diff options
Diffstat (limited to 'src/VBox/Devices/PC/BIOS/system.c')
| -rw-r--r-- | src/VBox/Devices/PC/BIOS/system.c | 897 |
1 files changed, 897 insertions, 0 deletions
diff --git a/src/VBox/Devices/PC/BIOS/system.c b/src/VBox/Devices/PC/BIOS/system.c new file mode 100644 index 00000000..f2404af2 --- /dev/null +++ b/src/VBox/Devices/PC/BIOS/system.c @@ -0,0 +1,897 @@ +/* $Id: system.c $ */ +/** @file + * PC BIOS - ??? + */ + +/* + * Copyright (C) 2006-2022 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 <https://www.gnu.org/licenses>. + * + * 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 <iprt/cdefs.h> +#include <stdint.h> +#include "biosint.h" +#include "inlines.h" + +#if DEBUG_INT15 +# define BX_DEBUG_INT15(...) BX_DEBUG(__VA_ARGS__) +#else +# define BX_DEBUG_INT15(...) +#endif + + +#define UNSUPPORTED_FUNCTION 0x86 /* Specific to INT 15h. */ + +#define BIOS_CONFIG_TABLE 0xe6f5 /** @todo configurable? put elsewhere? */ + +#define ACPI_DATA_SIZE 0x00010000L /** @todo configurable? put elsewhere? */ + +extern int pmode_IDT; +extern int rmode_IDT; + +uint16_t read_ss(void); +#pragma aux read_ss = "mov ax, ss" modify exact [ax] nomemory; + +#if VBOX_BIOS_CPU >= 80386 + +/* The 386+ code uses CR0 to switch to/from protected mode. + * Quite straightforward. + */ + +void pm_stack_save(uint16_t cx, uint16_t es, uint16_t si); +#pragma aux pm_stack_save = \ + ".386" \ + "push ds" \ + "push eax" \ + "xor ax, ax" \ + "mov ds, ax" \ + "mov ds:[467h], sp" \ + "mov ds:[469h], ss" \ + parm [cx] [es] [si] modify nomemory; + +/* Uses position independent code to build a far return... because it was + * too hard to figure out how to code the far call in inline assembler. + * + * NB: It would be lovely to do 'add [sp],N' instead of 'pop ax; add ax,M; + * push ax'. Unfortunately the former cannot be encoded, though 'add [esp],N' + * can be on 386 and later -- but it may be unwise to assume that the high + * bits of ESP are all zero. + */ +void pm_enter(void); +#pragma aux pm_enter = \ + ".386p" \ + "lgdt fword ptr es:[si+8]" \ + "lidt fword ptr cs:pmode_IDT" \ + "push 20h" \ + "call pentry" \ + "pentry:" \ + "pop ax" \ + "add ax, 0Eh" \ + "push ax" \ + "mov eax, cr0" \ + "or al, 1" \ + "mov cr0, eax" \ + "retf" \ + "pm_pm:" \ + "mov ax, 10h" \ + "mov ds, ax" \ + "add al, 08h" \ + "mov es, ax" \ + "add al, 10h" \ + "mov ss, ax" \ + modify nomemory; + +/* Restore segment limits to real mode compatible values and + * return to real mode. + */ +void pm_exit(void); +#pragma aux pm_exit = \ + ".386p" \ + "mov ax, 28h" \ + "mov ds, ax" \ + "mov es, ax" \ + "push 0F000h" \ + "call pexit" \ + "pexit:" \ + "pop ax" \ + "add ax, 0Eh" \ + "push ax" \ + "mov eax, cr0" \ + "and al, 0FEh" \ + "mov cr0, eax" \ + "retf" \ + "real_mode:" \ + "lidt fword ptr cs:rmode_IDT" \ + modify nomemory; + +/* Restore stack and reload segment registers in real mode to ensure + * real mode compatible selector+base. + */ +void pm_stack_restore(void); +#pragma aux pm_stack_restore = \ + ".386" \ + "xor ax, ax" \ + "mov ds, ax" \ + "mov es, ax" \ + "lss sp, ds:[467h]" \ + "pop eax" \ + "pop ds" \ + modify nomemory; + +#elif