system.c@ 82176

Last change on this file since 82176 was 81941, checked in by vboxsync, 5 years ago
BIOS: Removed obsolete code, moved a break statement to match comment (should not really matter).
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 30.3 KB

Line
1	/* $Id: system.c 81941 2019-11-18 13:37:44Z vboxsync $ */
2	/** @file
3	* PC BIOS - ???
4	*/
5
6	/*
7	* Copyright (C) 2006-2019 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	* --------------------------------------------------------------------
17	*
18	* This code is based on:
19	*
20	* ROM BIOS for use with Bochs/Plex86/QEMU emulation environment
21	*
22	* Copyright (C) 2002 MandrakeSoft S.A.
23	*
24	* MandrakeSoft S.A.
25	* 43, rue d'Aboukir
26	* 75002 Paris - France
27	* http://www.linux-mandrake.com/
28	* http://www.mandrakesoft.com/
29	*
30	* This library is free software; you can redistribute it and/or
31	* modify it under the terms of the GNU Lesser General Public
32	* License as published by the Free Software Foundation; either
33	* version 2 of the License, or (at your option) any later version.
34	*
35	* This library is distributed in the hope that it will be useful,
36	* but WITHOUT ANY WARRANTY; without even the implied warranty of
37	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
38	* Lesser General Public License for more details.
39	*
40	* You should have received a copy of the GNU Lesser General Public
41	* License along with this library; if not, write to the Free Software
42	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
43	*
44	*/
45
46	/*
47	* Oracle LGPL Disclaimer: For the avoidance of doubt, except that if any license choice
48	* other than GPL or LGPL is available it will apply instead, Oracle elects to use only
49	* the Lesser General Public License version 2.1 (LGPLv2) at this time for any software where
50	* a choice of LGPL license versions is made available with the language indicating
51	* that LGPLv2 or any later version may be used, or where a choice of which version
52	* of the LGPL is applied is otherwise unspecified.
53	*/
54
55
56	#include <stdint.h>
57	#include "biosint.h"
58	#include "inlines.h"
59
60	#if DEBUG_INT15
61	# define BX_DEBUG_INT15(...) BX_DEBUG(__VA_ARGS__)
62	#else
63	# define BX_DEBUG_INT15(...)
64	#endif
65
66
67	#define UNSUPPORTED_FUNCTION 0x86 /* Specific to INT 15h. */
68
69	#define BIOS_CONFIG_TABLE 0xe6f5 /** @todo configurable? put elsewhere? */
70
71	#define ACPI_DATA_SIZE 0x00010000L /** @todo configurable? put elsewhere? */
72
73	extern int pmode_IDT;
74	extern int rmode_IDT;
75
76	uint16_t read_ss(void);
77	#pragma aux read_ss = "mov ax, ss" modify exact [ax] nomemory;
78
79	#if VBOX_BIOS_CPU >= 80386
80
81	/* The 386+ code uses CR0 to switch to/from protected mode.
82	* Quite straightforward.
83	*/
84
85	void pm_stack_save(uint16_t cx, uint16_t es, uint16_t si);
86	#pragma aux pm_stack_save = \
87	".386" \
88	"push ds" \
89	"push eax" \
90	"xor ax, ax" \
91	"mov ds, ax" \
92	"mov ds:[467h], sp" \
93	"mov ds:[469h], ss" \
94	parm [cx] [es] [si] modify nomemory;
95
96	/* Uses position independent code to build a far return... because it was
97	* too hard to figure out how to code the far call in inline assembler.
98	*
99	* NB: It would be lovely to do 'add [sp],N' instead of 'pop ax; add ax,M;
100	* push ax'. Unfortunately the former cannot be encoded, though 'add [esp],N'
101	* can be on 386 and later -- but it may be unwise to assume that the high
102	* bits of ESP are all zero.
