X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=src%2Fpost.c;h=5985a570bb37c2e909f56946772919793d567aa7;hb=9f4e1d9ad54ceb4876c4457907766799ab15f1a3;hp=3fcc25126bb9d030a570a251760f40487a5cc60a;hpb=ee2fd7a5880605b1111fb6efa4737d8c78c5d646;p=seabios.git

diff --git a/src/post.c b/src/post.c
index 3fcc251..5985a57 100644
--- a/src/post.c
+++ b/src/post.c
@@ -3,586 +3,223 @@
 // Copyright (C) 2008  Kevin O'Connor <kevin@koconnor.net>
 // Copyright (C) 2002  MandrakeSoft S.A.
 //
-// This file may be distributed under the terms of the GNU GPLv3 license.
+// This file may be distributed under the terms of the GNU LGPLv3 license.
 
 #include "ioport.h" // PORT_*
-#include "../out/rom16.offset.auto.h" // OFFSET_*
 #include "config.h" // CONFIG_*
 #include "cmos.h" // CMOS_*
 #include "util.h" // memset
 #include "biosvar.h" // struct bios_data_area_s
+#include "disk.h" // floppy_drive_setup
+#include "memmap.h" // add_e820
+#include "pic.h" // pic_setup
+#include "pci.h" // create_pirtable
+#include "acpi.h" // acpi_bios_init
+#include "bregs.h" // struct bregs
+#include "boot.h" // IPL
 
-#define bda ((struct bios_data_area_s *)0)
-#define ebda ((struct extended_bios_data_area_s *)(EBDA_SEG<<4))
-#define ipl ((struct ipl_s *)(IPL_SEG<<4))
-
-static u8
-checksum(u8 *p, u32 len)
+void
+__set_irq(int vector, void *loc)
 {
-    u32 i;
-    u8 sum = 0;
-    for (i=0; i<len; i++)
-        sum += p[i];
-    return sum;
+    SET_IVT(vector, SEG_BIOS, (u32)loc - BUILD_BIOS_ADDR);
 }
 
+#define set_irq(vector, func) do {              \
+        extern void func (void);                \
+        __set_irq(vector, func);                \
+    } while (0)
+
 static void
-init_bda()
+init_ivt()
 {
-    memset(bda, 0, sizeof(*bda));
+    dprintf(3, "init ivt\n");
 
+    // Initialize all vectors to the default handler.
     int i;
-    for (i=0; i<256; i++) {
-        bda->ivecs[i].seg = 0xf000;
-        bda->ivecs[i].offset = OFFSET_dummy_iret_handler;
-    }
+    for (i=0; i<256; i++)
+        set_irq(i, entry_iret_official);
+
+    // Initialize all hw vectors to a default hw handler.
+    for (i=0x08; i<=0x0f; i++)
+        set_irq(i, entry_hwpic1);
+    for (i=0x70; i<=0x77; i++)
+        set_irq(i, entry_hwpic2);
+
+    // Initialize software handlers.
+    set_irq(0x10, entry_10);
+    set_irq(0x11, entry_11_official);
+    set_irq(0x12, entry_12_official);
+    set_irq(0x13, entry_13_official);
+    set_irq(0x14, entry_14);
+    set_irq(0x15, entry_15);
+    set_irq(0x16, entry_16);
+    set_irq(0x17, entry_17);
+    set_irq(0x18, entry_18);
+    set_irq(0x19, entry_19_official);
+    set_irq(0x1a, entry_1a);
+    set_irq(0x40, entry_40);
 