VBOX_BIOS_CPU >= 80286 + +/* The 286 code uses LMSW to switch to protected mode but it has to reset + * the CPU to get back to real mode. Ugly! See return_blkmove in orgs.asm + * for the other matching half. + */ +void pm_stack_save(uint16_t cx, uint16_t es, uint16_t si, uint16_t frame); +#pragma aux pm_stack_save = \ + "xor ax, ax" \ + "mov ds, ax" \ + "mov ds:[467h], bx" \ + "mov ds:[469h], ss" \ + parm [cx] [es] [si] [bx] modify nomemory; + +/* Uses position independent code... because it was too hard to figure + * out how to code the far call in inline assembler. + */ +void pm_enter(void); +#pragma aux pm_enter = \ + ".286p" \ + "lgdt fword ptr es:[si+8]" \ + "lidt fword ptr cs:pmode_IDT" \ + "push 20h" \ + "call pentry" \ + "pentry:" \ + "pop ax" \ + "add ax, 0Eh" \ + "push ax" \ + "smsw ax" \ + "or al, 1" \ + "lmsw ax" \ + "retf" \ + "pm_pm:" \ + "mov ax, 10h" \ + "mov ds, ax" \ + "add al, 08h" \ + "mov es, ax" \ + "add al, 10h" \ + "mov ss, ax" \ + modify nomemory; + +/* Set up shutdown status and reset the CPU. The POST code + * will regain control. Port 80h is written with status. + * Code 9 is written to CMOS shutdown status byte (0Fh). + * CPU is triple faulted. . + */ +void pm_exit(void); +#pragma aux pm_exit = \ + "xor ax, ax" \ + "out 80h, al" \ + "mov al, 0Fh" \ + "out 70h, al" \ + "mov al, 09h" \ + "out 71h, al" \ + ".286p" \ + "lidt fword ptr cs:pmode_IDT" \ + "int 3" \ + modify nomemory; + +/* Dummy. Actually done in return_blkmove. */ +void pm_stack_restore(void); +#pragma aux pm_stack_restore = \ + "rm_return:" \ + modify nomemory; + +#endif + +/* NB: CX is set earlier in pm_stack_save */ +void pm_copy(void); +#pragma aux pm_copy = \ + "xor si, si" \ + "xor di, di" \ + "cld" \ + "rep movsw" \ + modify [si di cx] nomemory; + +/* The pm_switch has a few crucial differences from pm_enter, hence + * it is replicated here. Uses LMSW to avoid trashing high word of eax. + */ +void pm_switch(uint16_t reg_si); +#pragma aux pm_switch = \ + ".286p" \ + "lgdt fword ptr es:[si+08h]" \ + "lidt fword ptr es:[si+10h]" \ + "push 38h" \ + "call pentry" \ + "pentry:" \ + "pop ax" \ + "add ax, 0Eh" \ + "push ax" \ + "smsw ax" \ + "or al, 1" \ + "lmsw ax" \ + "retf" \ + "pm_pm:" \ + "mov ax, 18h" \ + "mov ds, ax" \ + "add al, 08h" \ + "mov es, ax" \ + "add al, 08h" \ + "mov ss, ax" \ + parm [si] modify nomemory; + +/* Return to caller - we do not use IRET because we should not enable + * interrupts. Note that AH must be zero on exit. + * WARNING: Needs to be adapted if calling sequence is modified! + */ +void pm_unwind(uint16_t args); +#pragma aux pm_unwind = \ + ".286" \ + "mov sp, ax" \ + "popa" \ + "add sp, 6" \ + "pop cx" \ + "pop ax" \ + "pop ax" \ + "mov ax, 30h" \ + "push ax" \ + "push cx" \ + "retf" \ + parm [ax] modify nomemory aborts; + +bx_bool set_enable_a20(bx_bool val) +{ + uint8_t oldval; + + // Use PS/2 System Control port A to set A20 enable + + // get current setting first + oldval = inb(0x92); + + // change A20 status + if (val) + outb(0x92, oldval | 0x02); + else + outb(0x92, oldval & 0xfd); + + return((oldval & 0x02) != 0); +} + +/// @todo move elsewhere? +#define AX r.gr.u.r16.ax +#define BX r.gr.u.r16.bx +#define CX r.gr.u.r16.cx +#define DX r.gr.u.r16.dx +#define SI r.gr.u.r16.si +#define DI r.gr.u.r16.di +#define BP r.gr.u.r16.bp +#define SP r.gr.u.r16.sp +#define FLAGS r.fl.u.r16.flags +#define EAX r.gr.u.r32.eax +#define EBX r.gr.u.r32.ebx +#define ECX r.gr.u.r32.ecx +#define EDX r.gr.u.r32.edx +#define ESI r.gr.u.r32.esi +#define EDI r.gr.u.r32.edi +#define ES r.es + + +void BIOSCALL int15_function(sys_regs_t r) +{ + uint16_t bRegister; + uint8_t irqDisable; + + BX_DEBUG_INT15("int15 AX=%04x\n",AX); + + switch (GET_AH()) { + case 0x00: /* assorted functions */ + if (GET_AL() != 0xc0) + goto undecoded; + /* GRUB calls int15 with ax=0x00c0 to get the ROM configuration table, + * which we don't support, but logging that event is annoying. In fact + * it is likely that they just misread some specs, because there is a + * int15 BIOS function AH=0xc0 which sounds quite similar to what GRUB + * wants to achieve. */ + SET_CF(); + SET_AH(UNSUPPORTED_FUNCTION); + break; + case 0x24: /* A20 Control */ + switch (GET_AL()) { + case 0x00: + set_enable_a20(0); + CLEAR_CF(); + SET_AH(0); + break; + case 0x01: + set_enable_a20(1); + CLEAR_CF(); + SET_AH(0); + break; + case 0x02: + SET_AL( (inb(0x92) >> 1) & 0x01 ); + CLEAR_CF(); + SET_AH(0); + break; + case 0x03: + CLEAR_CF(); + SET_AH(0); + BX = 3; + break; + default: + BX_INFO("int15: Func 24h, subfunc %02xh, A20 gate control not supported\n", (unsigned) GET_AL()); + SET_CF(); + SET_AH(UNSUPPORTED_FUNCTION); + } + break; + + /* These are here just to avoid warnings being logged. */ + case 0x22: /* Locate ROM BASIC (tough when we don't have any.) */ + case 0x41: /* PC Convertible, wait for external events. */ + case 0xC7: /* PS/2, get memory map. */ + SET_CF(); + SET_AH(UNSUPPORTED_FUNCTION); + break; + + /// @todo Why does this need special handling? All we need is to set CF + // but not handle this as an unknown function (regardless of CPU type). + case 0x4f: + /* keyboard intercept */ +#if VBOX_BIOS_CPU >= 80286 + // nop +#else + SET_AH(UNSUPPORTED_FUNCTION); +#endif + SET_CF(); + break; + + case 0x52: // removable media eject + CLEAR_CF(); + SET_AH(0); // "ok ejection may proceed" + break; + + case 0x83: { + if( GET_AL() == 0 ) { + // Set Interval requested. + if( ( read_byte( 0x40, 0xA0 ) & 1 ) == 0 ) { + // Interval not already set. + write_byte( 0x40, 0xA0, 1 ); // Set status byte. + write_word( 0x40, 0x98, ES ); // Byte location, segment + write_word( 0x40, 0x9A, BX ); // Byte location, offset + write_word( 0x40, 0x9C, DX ); // Low word, delay + write_word( 0x40, 0x9E, CX ); // High word, delay. + CLEAR_CF( ); + // Unmask IRQ8 so INT70 will get through. + irqDisable = inb( 0xA1 ); + outb( 0xA1, irqDisable & 0xFE ); + bRegister = inb_cmos( 0xB ); + // Turn on the Periodic Interrupt timer + outb_cmos( 0xB, bRegister | 0x40 ); + } else { + // Interval already set. + BX_DEBUG_INT15("int15: Func 83h, failed, already waiting.\n" ); + SET_CF(); // AH is left unmodified + } + } else if( GET_AL() == 1 ) { + // Clear Interval requested + write_byte( 0x40, 0xA0, 0 ); // Clear status byte + CLEAR_CF( ); + bRegister = inb_cmos( 0xB ); + outb_cmos( 0xB, bRegister & ~0x40 ); // Turn off the Periodic Interrupt timer + } else { + BX_DEBUG_INT15("int15: Func 83h, failed.