1 // 32bit code to Power On Self Test (POST) a machine.
3 // Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net>
4 // Copyright (C) 2002 MandrakeSoft S.A.
6 // This file may be distributed under the terms of the GNU GPLv3 license.
8 #include "ioport.h" // PORT_*
9 #include "config.h" // CONFIG_*
10 #include "cmos.h" // CMOS_*
11 #include "util.h" // memset
12 #include "biosvar.h" // struct bios_data_area_s
13 #include "ata.h" // hard_drive_setup
14 #include "disk.h" // floppy_drive_setup
15 #include "memmap.h" // add_e820
16 #include "pic.h" // pic_setup
17 #include "pci.h" // create_pirtable
18 #include "acpi.h" // acpi_bios_init
19 #include "bregs.h" // struct bregs
21 #define bda ((struct bios_data_area_s *)MAKE_FARPTR(SEG_BDA, 0))
22 #define ebda ((struct extended_bios_data_area_s *)MAKE_FARPTR(SEG_EBDA, 0))
25 set_irq(int vector, void *loc)
27 SET_BDA(ivecs[vector].seg, SEG_BIOS);
28 SET_BDA(ivecs[vector].offset, (u32)loc - BUILD_BIOS_ADDR);
31 // Symbols defined in romlayout.S
32 extern void dummy_iret_handler();
33 extern void entry_08();
34 extern void entry_09();
35 extern void entry_hwirq();
36 extern void entry_0e();
37 extern void entry_10();
38 extern void entry_11();
39 extern void entry_12();
40 extern void entry_13();
41 extern void entry_14();
42 extern void entry_15();
43 extern void entry_16();
44 extern void entry_17();
45 extern void entry_18();
46 extern void entry_19();
47 extern void entry_1a();
48 extern void entry_1c();
49 extern void entry_40();
50 extern void entry_70();
51 extern void entry_74();
52 extern void entry_75();
53 extern void entry_76();
58 dprintf(3, "init bda\n");
59 memset(bda, 0, sizeof(*bda));
61 SET_BDA(mem_size_kb, BASE_MEM_IN_K);
65 set_irq(i, &dummy_iret_handler);
67 set_irq(0x08, &entry_08);
68 set_irq(0x09, &entry_09);
69 //set_irq(0x0a, &entry_hwirq);
70 //set_irq(0x0b, &entry_hwirq);
71 //set_irq(0x0c, &entry_hwirq);
72 //set_irq(0x0d, &entry_hwirq);
73 set_irq(0x0e, &entry_0e);
74 //set_irq(0x0f, &entry_hwirq);
75 set_irq(0x10, &entry_10);
76 set_irq(0x11, &entry_11);
77 set_irq(0x12, &entry_12);
78 set_irq(0x13, &entry_13);
79 set_irq(0x14, &entry_14);
80 set_irq(0x15, &entry_15);
81 set_irq(0x16, &entry_16);
82 set_irq(0x17, &entry_17);
83 set_irq(0x18, &entry_18);
84 set_irq(0x19, &entry_19);
85 set_irq(0x1a, &entry_1a);
86 set_irq(0x1c, &entry_1c);
87 set_irq(0x40, &entry_40);
88 set_irq(0x70, &entry_70);
89 //set_irq(0x71, &entry_hwirq);
90 //set_irq(0x72, &entry_hwirq);
91 //set_irq(0x73, &entry_hwirq);
92 set_irq(0x74, &entry_74);
93 set_irq(0x75, &entry_75);
94 set_irq(0x76, &entry_76);
95 //set_irq(0x77, &entry_hwirq);
97 // set vector 0x79 to zero
98 // this is used by 'gardian angel' protection system
99 SET_BDA(ivecs[0x79].seg, 0);
100 SET_BDA(ivecs[0x79].offset, 0);
102 set_irq(0x1E, &diskette_param_table2);
108 memset(ebda, 0, sizeof(*ebda));
109 ebda->size = EBDA_SIZE;
110 SET_BDA(ebda_seg, SEG_EBDA);
111 SET_BDA(ivecs[0x41].seg, SEG_EBDA);
112 SET_BDA(ivecs[0x41].offset
113 , offsetof(struct extended_bios_data_area_s, fdpt[0]));
114 SET_BDA(ivecs[0x46].seg, SEG_EBDA);
115 SET_BDA(ivecs[0x41].offset
116 , offsetof(struct extended_bios_data_area_s, fdpt[1]));
122 dprintf(3, "Find memory size\n");
123 if (CONFIG_COREBOOT) {
126 // On emulators, get memory size from nvram.