-    bda->mem_size_kb = BASE_MEM_IN_K;
-}
-
-static void
-init_handlers()
-{
     // set vector 0x79 to zero
     // this is used by 'gardian angel' protection system
-    bda->ivecs[0x79].seg = 0;
-    bda->ivecs[0x79].offset = 0;
-
-    bda->ivecs[0x40].offset = OFFSET_entry_40;
-    bda->ivecs[0x0e].offset = OFFSET_entry_0e;
-    bda->ivecs[0x13].offset = OFFSET_entry_13;
-    bda->ivecs[0x76].offset = OFFSET_entry_76;
-    bda->ivecs[0x17].offset = OFFSET_entry_17;
-    bda->ivecs[0x18].offset = OFFSET_entry_18;
-    bda->ivecs[0x19].offset = OFFSET_entry_19;
-    bda->ivecs[0x1c].offset = OFFSET_entry_1c;
-    bda->ivecs[0x12].offset = OFFSET_entry_12;
-    bda->ivecs[0x11].offset = OFFSET_entry_11;
-    bda->ivecs[0x15].offset = OFFSET_entry_15;
-    bda->ivecs[0x08].offset = OFFSET_entry_08;
-    bda->ivecs[0x09].offset = OFFSET_entry_09;
-    bda->ivecs[0x16].offset = OFFSET_entry_16;
-    bda->ivecs[0x14].offset = OFFSET_entry_14;
-    bda->ivecs[0x1a].offset = OFFSET_entry_1a;
-    bda->ivecs[0x70].offset = OFFSET_entry_70;
-    bda->ivecs[0x74].offset = OFFSET_entry_74;
-    bda->ivecs[0x75].offset = OFFSET_entry_75;
-    bda->ivecs[0x10].offset = OFFSET_entry_10;
-}
-
-static void
-init_ebda()
-{
-    memset(ebda, 0, sizeof(*ebda));
-    ebda->size = EBDA_SIZE;
-    bda->ebda_seg = EBDA_SEG;
-    bda->ivecs[0x41].seg = EBDA_SEG;
-    bda->ivecs[0x41].offset = offsetof(struct extended_bios_data_area_s, fdpt0);
-    bda->ivecs[0x46].seg = EBDA_SEG;
-    bda->ivecs[0x41].offset = offsetof(struct extended_bios_data_area_s, fdpt1);
-}
-
-static void
-pit_setup()
-{
-    // timer0: binary count, 16bit count, mode 2
-    outb(0x34, PORT_PIT_MODE);
-    // maximum count of 0000H = 18.2Hz
-    outb(0x0, PORT_PIT_COUNTER0);
-    outb(0x0, PORT_PIT_COUNTER0);
-}
-
-//--------------------------------------------------------------------------
-// keyboard_panic
-//--------------------------------------------------------------------------
-static void
-keyboard_panic(u16 status)
-{
-  // If you're getting a 993 keyboard panic here,
-  // please see the comment in keyboard_init
-
-  BX_PANIC("Keyboard error:%u\n",status);
-}
-
-static void
-kbd_wait(u8 mask, u8 code)
-{
-    u16 max = 0xffff;
-    while ( ((inb(PORT_PS2_STATUS) & mask) == 0) && (--max>0) )
-        outb(code, PORT_DIAG);
-    if (!max)
-        keyboard_panic(code);
-}
-
-static inline void kbd_flush(u8 code) {
-    kbd_wait(0x02, code);
-}
-static inline void kbd_waitdata(u8 code) {
-    kbd_wait(0x01, code);
-}
-
-//--------------------------------------------------------------------------
-// keyboard_init
-//--------------------------------------------------------------------------
-// this file is based on LinuxBIOS implementation of keyboard.c
-// could convert to #asm to gain space
-static void
-keyboard_init()
-{
-    /* ------------------- Flush buffers ------------------------*/
-    /* Wait until buffer is empty */
-    kbd_flush(0x00);
-
-    /* flush incoming keys */
-    u16 max=0x2000;
-    while (--max > 0) {
-        outb(0x00, PORT_DIAG);
-        if (inb(PORT_PS2_STATUS) & 0x01) {
-            inb(PORT_PS2_DATA);
-            max = 0x2000;
-            }
-        }
-
-    // Due to timer issues, and if the IPS setting is > 15000000,
-    // the incoming keys might not be flushed here. That will
-    // cause a panic a few lines below.  See sourceforge bug report :
-    // [ 642031 ] FATAL: Keyboard RESET error:993
+    SET_IVT(0x79, 0, 0);
 