\n" ); + SET_CF(); + SET_AH(UNSUPPORTED_FUNCTION); + SET_AL(GET_AL() - 1); + } + + break; + } + + case 0x86: + // Set Interval requested. + if( ( read_byte( 0x40, 0xA0 ) & 1 ) == 0 ) { + // Interval not already set. + write_byte( 0x40, 0xA0, 1 ); // Set status byte. + write_word( 0x40, 0x98, 0x40 ); // Byte location, segment + write_word( 0x40, 0x9A, 0xA0 ); // Byte location, offset + write_word( 0x40, 0x9C, DX ); // Low word, delay + write_word( 0x40, 0x9E, CX ); // High word, delay. + // Unmask IRQ8 so INT70 will get through. + irqDisable = inb( 0xA1 ); + outb( 0xA1, irqDisable & 0xFE ); + bRegister = inb_cmos( 0xB ); + // Turn on the Periodic Interrupt timer + outb_cmos( 0xB, bRegister | 0x40 ); + // Now wait until timer interrupt says wait is done. + int_enable(); + do { + halt(); + bRegister = read_byte( 0x40, 0xA0 ); + } + while( !(bRegister & 0x80) ); + write_byte( 0x40, 0xA0, 0 ); // Deactivate wait. + CLEAR_CF( ); + } else { + // Interval already set. + BX_DEBUG_INT15("int15: Func 86h, failed, already waiting.\n" ); + SET_CF(); // AH is left unmodified + } + break; + + case 0x88: + // Get the amount of extended memory (above 1M) +#if VBOX_BIOS_CPU >= 80286 + AX = get_cmos_word(0x30 /*, 0x31*/); + +#if VBOX_BIOS_CPU >= 80386 + // According to Ralf Brown's interrupt the limit should be 15M, + // but real machines mostly return max. 63M. + if(AX > 0xffc0) + AX = 0xffc0; +#else + // An AT compatible cannot have more than 15M extended memory. + // If more is reported, some software (e.g. Windows 3.1) gets + // quite upset. + if(AX > 0x3c00) + AX = 0x3c00; +#endif + + CLEAR_CF(); +#else + SET_AH(UNSUPPORTED_FUNCTION); + SET_CF(); +#endif + break; + + case 0x89: + // Switch to Protected Mode. + // ES:DI points to user-supplied GDT + // BH/BL contains starting interrupt numbers for PIC0/PIC1 + // This subfunction does not return! + + // turn off interrupts + int_disable(); /// @todo aren't they off already? + + set_enable_a20(1); // enable A20 line; we're supposed to fail if that fails + + // Initialize CS descriptor for BIOS + write_word(ES, SI+0x38+0, 0xffff);// limit 15:00 = normal 64K limit + write_word(ES, SI+0x38+2, 0x0000);// base 15:00 + write_byte(ES, SI+0x38+4, 0x000f);// base 23:16 (hardcoded to f000:0000) + write_byte(ES, SI+0x38+5, 0x9b); // access + write_word(ES, SI+0x38+6, 0x0000);// base 31:24/reserved/limit 19:16 + + /* Reprogram the PICs. */ + outb(PIC_MASTER, PIC_CMD_INIT); + outb(PIC_SLAVE, PIC_CMD_INIT); + outb(PIC_MASTER + 1, GET_BH()); + outb(PIC_SLAVE + 1, GET_BL()); + outb(PIC_MASTER + 1, 4); + outb(PIC_SLAVE + 1, 2); + outb(PIC_MASTER + 1, 1); + outb(PIC_SLAVE + 1, 1); + /* Mask all IRQs, user must re-enable. */ + outb(PIC_MASTER_MASK, 0xff); + outb(PIC_SLAVE_MASK, 0xff); + + pm_switch(SI); + pm_unwind((uint16_t)&r); + + break; + + case 0x90: + /* Device busy interrupt. Called by Int 16h when no key available */ + break; + + case 0x91: + /* Interrupt complete. Called by Int 16h when key becomes available */ + break; + + case 0xbf: + BX_INFO("*** int 15h function AH=bf not yet supported!