127 u32 rs = (inb_cmos(CMOS_MEM_EXTMEM2_LOW)
128 | (inb_cmos(CMOS_MEM_EXTMEM2_HIGH) << 8)) * 65536;
130 rs += 16 * 1024 * 1024;
132 rs = ((inb_cmos(CMOS_MEM_EXTMEM_LOW)
133 | (inb_cmos(CMOS_MEM_EXTMEM_HIGH) << 8)) * 1024
135 SET_EBDA(ram_size, rs);
136 add_e820(0, rs, E820_RAM);
138 /* reserve 256KB BIOS area at the end of 4 GB */
139 add_e820(0xfffc0000, 256*1024, E820_RESERVED);
142 // Don't declare any memory between 0xa0000 and 0x100000
143 add_e820(0xa0000, 0x50000, E820_HOLE);
145 // Mark known areas as reserved.
146 add_e820((u32)MAKE_FARPTR(SEG_EBDA, 0), EBDA_SIZE * 1024, E820_RESERVED);
147 add_e820(BUILD_BIOS_ADDR, BUILD_BIOS_SIZE, E820_RESERVED);
149 dprintf(1, "ram_size=0x%08x\n", GET_EBDA(ram_size));
153 init_bios_tables(void)
156 // XXX - not supported on coreboot yet.
173 dprintf(3, "init boot device ordering\n");
176 struct ipl_entry_s *ip = &ebda->ipl.table[0];
177 ip->type = IPL_TYPE_FLOPPY;
181 ip->type = IPL_TYPE_HARDDISK;
185 if (CONFIG_CDROM_BOOT) {
186 ip->type = IPL_TYPE_CDROM;
190 ebda->ipl.count = ip - ebda->ipl.table;
191 ebda->ipl.sequence = 0xffff;
192 if (CONFIG_COREBOOT) {
193 // XXX - hardcode defaults for coreboot.
194 ebda->ipl.bootorder = 0x00000231;
195 ebda->ipl.checkfloppysig = 1;
197 // On emulators, get boot order from nvram.
198 ebda->ipl.bootorder = (inb_cmos(CMOS_BIOS_BOOTFLAG2)
199 | ((inb_cmos(CMOS_BIOS_BOOTFLAG1) & 0xf0) << 4));
200 if (!(inb_cmos(CMOS_BIOS_BOOTFLAG1) & 1))
201 ebda->ipl.checkfloppysig = 1;
205 // Execute a given option rom.
207 callrom(u16 seg, u16 offset)
210 memset(&br, 0, sizeof(br));
212 // starts 1 past for alignment
213 extern char pnp_string[];
214 br.di = (u32)pnp_string - BUILD_BIOS_ADDR + 1;
219 debug_serial_setup();
222 // Find and run any "option roms" found in the given address range.
224 rom_scan(u32 start, u32 end)
227 for (; p <= (u8*)end; p += 2048) {
229 if (*(u16*)rom != 0xaa55)
231 u32 len = rom[2] * 512;
232 u8 sum = checksum(rom, len);
234 dprintf(1, "Found option rom with bad checksum:"
235 " loc=%p len=%d sum=%x\n"
239 p = (u8*)(((u32)p + len) / 2048 * 2048);
240 dprintf(1, "Running option rom at %p\n", rom+3);
241 callrom(FARPTR_TO_SEG(rom), FARPTR_TO_OFFSET(rom + 3));
243 if (GET_BDA(ebda_seg) != SEG_EBDA)
244 BX_PANIC("Option rom at %p attempted to move ebda from %x to %x\n"
245 , rom, SEG_EBDA, GET_BDA(ebda_seg));
247 // Look at the ROM's PnP Expansion header. Properly, we're supposed
248 // to init all the ROMs and then go back and build an IPL table of
249 // all the bootable devices, but we can get away with one pass.