103	*/
104	void pm_enter(void);
105	#pragma aux pm_enter = \
106	".386p" \
107	"lgdt fword ptr es:[si+8]" \
108	"lidt fword ptr cs:pmode_IDT" \
109	"push 20h" \
110	"call pentry" \
111	"pentry:" \
112	"pop ax" \
113	"add ax, 0Eh" \
114	"push ax" \
115	"mov eax, cr0" \
116	"or al, 1" \
117	"mov cr0, eax" \
118	"retf" \
119	"pm_pm:" \
120	"mov ax, 10h" \
121	"mov ds, ax" \
122	"add al, 08h" \
123	"mov es, ax" \
124	"add al, 10h" \
125	"mov ss, ax" \
126	modify nomemory;
127
128	/* Restore segment limits to real mode compatible values and
129	* return to real mode.
130	*/
131	void pm_exit(void);
132	#pragma aux pm_exit = \
133	".386p" \
134	"mov ax, 28h" \
135	"mov ds, ax" \
136	"mov es, ax" \
137	"push 0F000h" \
138	"call pexit" \
139	"pexit:" \
140	"pop ax" \
141	"add ax, 0Eh" \
142	"push ax" \
143	"mov eax, cr0" \
144	"and al, 0FEh" \
145	"mov cr0, eax" \
146	"retf" \
147	"real_mode:" \
148	"lidt fword ptr cs:rmode_IDT" \
149	modify nomemory;
150
151	/* Restore stack and reload segment registers in real mode to ensure
152	* real mode compatible selector+base.
153	*/
154	void pm_stack_restore(void);
155	#pragma aux pm_stack_restore = \
156	".386" \
157	"xor ax, ax" \
158	"mov ds, ax" \
159	"mov es, ax" \
160	"lss sp, ds:[467h]" \
161	"pop eax" \
162	"pop ds" \
163	modify nomemory;
164
165	#elif VBOX_BIOS_CPU >= 80286
166
167	/* The 286 code uses LMSW to switch to protected mode but it has to reset
168	* the CPU to get back to real mode. Ugly! See return_blkmove in orgs.asm
169	* for the other matching half.
170	*/
171	void pm_stack_save(uint16_t cx, uint16_t es, uint16_t si, uint16_t frame);
172	#pragma aux pm_stack_save = \
173	"xor ax, ax" \
174	"mov ds, ax" \
175	"mov ds:[467h], bx" \
176	"mov ds:[469h], ss" \
177	parm [cx] [es] [si] [bx] modify nomemory;
178
179	/* Uses position independent code... because it was too hard to figure
180	* out how to code the far call in inline assembler.
181	*/
182	void pm_enter(void);
183	#pragma aux pm_enter = \
184	".286p" \
185	"lgdt fword ptr es:[si+8]" \
186	"lidt fword ptr cs:pmode_IDT" \
187	"push 20h" \
188	"call pentry" \
189	"pentry:" \
190	"pop ax" \
191	"add ax, 0Eh" \
192	"push ax" \
193	"smsw ax" \
194	"or al, 1" \
195	"lmsw ax" \
196	"retf" \
197	"pm_pm:" \
198	"mov ax, 10h" \
199	"mov ds, ax" \
200	"add al, 08h" \
201	"mov es, ax" \
202	"add al, 10h" \
203	"mov ss, ax" \
204	modify nomemory;
205
206	/* Set up shutdown status and reset the CPU. The POST code
207	* will regain control. Port 80h is written with status.
208	* Code 9 is written to CMOS shutdown status byte (0Fh).
209	* CPU is triple faulted. .
210	*/
211	void pm_exit(void);
212	#pragma aux pm_exit = \
213	"xor ax, ax" \
214	"out 80h, al" \
215	"mov al, 0Fh" \
216	"out 70h, al" \
217	"mov al, 09h" \
218	"out 71h, al" \
219	".286p" \
220	"lidt fword ptr cs:pmode_IDT" \
221	"int 3" \
222	modify nomemory;
223
224	/* Dummy. Actually done in return_blkmove. */
225	void pm_stack_restore(void);
226	#pragma aux pm_stack_restore = \
227	"rm_return:" \
228	modify nomemory;
229
230	#endif
231
232	/* NB: CX is set earlier in pm_stack_save */
233	void pm_copy(void);
234	#pragma aux pm_copy = \
235	"xor si, si" \
236	"xor di, di" \
237	"cld" \
238	"rep movsw" \
239	modify [si di cx] nomemory;
240
241	/* The pm_switch has a few crucial differences from pm_enter, hence
242	* it is replicated here. Uses LMSW to avoid trashing high word of eax.