\n"); + SET_CF(); + SET_AH(UNSUPPORTED_FUNCTION); + break; + + case 0xC0: + CLEAR_CF(); + SET_AH(0); + BX = BIOS_CONFIG_TABLE; + ES = 0xF000; + break; + + case 0xc1: + ES = read_word(0x0040, 0x000E); + CLEAR_CF(); + break; + + case 0xd8: + bios_printf(BIOS_PRINTF_DEBUG, "EISA BIOS not present\n"); + SET_CF(); + SET_AH(UNSUPPORTED_FUNCTION); + break; + + /* Make the BIOS warning for pretty much every Linux kernel start + * disappear - it calls with ax=0xe980 to figure out SMI info. */ + case 0xe9: /* SMI functions (SpeedStep and similar things) */ + SET_CF(); + SET_AH(UNSUPPORTED_FUNCTION); + break; + case 0xec: /* AMD64 target operating mode callback */ + if (GET_AL() != 0) + goto undecoded; + SET_AH(0); + if (GET_BL() >= 1 && GET_BL() <= 3) + CLEAR_CF(); /* Accepted value. */ + else + SET_CF(); /* Reserved, error. */ + break; +undecoded: + default: + BX_INFO("*** int 15h function AX=%04x, BX=%04x not yet supported!\n", + (unsigned) AX, (unsigned) BX); + SET_CF(); + SET_AH(UNSUPPORTED_FUNCTION); + break; + } +} + +#if VBOX_BIOS_CPU >= 80386 + +typedef struct { + uint32_t start; + uint32_t xstart; + uint32_t len; + uint32_t xlen; + uint32_t type; +} mem_range_t; + +static void set_e820_range_len(uint16_t reg_ES, uint16_t reg_DI, uint32_t start, uint32_t len, uint8_t type) +{ + mem_range_t __far *fpRange = reg_ES :> (mem_range_t *)reg_DI; + fpRange->start = start; + fpRange->len = len; + fpRange->type = type; + fpRange->xlen = 0; + fpRange->xstart = 0; +} + +#define set_e820_range_end(reg_ES, reg_DI, start, end, type) set_e820_range_len(reg_ES, reg_DI, start, end - start, type) + +static void set_e820_range_above_4g(uint16_t reg_ES, uint16_t reg_DI, uint16_t c64k_above_4G_low, uint16_t c64k_above_4G_high) +{ + mem_range_t __far *fpRange = reg_ES :> (mem_range_t *)reg_DI; + fpRange->start = 0; /* Starts at 4G, so low start address dword is zero */ + fpRange->xstart = 1; /* And the high start dword is 1. */ + fpRange->len = (uint32_t)c64k_above_4G_low << 16; + fpRange->xlen = c64k_above_4G_high; + fpRange->type = 1; /* type is usable */ +} + +void BIOSCALL int15_function32(sys32_regs_t r) +{ + BX_DEBUG_INT15("int15 AX=%04x\n",AX); + + switch (GET_AH()) { + case 0xd0: + if (GET_AL() != 0x4f) + goto int15_unimplemented; + if (EBX == 0x50524f43 && ECX == 0x4d4f4445 && ESI == 0 && EDI == 0) + { + CLEAR_CF(); + ESI = EBX; + EDI = ECX; + EAX = 0x49413332; + } + else + goto int15_unimplemented; + break; + + case 0xe8: + switch(GET_AL()) { + case 0x20: // coded by osmaker aka K.J. + if(EDX == 0x534D4150) { + uint32_t extended_memory_size; // 64bits long + uint16_t c64k_above_4G_low; + uint16_t c64k_above_4G_high; +#ifdef BIOS_WITH_MCFG_E820 + uint32_t mcfgStart, mcfgSize; +#endif + + /* Go for the amount of memory above 16MB first. */ + extended_memory_size = get_cmos_word(0x34 /*, 0x35*/); + if (extended_memory_size > 0) + { + extended_memory_size += _16M / _64K; + extended_memory_size <<= 16; + } + else + { + /* No memory above 16MB, query memory above 1MB ASSUMING we have at least 1MB. */ + extended_memory_size = get_cmos_word(0x30 /*, 