent +// in the following routines + +void BIOSCALL int1a_function(pusha_regs_t regs, uint16_t ds, uint16_t es, iret_addr_t iret_addr) +{ + uint8_t val8; + + BX_DEBUG_INT1A("int1a: AX=%04x BX=%04x CX=%04x DX=%04x DS=%04x\n", + regs.u.r16.ax, regs.u.r16.bx, regs.u.r16.cx, regs.u.r16.dx, ds); + int_enable(); + + switch (regs.u.r8.ah) { + case 0: // get current clock count + int_disable(); + regs.u.r16.cx = BiosData->ticks_high; + regs.u.r16.dx = BiosData->ticks_low; + regs.u.r8.al = BiosData->midnight_flag; + BiosData->midnight_flag = 0; // reset flag + int_enable(); + // AH already 0 + ClearCF(iret_addr.flags); // OK + break; + + case 1: // Set Current Clock Count + int_disable(); + BiosData->ticks_high = regs.u.r16.cx; + BiosData->ticks_low = regs.u.r16.dx; + BiosData->midnight_flag = 0; // reset flag + int_enable(); + regs.u.r8.ah = 0; + ClearCF(iret_addr.flags); // OK + break; + + case 2: // Read CMOS Time + if (rtc_updating()) { + SetCF(iret_addr.flags); + break; + } + + regs.u.r8.dh = inb_cmos(0x00); // Seconds + regs.u.r8.cl = inb_cmos(0x02); // Minutes + regs.u.r8.ch = inb_cmos(0x04); // Hours + regs.u.r8.dl = inb_cmos(0x0b) & 0x01; // Stat Reg B + regs.u.r8.ah = 0; + regs.u.r8.al = regs.u.r8.ch; + ClearCF(iret_addr.flags); // OK + break; + + case 3: // Set CMOS Time + // Using a debugger, I notice the following masking/setting + // of bits in Status Register B, by setting Reg B to + // a few values and getting its value after INT 1A was called. + // + // try#1 try#2 try#3 + // before 1111 1101 0111 1101 0000 0000 + // after 0110 0010 0110 0010 0000 0010 + // + // Bit4 in try#1 flipped in hardware (forced low) due to bit7=1 + // My assumption: RegB = ((RegB & 01100000b) | 00000010b) + if (rtc_updating()) { + init_rtc(); + // fall through as if an update were not in progress + } + outb_cmos(0x00, regs.u.r8.dh); // Seconds + outb_cmos(0x02, regs.u.r8.cl); // Minutes + outb_cmos(0x04, regs.u.r8.ch); // Hours + // Set Daylight Savings time enabled bit to requested value + val8 = (inb_cmos(0x0b) & 0x60) | 0x02 | (regs.u.r8.dl & 0x01); + // (reg B already selected) + outb_cmos(0x0b, val8); + regs.u.r8.ah = 0; + regs.u.r8.al = val8; // val last written to Reg B + ClearCF(iret_addr.flags); // OK + break; + + case 4: // Read CMOS Date + regs.u.r8.ah = 0; + if (rtc_updating()) { + SetCF(iret_addr.flags); + break; + } + regs.u.r8.cl = inb_cmos(0x09); // Year + regs.u.r8.dh = inb_cmos(0x08); // Month + regs.u.r8.dl = inb_cmos(0x07); // Day of Month + regs.u.r8.ch = inb_cmos(0x32); // Century + regs.u.r8.al = regs.u.r8.ch; + ClearCF(iret_addr.flags); // OK + break; + + case 5: // Set CMOS Date + // Using a debugger, I notice the following masking/setting + // of bits in Status Register B, by setting Reg B to + // a few values and getting its value after INT 1A was called. + // + // try#1 try#2 try#3 try#4 + // before 1111 1101 0111 1101 0000 0010 0000 0000 + // after 0110 1101 0111 1101 0000 0010 0000 0000 + // + // Bit4 in try#1 flipped in hardware (forced low) due to bit7=1 + // My assumption: RegB = (RegB & 01111111b) + if (rtc_updating()) { + init_rtc(); + SetCF(iret_addr.flags); + break; + } + outb_cmos(0x09, regs.u.r8.cl); // Year + outb_cmos(0x08, regs.u.r8.dh); // Month + outb_cmos(0x07, regs.u.r8.dl); // Day of Month + outb_cmos(0x32, regs.u.r8.ch); // Century + val8 = inb_cmos(0x0b) & 0x7f; // clear halt-clock bit + outb_cmos(0x0b, val8); + regs.u.r8.ah = 0; + regs.u.r8.al = val8; // AL = val last written to Reg B + ClearCF(iret_addr.flags); // OK + break; + + case 6: // Set Alarm Time in CMOS + // Using a debugger, I notice the following masking/setting + // of bits in Status Register B, by setting Reg B to + // a few values and getting its value after INT 1A was called. + // + // try#1 try#2 try#3 + // before 1101 1111 0101 1111 0000 0000 + // after 0110 1111 0111 1111 0010 0000 + // + // Bit4 in try#1 flipped in hardware (forced low) due to bit7=1 + // My assumption: RegB = ((RegB & 01111111b) | 00100000b) + val8 = inb_cmos(0x0b); // Get Status Reg B + regs.u.r16.ax = 0; + if (val8 & 0x20) { + // Alarm interrupt enabled already + SetCF(iret_addr.flags); // Error: alarm in use + break; + } + if (rtc_updating()) { + init_rtc(); + // fall through as if an update were not in progress + } + outb_cmos(0x01, regs.u.r8.dh); // Seconds alarm + outb_cmos(0x03, regs.u.r8.cl); // Minutes alarm + outb_cmos(0x05, regs.u.r8.ch); // Hours alarm + outb(0xa1, inb(0xa1) & 0xfe); // enable IRQ 8 + // enable Status Reg B alarm bit, clear halt clock bit + outb_cmos(0x0b, (val8 & 0x7f) | 0x20); + ClearCF(iret_addr.flags); // OK + break; + + case 7: // Turn off Alarm + // Using a debugger, I notice the following masking/setting + // of bits in Status Register B, by setting Reg B to + // a few values and getting its value after INT 1A was called. + // + // try#1 try#2 try#3 try#4 + // before 1111 1101 0111 1101 0010 0000 0010 0010 + // after 0100 0101 0101 0101 0000 0000 0000 0010 + // + // Bit4 in try#1 flipped in hardware (forced low) due to bit7=1 + // My assumption: RegB = (RegB & 01010111b) + val8 = inb_cmos(0x0b); // Get Status Reg B + // clear clock-halt bit, disable alarm bit + outb_cmos(0x0b, val8 & 0x57); // disable alarm bit + regs.u.r8.ah = 0; + regs.u.r8.al = val8; // val last written to Reg B + ClearCF(iret_addr.flags); // OK + break; + + default: + BX_DEBUG_INT1A("int1a: AX=%04x unsupported\n", regs.u.r16.ax); + SetCF(iret_addr.flags); // Unsupported + } +} -- cgit v1.2.3