-    /* ------------------- controller side ----------------------*/
-    /* send cmd = 0xAA, self test 8042 */
-    outb(0xaa, PORT_PS2_STATUS);
-
-    kbd_flush(0x00);
-    kbd_waitdata(0x01);
-
-    /* read self-test result, 0x55 should be returned from 0x60 */
-    if (inb(PORT_PS2_DATA) != 0x55)
-        keyboard_panic(991);
-
-    /* send cmd = 0xAB, keyboard interface test */
-    outb(0xab, PORT_PS2_STATUS);
-
-    kbd_flush(0x10);
-    kbd_waitdata(0x11);
-
-    /* read keyboard interface test result, */
-    /* 0x00 should be returned form 0x60 */
-    if (inb(PORT_PS2_DATA) != 0x00)
-        keyboard_panic(992);
-
-    /* Enable Keyboard clock */
-    outb(0xae, PORT_PS2_STATUS);
-    outb(0xa8, PORT_PS2_STATUS);
-
-    /* ------------------- keyboard side ------------------------*/
-    /* reset kerboard and self test  (keyboard side) */
-    outb(0xff, PORT_PS2_DATA);
-
-    kbd_flush(0x20);
-    kbd_waitdata(0x21);
-
-    /* keyboard should return ACK */
-    if (inb(PORT_PS2_DATA) != 0xfa)
-        keyboard_panic(993);
-
-    kbd_waitdata(0x31);
-
-    if (inb(PORT_PS2_DATA) != 0xaa)
-        keyboard_panic(994);
-
-    /* Disable keyboard */
-    outb(0xf5, PORT_PS2_DATA);
-
-    kbd_flush(0x40);
-    kbd_waitdata(0x41);
-
-    /* keyboard should return ACK */
-    if (inb(PORT_PS2_DATA) != 0xfa)
-        keyboard_panic(995);
-
-    /* Write Keyboard Mode */
-    outb(0x60, PORT_PS2_STATUS);
-
-    kbd_flush(0x50);
-
-    /* send cmd: scan code convert, disable mouse, enable IRQ 1 */
-    outb(0x61, PORT_PS2_DATA);
-
-    kbd_flush(0x60);
-
-    /* Enable keyboard */
-    outb(0xf4, PORT_PS2_DATA);
-
-    kbd_flush(0x70);
-    kbd_waitdata(0x71);
-
-    /* keyboard should return ACK */
-    if (inb(PORT_PS2_DATA) != 0xfa)
-        keyboard_panic(996);
-
-    outb(0x77, PORT_DIAG);
-}
-
-static void
-kbd_setup()
-{
-    bda->kbd_mode = 0x10;
-    bda->kbd_buf_head = bda->kbd_buf_tail = bda->kbd_buf_start_offset
-        = offsetof(struct bios_data_area_s, kbd_buf) - 0x400;
-    bda->kbd_buf_end_offset
-        = (offsetof(struct bios_data_area_s, kbd_buf[sizeof(bda->kbd_buf)])
-           - 0x400);
-    keyboard_init();
-
-    // mov CMOS Equipment Byte to BDA Equipment Word
-    u16 eqb = bda->equipment_list_flags;
-    bda->equipment_list_flags = (eqb & 0xff00) | inb_cmos(CMOS_EQUIPMENT_INFO);
-}
-
-static u16
-detect_parport(u16 port, u8 timeout, u8 count)
-{
-    // clear input mode
-    outb(inb(port+2) & 0xdf, port+2);
-
-    outb(0xaa, port);
-    if (inb(port) != 0xaa)
-        // Not present
-        return 0;
-    bda->port_lpt[count] = port;
-    bda->lpt_timeout[count] = timeout;
-    return 1;
+    __set_irq(0x1E, &diskette_param_table2);
 }
 
 static void
-lpt_setup()
+init_bda()
 {
-    u16 count = 0;
-    count += detect_parport(0x378, 0x14, count);
-    count += detect_parport(0x278, 0x14, count);
+    dprintf(3, "init bda\n");
 