0x31*/); + extended_memory_size += _1M / _1K; + extended_memory_size *= _1K; + } + + /* This is the amount of memory above 4GB measured in 64KB units. + Note! 0x65 can be used when we need to go beyond 255 TiB */ + c64k_above_4G_low = get_cmos_word(0x61 /*, 0x62*/); + c64k_above_4G_high = get_cmos_word(0x63 /*, 0x64*/); + +#ifdef BIOS_WITH_MCFG_E820 /** @todo Actually implement the mcfg reporting. */ + mcfgStart = 0; + mcfgSize = 0; +#endif + switch (BX) + { + case 0: + set_e820_range_end(ES, DI, 0x0000000L, 0x0009fc00L, 1); + EBX = 1; + break; + case 1: + set_e820_range_end(ES, DI, 0x0009fc00L, 0x000a0000L, 2); + EBX = 2; + break; + case 2: + /* Mark the BIOS as reserved. VBox doesn't currently + * use the 0xe0000-0xeffff area. It does use the + * 0xd0000-0xdffff area for the BIOS logo, but it's + * not worth marking it as reserved. (this is not + * true anymore because the VGA adapter handles the logo stuff) + * The whole 0xe0000-0xfffff can be used for the BIOS. + * Note that various + * Windows versions don't accept (read: in debug builds + * they trigger the "Too many similar traps" assertion) + * a single reserved range from 0xd0000 to 0xffffff. + * A 128K area starting from 0xd0000 works. */ + set_e820_range_end(ES, DI, 0x000f0000L, 0x00100000L, 2); + EBX = 3; + break; + case 3: + set_e820_range_end(ES, DI, 0x00100000L, extended_memory_size - ACPI_DATA_SIZE, 1); + EBX = 4; + break; + case 4: + set_e820_range_len(ES, DI, extended_memory_size - ACPI_DATA_SIZE, ACPI_DATA_SIZE, 3); // ACPI RAM + EBX = 5; + break; + case 5: + set_e820_range_len(ES, DI, 0xfec00000, 0x1000, 2); // I/O APIC + EBX = 6; + break; + case 6: + set_e820_range_len(ES, DI, 0xfee00000, 0x1000, 2); // Local APIC + EBX = 7; + break; + case 7: + /* 256KB BIOS area at the end of 4 GB */ + set_e820_range_len(ES, DI, 0xfffc0000L, 0x40000, 2); +#ifdef BIOS_WITH_MCFG_E820 + if (mcfgStart != 0) + EBX = 8; + else +#endif + if (c64k_above_4G_low || c64k_above_4G_high) + EBX = 9; + else + EBX = 0; + break; +#ifdef BIOS_WITH_MCFG_E820 + case 8: + /* PCI MMIO config space (MCFG) */ + set_e820_range_len(ES, DI, mcfgStart, mcfgSize, 2); + if (c64k_above_4G_low || c64k_above_4G_high) + EBX = 9; + else + EBX = 0; + break; +#endif + case 9: + /* Mapping of memory above 4 GB if present. */ + if (c64k_above_4G_low || c64k_above_4G_high) + { + set_e820_range_above_4g(ES, DI, c64k_above_4G_low, c64k_above_4G_high); + EBX = 0; + break; + } + /* fall thru */ + default: /* AX=E820, DX=534D4150, BX unrecognized */ + goto int15_unimplemented; + break; + } + EAX = 0x534D4150; + ECX = 0x14; + CLEAR_CF(); + } else { + // if DX != 0x534D4150) + goto int15_unimplemented; + } + break; + + case 0x01: + // do we have any reason to fail here ? + CLEAR_CF(); + + // my real system sets ax and bx to 0 + // this is confirmed by Ralph Brown list + // but syslinux v1.48 is known to behave + // strangely if ax is set to 0 + // regs.u.r16.ax = 0; + // regs.u.r16.bx = 0; + + // Get the amount of extended memory (above 1M) + CX = get_cmos_word(0x30 /*, 0x31*/); + + // limit to 15M + if(CX > 0x3c00) + CX = 0x3c00; + + // Get the amount of extended memory above 16M in 64k blocks + DX = get_cmos_word(0x34 /*, 0x35*/); + + // Set configured memory equal to extended memory + AX = CX; + BX = DX; + break; + default: /* AH=0xE8?? but not implemented */ + goto int15_unimplemented; + } + break; + int15_unimplemented: + // fall into the default case + default: + BX_INFO("*** int 15h function AX=%04x, BX=%04x not yet supported!