250 if (rom[0x1a] != '$' || rom[0x1b] != 'P'
251 || rom[0x1c] != 'n' || rom[0x1d] != 'P')
253 // 0x1A is also the offset into the expansion header of...
254 // the Bootstrap Entry Vector, or zero if there is none.
255 u16 entry = *(u16*)&rom[0x1a+0x1a];
258 // Found a device that thinks it can boot the system. Record
259 // its BEV and product name string.
261 if (ebda->ipl.count >= ARRAY_SIZE(ebda->ipl.table))
264 struct ipl_entry_s *ip = &ebda->ipl.table[ebda->ipl.count];
265 ip->type = IPL_TYPE_BEV;
266 ip->vector = (FARPTR_TO_SEG(rom) << 16) | entry;
268 u16 desc = *(u16*)&rom[0x1a+0x10];
270 ip->description = (u32)MAKE_FARPTR(FARPTR_TO_SEG(rom), desc);
295 dprintf(1, "Scan for VGA option rom\n");
296 rom_scan(0xc0000, 0xc7800);
298 printf("BIOS - begin\n\n");
306 floppy_drive_setup();
311 dprintf(1, "Scan for option roms\n");
312 rom_scan(0xc8000, 0xe0000);
315 // Clear .bss section for C code.
319 dprintf(3, "clearing .bss section\n");
320 extern char __bss_start[], __bss_end[];
321 memset(__bss_start, 0, __bss_end - __bss_start);
324 // Reset DMA controller
328 // first reset the DMA controllers
329 outb(0, PORT_DMA1_MASTER_CLEAR);
330 outb(0, PORT_DMA2_MASTER_CLEAR);
332 // then initialize the DMA controllers
333 outb(0xc0, PORT_DMA2_MODE_REG);
334 outb(0x00, PORT_DMA2_MASK_REG);
337 // Check if the machine was setup with a special restart vector.
339 check_restart_status()
341 // Get and then clear CMOS shutdown status.
342 u8 status = inb_cmos(CMOS_RESET_CODE);
343 outb_cmos(0, CMOS_RESET_CODE);
345 if (status == 0x00 || status == 0x09 || status >= 0x0d)
349 if (status != 0x05) {
350 BX_PANIC("Unimplemented shutdown status: %02x\n", status);
354 // XXX - this is supposed to jump without changing any memory -
355 // but the stack has been altered by the time the code gets here.
358 memset(&br, 0, sizeof(br));
359 br.cs = GET_BDA(jump_cs_ip) >> 16;
360 br.ip = GET_BDA(jump_cs_ip);
364 // 32-bit entry point.
369 check_restart_status();
371 debug_serial_setup();
372 dprintf(1, "Start bios\n");
374 // Setup for .bss and .data sections
376 make_bios_writable();
378 // Perform main setup code.
381 // Present the user with a bootup menu.
382 interactive_bootmenu();
384 // Setup bios checksum.
385 extern char bios_checksum;
386 bios_checksum = -checksum((u8*)BUILD_BIOS_ADDR, BUILD_BIOS_SIZE - 1);
388 // Prep for boot process.
389 make_bios_readonly();
392 // Invoke int 19 to start boot process.
393 dprintf(3, "Jump to int19\n");
395 memset(&br, 0, sizeof(br));
396 call16_int(0x19, &br);
399 // Ughh - some older gcc compilers have a bug which causes VISIBLE32
400 // functions to not be exported as a global variable - force _start
401 // to be global here.
402 asm(".global _start");