-    // Equipment word bits 14..15 determing # parallel ports
-    u16 eqb = bda->equipment_list_flags;
-    bda->equipment_list_flags = (eqb & 0x3fff) | (count << 14);
-}
+    struct bios_data_area_s *bda = MAKE_FLATPTR(SEG_BDA, 0);
+    memset(bda, 0, sizeof(*bda));
 
-static u16
-detect_serial(u16 port, u8 timeout, u8 count)
-{
-    outb(0x02, port+1);
-    if (inb(port+1) != 0x02)
-        return 0;
-    if (inb(port+2) != 0x02)
-        return 0;
-    outb(0x00, port+1);
-    bda->port_com[count] = port;
-    bda->com_timeout[count] = timeout;
-    return 1;
-}
+    int esize = DIV_ROUND_UP(sizeof(struct extended_bios_data_area_s), 1024);
+    SET_BDA(mem_size_kb, 640 - esize);
+    u16 eseg = FLATPTR_TO_SEG((640 - esize) * 1024);
+    SET_BDA(ebda_seg, eseg);
 
-static void
-serial_setup()
-{
-    u16 count = 0;
-    count += detect_serial(0x3f8, 0x0a, count);
-    count += detect_serial(0x2f8, 0x0a, count);
-    count += detect_serial(0x3e8, 0x0a, count);
-    count += detect_serial(0x2e8, 0x0a, count);
-
-    // Equipment word bits 9..11 determing # serial ports
-    u16 eqb = bda->equipment_list_flags;
-    bda->equipment_list_flags = (eqb & 0xf1ff) | (count << 9);
-}
-
-static u32
-bcd2bin(u8 val)
-{
-    return (val & 0xf) + ((val >> 4) * 10);
-}
+    struct extended_bios_data_area_s *ebda = get_ebda_ptr();
+    memset(ebda, 0, sizeof(*ebda));
+    ebda->size = esize;
+    SET_IVT(0x41, eseg, offsetof(struct extended_bios_data_area_s, fdpt[0]));
+    SET_IVT(0x46, eseg, offsetof(struct extended_bios_data_area_s, fdpt[1]));
+}
+
+static void
+ram_probe(void)
+{
+    dprintf(3, "Find memory size\n");
+    if (CONFIG_COREBOOT) {
+        coreboot_fill_map();
+    } else {
+        // On emulators, get memory size from nvram.
+        u32 rs = ((inb_cmos(CMOS_MEM_EXTMEM2_LOW) << 16)
+                  | (inb_cmos(CMOS_MEM_EXTMEM2_HIGH) << 24));
+        if (rs)
+            rs += 16 * 1024 * 1024;
+        else
+            rs = (((inb_cmos(CMOS_MEM_EXTMEM_LOW) << 10)
+                   | (inb_cmos(CMOS_MEM_EXTMEM_HIGH) << 18))
+                  + 1 * 1024 * 1024);
+        RamSize = rs;
+        add_e820(0, rs, E820_RAM);
+
+        // Check for memory over 4Gig
+        u64 high = ((inb_cmos(CMOS_MEM_HIGHMEM_LOW) << 16)
+                    | (inb_cmos(CMOS_MEM_HIGHMEM_MID) << 24)
+                    | ((u64)inb_cmos(CMOS_MEM_HIGHMEM_HIGH) << 32));
+        RamSizeOver4G = high;
+        add_e820(0x100000000ull, high, E820_RAM);
+
+        /* reserve 256KB BIOS area at the end of 4 GB */
+        add_e820(0xfffc0000, 256*1024, E820_RESERVED);
+    }
 
-static void
-timer_setup()
-{
-    u32 seconds = bcd2bin(inb_cmos(CMOS_RTC_SECONDS));
-    u32 ticks = (seconds * 18206507) / 1000000;
-    u32 minutes = bcd2bin(inb_cmos(CMOS_RTC_MINUTES));
-    ticks += (minutes * 10923904) / 10000;
-    u32 hours = bcd2bin(inb_cmos(CMOS_RTC_HOURS));
-    ticks += (hours * 65543427) / 1000;
-    bda->timer_counter = ticks;
-    bda->timer_rollover = 0;
-}
+    // Don't declare any memory between 0xa0000 and 0x100000
+    add_e820(0xa0000, 0x50000, E820_HOLE);
 