243	*/
244	void pm_switch(uint16_t reg_si);
245	#pragma aux pm_switch = \
246	".286p" \
247	"lgdt fword ptr es:[si+08h]" \
248	"lidt fword ptr es:[si+10h]" \
249	"push 38h" \
250	"call pentry" \
251	"pentry:" \
252	"pop ax" \
253	"add ax, 0Eh" \
254	"push ax" \
255	"smsw ax" \
256	"or al, 1" \
257	"lmsw ax" \
258	"retf" \
259	"pm_pm:" \
260	"mov ax, 18h" \
261	"mov ds, ax" \
262	"add al, 08h" \
263	"mov es, ax" \
264	"add al, 08h" \
265	"mov ss, ax" \
266	parm [si] modify nomemory;
267
268	/* Return to caller - we do not use IRET because we should not enable
269	* interrupts. Note that AH must be zero on exit.
270	* WARNING: Needs to be adapted if calling sequence is modified!
271	*/
272	void pm_unwind(uint16_t args);
273	#pragma aux pm_unwind = \
274	".286" \
275	"mov sp, ax" \
276	"popa" \
277	"add sp, 6" \
278	"pop cx" \
279	"pop ax" \
280	"pop ax" \
281	"mov ax, 30h" \
282	"push ax" \
283	"push cx" \
284	"retf" \
285	parm [ax] modify nomemory aborts;
286
287	/// @todo This method is silly. The RTC should be programmed to fire an interrupt
288	// instead of hogging the CPU with inaccurate code.
289	void timer_wait(uint32_t usec_wait)
290	{
291	uint32_t cycles;
292	uint8_t old_val;
293	uint8_t cur_val;
294
295	/* We wait in 15 usec increments. */
296	cycles = usec_wait / 15;
297
298	old_val = inp(0x61) & 0x10;
299	while (cycles--) {
300	/* Wait 15us. */
301	do {
302	cur_val = inp(0x61) & 0x10;
303	} while (cur_val != old_val);
304	old_val = cur_val;
305	}
306	}
307
308	bx_bool set_enable_a20(bx_bool val)
309	{
310	uint8_t oldval;
311
312	// Use PS/2 System Control port A to set A20 enable
313
314	// get current setting first
315	oldval = inb(0x92);
316
317	// change A20 status
318	if (val)
319	outb(0x92, oldval \| 0x02);
320	else
321	outb(0x92, oldval & 0xfd);
322
323	return((oldval & 0x02) != 0);
324	}
325
326	/// @todo move elsewhere?