\n", + (unsigned) AX, (unsigned) BX); + SET_CF(); + SET_AL(UNSUPPORTED_FUNCTION); + break; + } +} +#endif /* VBOX_BIOS_CPU >= 80386 */ + +#if VBOX_BIOS_CPU >= 80286 + +#undef FLAGS +#define FLAGS r.ra.flags.u.r16.flags + +/* Function 0x87 handled separately due to specific stack layout requirements. */ +void BIOSCALL int15_blkmove(disk_regs_t r) +{ + uint16_t base15_00; + uint8_t base23_16; + uint16_t ss; + + // +++ should probably have descriptor checks + // +++ should have exception handlers + + // turn off interrupts + int_disable(); /// @todo aren't they disabled already? + + set_enable_a20(1); // enable A20 line + + // 128K max of transfer on 386+ ??? + // source == destination ??? + + // ES:SI points to descriptor table + // offset use initially comments + // ============================================== + // 00..07 Unused zeros Null descriptor + // 08..0f scratch zeros work area used by BIOS + // 10..17 source ssssssss source of data + // 18..1f dest dddddddd destination of data + // 20..27 CS zeros filled in by BIOS + // 28..2f SS zeros filled in by BIOS + + //es:si + //eeee0 + //0ssss + //----- + + // check for access rights of source & dest here + + // Initialize GDT descriptor + base15_00 = (ES << 4) + SI; + base23_16 = ES >> 12; + if (base15_00 < (ES<<4)) + base23_16++; + write_word(ES, SI+0x08+0, 47); // limit 15:00 = 6 * 8bytes/descriptor + write_word(ES, SI+0x08+2, base15_00);// base 15:00 + write_byte(ES, SI+0x08+4, base23_16);// base 23:16 + write_byte(ES, SI+0x08+5, 0x93); // access + write_word(ES, SI+0x08+6, 0x0000); // base 31:24/reserved/limit 19:16 + + // Initialize CS descriptor + write_word(ES, SI+0x20+0, 0xffff);// limit 15:00 = normal 64K limit + write_word(ES, SI+0x20+2, 0x0000);// base 15:00 + write_byte(ES, SI+0x20+4, 0x000f);// base 23:16 + write_byte(ES, SI+0x20+5, 0x9b); // access + write_word(ES, SI+0x20+6, 0x0000);// base 31:24/reserved/limit 19:16 + + // Initialize SS descriptor + ss = read_ss(); + base15_00 = ss << 4; + base23_16 = ss >> 12; + write_word(ES, SI+0x28+0, 0xffff); // limit 15:00 = normal 64K limit + write_word(ES, SI+0x28+2, base15_00);// base 15:00 + write_byte(ES, SI+0x28+4, base23_16);// base 23:16 + write_byte(ES, SI+0x28+5, 0x93); // access + write_word(ES, SI+0x28+6, 0x0000); // base 31:24/reserved/limit 19:16 + +#if VBOX_BIOS_CPU >= 80386 + /* Not taking the address of the parameter allows the code generator + * produce slightly better code for some unknown reason. + */ + pm_stack_save(CX, ES, SI); +#else + pm_stack_save(CX, ES, SI, FP_OFF(&r)); +#endif + pm_enter(); + pm_copy(); + pm_exit(); + pm_stack_restore(); + + set_enable_a20(0); // unconditionally disable A20 line + + // turn interrupts back on + int_enable(); + + SET_AH(0); + CLEAR_CF(); +} +#endif /* VBOX_BIOS_CPU >= 80286 */ |