-static void
-pic_setup()
-{
-    outb(0x11, PORT_PIC1);
-    outb(0x11, PORT_PIC2_DATA);
-    outb(0x08, PORT_PIC1_DATA);
-    outb(0x70, PORT_PIC2_DATA);
-    outb(0x04, PORT_PIC1_DATA);
-    outb(0x02, PORT_PIC2_DATA);
-    outb(0x01, PORT_PIC1_DATA);
-    outb(0x01, PORT_PIC2_DATA);
-    outb(0xb8, PORT_PIC1_DATA);
-    if (CONFIG_PS2_MOUSE)
-        outb(0x8f, PORT_PIC2_DATA);
-    else
-        outb(0x9f, PORT_PIC2_DATA);
-}
+    // Mark known areas as reserved.
+    u16 ebda_seg = get_ebda_seg();
+    add_e820((u32)MAKE_FLATPTR(ebda_seg, 0), GET_EBDA2(ebda_seg, size) * 1024
+             , E820_RESERVED);
+    add_e820(BUILD_BIOS_ADDR, BUILD_BIOS_SIZE, E820_RESERVED);
 
-static void
-floppy_drive_post()
-{
-    u8 type = inb_cmos(CMOS_FLOPPY_DRIVE_TYPE);
-    u8 out = 0;
-    if (type & 0xf0)
-        out |= 0x07;
-    if (type & 0x0f)
-        out |= 0x70;
-    bda->floppy_harddisk_info = out;
-    outb(0x02, PORT_DMA1_MASK_REG);
-
-    bda->ivecs[0x1E].offset = OFFSET_diskette_param_table2;
-}
+    if (CONFIG_KVM)
+        // 4 pages before the bios, 3 pages for vmx tss pages, the
+        // other page for EPT real mode pagetable
+        add_e820(0xfffbc000, 4*4096, E820_RESERVED);
 
-static void
-ata_init()
-{
-    // hdidmap  and cdidmap init.
-    u8 device;
-    for (device=0; device < CONFIG_MAX_ATA_DEVICES; device++) {
-        ebda->ata.hdidmap[device] = CONFIG_MAX_ATA_DEVICES;
-        ebda->ata.cdidmap[device] = CONFIG_MAX_ATA_DEVICES;
-    }
+    dprintf(1, "Ram Size=0x%08x\n", RamSize);
 }
 
 static void
-fill_hdinfo(struct fdpt_s *info, u8 typecmos, u8 basecmos)
+init_bios_tables(void)
 {
-    u8 type = inb_cmos(typecmos);
-    if (type != 47)
-        // XXX - halt
+    if (CONFIG_COREBOOT)
+        // XXX - not supported on coreboot yet.
         return;
 