327	#define AX r.gr.u.r16.ax
328	#define BX r.gr.u.r16.bx
329	#define CX r.gr.u.r16.cx
330	#define DX r.gr.u.r16.dx
331	#define SI r.gr.u.r16.si
332	#define DI r.gr.u.r16.di
333	#define BP r.gr.u.r16.bp
334	#define SP r.gr.u.r16.sp
335	#define FLAGS r.fl.u.r16.flags
336	#define EAX r.gr.u.r32.eax
337	#define EBX r.gr.u.r32.ebx
338	#define ECX r.gr.u.r32.ecx
339	#define EDX r.gr.u.r32.edx
340	#define ESI r.gr.u.r32.esi
341	#define EDI r.gr.u.r32.edi
342	#define ES r.es
343
344
345	void BIOSCALL int15_function(sys_regs_t r)
346	{
347	uint16_t bRegister;
348	uint8_t irqDisable;
349
350	BX_DEBUG_INT15("int15 AX=%04x\n",AX);
351
352	switch (GET_AH()) {
353	case 0x00: /* assorted functions */
354	if (GET_AL() != 0xc0)
355	goto undecoded;
356	/* GRUB calls int15 with ax=0x00c0 to get the ROM configuration table,
357	* which we don't support, but logging that event is annoying. In fact
358	* it is likely that they just misread some specs, because there is a
359	* int15 BIOS function AH=0xc0 which sounds quite similar to what GRUB
360	* wants to achieve. */
361	SET_CF();
362	SET_AH(UNSUPPORTED_FUNCTION);
363	break;
364	case 0x24: /* A20 Control */
365	switch (GET_AL()) {
366	case 0x00:
367	set_enable_a20(0);
368	CLEAR_CF();
369	SET_AH(0);
370	break;
371	case 0x01:
372	set_enable_a20(1);
373	CLEAR_CF();
374	SET_AH(0);
375	break;
376	case 0x02:
377	SET_AL( (inb(0x92) >> 1) & 0x01 );
378	CLEAR_CF();
379	SET_AH(0);
380	break;
381	case 0x03:
382	CLEAR_CF();
383	SET_AH(0);
384	BX = 3;
385	break;
386	default:
387	BX_INFO("int15: Func 24h, subfunc %02xh, A20 gate control not supported\n", (unsigned) GET_AL());
388	SET_CF();
389	SET_AH(UNSUPPORTED_FUNCTION);
390	}
391	break;
392
393	/* These are here just to avoid warnings being logged. */
394	case 0x22: /* Locate ROM BASIC (tough when we don't have any.) */
395	case 0x41: /* PC Convertible, wait for external events. */
396	case 0xC7: /* PS/2, get memory map. */
397	SET_CF();
398	SET_AH(UNSUPPORTED_FUNCTION);
399	break;
400
401	/// @todo Why does this need special handling? All we need is to set CF
402	// but not handle this as an unknown function (regardless of CPU type).
403	case 0x4f:
404	/* keyboard intercept */
405	#if VBOX_BIOS_CPU >= 80286
406	// nop
407	#else
408	SET_AH(UNSUPPORTED_FUNCTION);
409	#endif
410	SET_CF();
411	break;
412
413	case 0x52: // removable media eject
414	CLEAR_CF();
415	SET_AH(0); // "ok ejection may proceed"
416	break;
417
418	case 0x83: {
419	if( GET_AL() == 0 ) {
420	// Set Interval requested.
421	if( ( read_byte( 0x40, 0xA0 ) & 1 ) == 0 ) {
422	// Interval not already set.
423	write_byte( 0x40, 0xA0, 1 ); // Set status byte.
424	write_word( 0x40, 0x98, ES ); // Byte location, segment
425	write_word( 0x40, 0x9A, BX ); // Byte location, offset
426	write_word( 0x40, 0x9C, DX ); // Low word, delay
427	write_word( 0x40, 0x9E, CX ); // High word, delay.
428	CLEAR_CF( );
429	irqDisable = inb( 0xA1 );
430	outb( 0xA1, irqDisable & 0xFE );
431	bRegister = inb_cmos( 0xB ); // Unmask IRQ8 so INT70 will get through.
432	outb_cmos( 0xB, bRegister \| 0x40 ); // Turn on the Periodic Interrupt timer
433	} else {
434	// Interval already set.
435	BX_DEBUG_INT15("int15: Func 83h, failed, already waiting.\n" );
436	SET_CF();
437	SET_AH(UNSUPPORTED_FUNCTION);
438	}
439	} else if( GET_AL() == 1 ) {
440	// Clear Interval requested
441	write_byte( 0x40, 0xA0, 0 ); // Clear status byte
442	CLEAR_CF( );
443	bRegister = inb_cmos( 0xB );
444	outb_cmos( 0xB, bRegister & ~0x40 ); // Turn off the Periodic Interrupt timer
445	} else {
446	BX_DEBUG_INT15("int15: Func 83h, failed.\n" );
447	SET_CF();
448	SET_AH(UNSUPPORTED_FUNCTION);
449	SET_AL(GET_AL() - 1);
450	}
451
452	break;
453	}
454
455	case 0x86:
456	// Wait for CX:DX microseconds. currently using the
457	// refresh request port 0x61 bit4, toggling every 15usec
458	int_enable();
459	timer_wait(((uint32_t)CX << 16) \| DX);
460	break;
461
462	case 0x88:
463	// Get the amount of extended memory (above 1M)
464	#if VBOX_BIOS_CPU >= 80286
465	AX = (inb_cmos(0x31) << 8) \| inb_cmos(0x30);
466
467	#if VBOX_BIOS_CPU >= 80386
468	// According to Ralf Brown's interrupt the limit should be 15M,
469	// but real machines mostly return max. 63M.