-    info->precompensation = (inb_cmos(basecmos+4) << 8) | inb_cmos(basecmos+3);
-    info->drive_control_byte = inb_cmos(basecmos+5);
-    info->landing_zone = (inb_cmos(basecmos+7) << 8) | inb_cmos(basecmos+6);
-    u16 cyl = (inb_cmos(basecmos+1) << 8) | inb_cmos(basecmos+0);
-    u8 heads = inb_cmos(basecmos+2);
-    u8 sectors = inb_cmos(basecmos+8);
-    if (cyl < 1024) {
-        // no logical CHS mapping used, just physical CHS
-        // use Standard Fixed Disk Parameter Table (FDPT)
-        info->cylinders = cyl;
-        info->heads = heads;
-        info->sectors = sectors;
-        return;
-    }
-
-    // complies with Phoenix style Translated Fixed Disk Parameter
-    // Table (FDPT)
-    info->phys_cylinders = cyl;
-    info->phys_heads = heads;
-    info->phys_sectors = sectors;
-    info->sectors = sectors;
-    info->a0h_signature = 0xa0;
-    if (cyl > 8192) {
-        cyl >>= 4;
-        heads <<= 4;
-    } else if (cyl > 4096) {
-        cyl >>= 3;
-        heads <<= 3;
-    } else if (cyl > 2048) {
-        cyl >>= 2;
-        heads <<= 2;
-    }
-    info->cylinders = cyl;
-    info->heads = heads;
-    info->checksum = ~checksum((u8*)info, sizeof(*info)-1) + 1;
-}
-
-static void
-hard_drive_post()
-{
-    outb(0x0a, 0x03f6); // 0000 1010 = reserved, disable IRQ 14
-    bda->disk_count = 1;
-    bda->disk_control_byte = 0xc0;
-
-    // move disk geometry data from CMOS to EBDA disk parameter table(s)
-    u8 diskinfo = inb_cmos(CMOS_DISK_DATA);
-    if ((diskinfo & 0xf0) == 0xf0)
-        // Fill EBDA table for hard disk 0.
-        fill_hdinfo(&ebda->fdpt0, CMOS_DISK_DRIVE1_TYPE, CMOS_DISK_DRIVE1_CYL);
-    if ((diskinfo & 0x0f) == 0x0f)
-        // XXX - bochs halts on any other type
-        // Fill EBDA table for hard disk 1.
-        fill_hdinfo(&ebda->fdpt0, CMOS_DISK_DRIVE2_TYPE, CMOS_DISK_DRIVE2_CYL);
-}
+    create_pirtable();
 
+    mptable_init();
 
-static void
-init_boot_vectors()
-{
-    // Clear out the IPL table.
-    memset(ipl, 0, sizeof(*ipl));
-
-    // Floppy drive
-    struct ipl_entry_s *ip = &ipl->table[0];
-    ip->type = IPL_TYPE_FLOPPY;
-    ip++;
-
-    // First HDD
-    ip->type = IPL_TYPE_HARDDISK;
-    ip++;
-
-    // CDROM
-    if (CONFIG_ELTORITO_BOOT) {
-        ip->type = IPL_TYPE_CDROM;
-        ip++;
-    }
+    smbios_init();
 
-    ipl->count = ip - ipl->table;
-    ipl->sequence = 0xffff;
+    acpi_bios_init();
 }
 
+// Main setup code.
 static void
-callrom(u16 seg, u16 offset)
+post()
 {
-    struct bregs br;
-    memset(&br, 0, sizeof(br));
-    br.es = 0xf000;
-    br.di = OFFSET_pnp_string;
-    br.cs = seg;
-    br.ip = offset;
-    call16(&br);
-}
+    init_ivt();
+    init_bda();
 
-static void
-rom_scan(u32 start, u32 end)
-{
-    u8 *p = (u8*)start;
-    for (; p <= (u8*)end; p += 2048) {
-        u8 *rom = p;
-        if (*(u16*)rom != 0xaa55)
-            continue;
-        u32 len = rom[2] * 512;
-        if (checksum(rom, len) != 0)
-            continue;
-        p = (u8*)(((u32)p + len) / 2048 * 2048);
-        callrom(PTR_TO_SEG(rom), PTR_TO_OFFSET(rom + 3));
-
-        // Look at the ROM's PnP Expansion header.  Properly, we're supposed
-        // to init all the ROMs and then go back and build an IPL table of
-        // all the bootable devices, but we can get away with one pass.
-        if (rom[0x1a] != '$' || rom[0x1b] != 'P'
-            || rom[0x1c] != 'n' || rom[0x1d] != 'P')
-            continue;
-        // 0x1A is also the offset into the expansion header of...
-        // the Bootstrap Entry Vector, or zero if there is none.
-        u16 entry = *(u16*)&rom[0x1a+0x1a];
-        if (!entry)
-            continue;
-        // Found a device that thinks it can boot the system.  Record
-        // its BEV and product name string.
-
-        if (ipl->count >= ARRAY_SIZE(ipl->table))
-            continue;
-
-        struct ipl_entry_s *ip = &ipl->table[ipl->count];
-        ip->type = IPL_TYPE_BEV;
-        ip->vector = (PTR_TO_SEG(rom) << 16) | entry;
-
-        u16 desc = *(u16*)&rom[0x1a+0x10];
-        if (desc)
-            ip->description = (PTR_TO_SEG(rom) << 16) | desc;
-
-        ipl->count++;
-    }
-}
+    pic_setup();
+    timer_setup();
+    mathcp_setup();
 
-static void
-post()
-{
-    BX_INFO("Start bios\n");
+    smp_probe_setup();
 
-    init_bda();
-    init_handlers();
-    init_ebda();
+    memmap_setup();
+    ram_probe();
+    mtrr_setup();
+
+    pnp_setup();
+    vga_setup();
 
-    pit_setup();
     kbd_setup();
     lpt_setup();
     serial_setup();
-    timer_setup();
-    pic_setup();
+    mouse_setup();
 
-    rom_scan(0xc0000, 0xc7800);
+    pci_bios_setup();
+    smm_init();
 
-    printf("BIOS - begin\n\n");
+    init_bios_tables();
+    memmap_finalize();
 
-    // XXX - need to do pci stuff
-    //pci_setup();
-    init_boot_vectors();
+    boot_setup();
 
-    floppy_drive_post();
-    hard_drive_post();
-    if (CONFIG_ATA)
-        ata_init();
+    floppy_drive_setup();
+    hard_drive_setup();
 
-    init_boot_vectors();
-    rom_scan(0xc8000, 0xe0000);
-
-    callrom(0xf000, OFFSET_begin_boot);
+    optionrom_setup();
 }
 
-static void
-init_dma()
+// 32-bit entry point.
+void VISIBLE32
+_start()
 {
-    // first reset the DMA controllers
-    outb(0, PORT_DMA1_MASTER_CLEAR);
-    outb(0, PORT_DMA2_MASTER_CLEAR);
+    init_dma();
 
-    // then initialize the DMA controllers
-    outb(0xc0, PORT_DMA2_MODE_REG);
-    outb(0x00, PORT_DMA2_MASK_REG);
-}
+    debug_serial_setup();
+    dprintf(1, "Start bios\n");
 
-static void
-eoi_jmp_post()
-{
-    // XXX - this is supposed to jump without changing any memory -
-    // but the stack has been altered by the time the code gets here.
-    eoi_both_pics();
-    struct bregs br;
-    memset(&br, 0, sizeof(br));
-    br.cs = bda->jump_cs_ip >> 16;
-    br.ip = bda->jump_cs_ip;
-    call16(&br);
-}
+    // Allow writes to modify bios area (0xf0000)
+    make_bios_writable();
 
-static void
-check_restart_status()
-{
-    // Get and then clear CMOS shutdown status.
-    u8 status = inb_cmos(CMOS_RESET_CODE);
-    outb_cmos(0, CMOS_RESET_CODE);
+    // Perform main setup code.
+    post();
 
-    if (status == 0x00 || status == 0x09 || status >= 0x0d)
-        // Normal post
-        return;
+    // Present the user with a bootup menu.
+    interactive_bootmenu();
 
-    if (status == 0x05)
-        eoi_jmp_post();
+    // Setup bios checksum.
+    BiosChecksum = -checksum((u8*)BUILD_BIOS_ADDR, BUILD_BIOS_SIZE - 1);
 
-    BX_PANIC("Unimplemented shutdown status: %02x\n", status);
-}
+    // Prep for boot process.
+    make_bios_readonly();
 
-void VISIBLE
-_start()
-{
-    init_dma();
-    check_restart_status();
-
-    post();
+    // Invoke int 19 to start boot process.
+    dprintf(3, "Jump to int19\n");
+    struct bregs br;
+    memset(&br, 0, sizeof(br));
+    call16_int(0x19, &br);
 }
+
+// Ughh - some older gcc compilers have a bug which causes VISIBLE32
+// functions to not be exported as a global variable - force _start
+// to be global here.
+asm(".global _start");