470	if(AX > 0xffc0)
471	AX = 0xffc0;
472	#else
473	// An AT compatible cannot have more than 15M extended memory.
474	// If more is reported, some software (e.g. Windows 3.1) gets
475	// quite upset.
476	if(AX > 0x3c00)
477	AX = 0x3c00;
478	#endif
479
480	CLEAR_CF();
481	#else
482	SET_AH(UNSUPPORTED_FUNCTION);
483	SET_CF();
484	#endif
485	break;
486
487	case 0x89:
488	// Switch to Protected Mode.
489	// ES:DI points to user-supplied GDT
490	// BH/BL contains starting interrupt numbers for PIC0/PIC1
491	// This subfunction does not return!
492
493	// turn off interrupts
494	int_disable(); /// @todo aren't they off already?
495
496	set_enable_a20(1); // enable A20 line; we're supposed to fail if that fails
497
498	// Initialize CS descriptor for BIOS
499	write_word(ES, SI+0x38+0, 0xffff);// limit 15:00 = normal 64K limit
500	write_word(ES, SI+0x38+2, 0x0000);// base 15:00
501	write_byte(ES, SI+0x38+4, 0x000f);// base 23:16 (hardcoded to f000:0000)
502	write_byte(ES, SI+0x38+5, 0x9b); // access
503	write_word(ES, SI+0x38+6, 0x0000);// base 31:24/reserved/limit 19:16
504
505	/* Reprogram the PICs. */
506	outb(PIC_MASTER, PIC_CMD_INIT);
507	outb(PIC_SLAVE, PIC_CMD_INIT);
508	outb(PIC_MASTER + 1, GET_BH());
509	outb(PIC_SLAVE + 1, GET_BL());
510	outb(PIC_MASTER + 1, 4);
511	outb(PIC_SLAVE + 1, 2);
512	outb(PIC_MASTER + 1, 1);
513	outb(PIC_SLAVE + 1, 1);
514	/* Mask all IRQs, user must re-enable. */
515	outb(PIC_MASTER_MASK, 0xff);
516	outb(PIC_SLAVE_MASK, 0xff);
517
518	pm_switch(SI);
519	pm_unwind((uint16_t)&r);
520
521	break;
522
523	case 0x90:
524	/* Device busy interrupt. Called by Int 16h when no key available */
525	break;
526
527	case 0x91:
528	/* Interrupt complete. Called by Int 16h when key becomes available */
529	break;
530
531	case 0xbf:
532	BX_INFO("*** int 15h function AH=bf not yet supported!\n");
533	SET_CF();
534	SET_AH(UNSUPPORTED_FUNCTION);
535	break;
536
537	case 0xC0:
538	CLEAR_CF();
539	SET_AH(0);
540	BX = BIOS_CONFIG_TABLE;
541	ES = 0xF000;
542	break;
543
544	case 0xc1:
545	ES = read_word(0x0040, 0x000E);
546	CLEAR_CF();
547	break;
548
549	case 0xd8:
550	bios_printf(BIOS_PRINTF_DEBUG, "EISA BIOS not present\n");
551	SET_CF();
552	SET_AH(UNSUPPORTED_FUNCTION);
553	break;
554
555	/* Make the BIOS warning for pretty much every Linux kernel start
556	* disappear - it calls with ax=0xe980 to figure out SMI info. */
557	case 0xe9: /* SMI functions (SpeedStep and similar things) */
558	SET_CF();
559	SET_AH(UNSUPPORTED_FUNCTION);
560	break;
561	case 0xec: /* AMD64 target operating mode callback */
562	if (GET_AL() != 0)
563	goto undecoded;
564	SET_AH(0);
565	if (GET_BL() >= 1 && GET_BL() <= 3)
566	CLEAR_CF(); /* Accepted value. */
567	else
568	SET_CF(); /* Reserved, error. */
569	break;
570	undecoded:
571	default:
572	BX_INFO("*** int 15h function AX=%04x, BX=%04x not yet supported!\n",
573	(unsigned) AX, (unsigned) BX);
574	SET_CF();
575	SET_AH(UNSUPPORTED_FUNCTION);
576	break;
577	}
578	}
579
580	#if VBOX_BIOS_CPU >= 80386
581
582	typedef struct {
583	uint32_t start;
584	uint32_t xstart;
585	uint32_t len;
586	uint32_t xlen;
587	uint32_t type;
588	} mem_range_t;
589
590	void set_e820_range(uint16_t reg_ES, uint16_t reg_DI, uint32_t start, uint32_t end,
591	uint8_t extra_start, uint8_t extra_end, uint16_t type)
592	{
593	mem_range_t __far *range;
594
595	range = reg_ES :> (mem_range_t *)reg_DI;
596	range->start = start;
597	range->xstart = extra_start;
598	end -= start;
599	extra_end -= extra_start;
600	range->len = end;
601	range->xlen = extra_end;
602	range->type = type;
603	}
604
605	void BIOSCALL int15_function32(sys32_regs_t r)
606	{
607	uint32_t extended_memory_size=0; // 64bits long
608	uint32_t extra_lowbits_memory_size=0;
609	uint8_t extra_highbits_memory_size=0;
610	uint32_t mcfgStart, mcfgSize;
611
612	BX_DEBUG_INT15("int15 AX=%04x\n",AX);
613
614	switch (GET_AH()) {
615	case 0xd0:
616	if (GET_AL() != 0x4f)
617	goto int15_unimplemented;
618	if (EBX == 0x50524f43 && ECX == 0x4d4f4445 && ESI == 0 && EDI == 0)
619	{
620	CLEAR_CF();
621	ESI = EBX;
622	EDI = ECX;
623	EAX = 0x49413332;
624	}
625	else
626	goto int15_unimplemented;
627	break;
628
629	case 0xe8:
630	switch(GET_AL()) {
631	case 0x20: // coded by osmaker aka K.J.
632	if(EDX == 0x534D4150) {
633	extended_memory_size = inb_cmos(0x35);
634	extended_memory_size <<= 8;
635	extended_memory_size \|= inb_cmos(0x34);
636	extended_memory_size *= 64;
637	#ifndef VBOX /* The following excludes 0xf0000000 thru 0xffffffff. Trust DevPcBios.cpp to get this right. */
638	// greater than EFF00000???
639	if(extended_memory_size > 0x3bc000) {
640	extended_memory_size = 0x3bc000; // everything after this is reserved memory until we get to 0x100000000
641	}
642	#endif /* !VBOX */
643	extended_memory_size *= 1024;
644	extended_memory_size += (16L * 1024 * 1024);
645
646	if(extended_memory_size <= (16L * 1024 * 1024)) {
647	extended_memory_size = inb_cmos(0x31);
648	extended_memory_size <<= 8;
649	extended_memory_size \|= inb_cmos(0x30);
650	extended_memory_size *= 1024;
651	extended_memory_size += (1L * 1024 * 1024);
652	}
653
654	/* This is the amount of memory above 4GB measured in 64KB units. */
655	extra_lowbits_memory_size = inb_cmos(0x62);
656	extra_lowbits_memory_size <<= 8;
657	extra_lowbits_memory_size \|= inb_cmos(0x61);
658	extra_lowbits_memory_size <<= 16;
659	extra_highbits_memory_size = inb_cmos(0x63);
660	/* 0x64 and 0x65 can be used if we need to dig 1 TB or more at a later point. */
661
662	mcfgStart = 0;
663	mcfgSize = 0;
664
665	switch(BX)
666	{
667	case 0:
668	set_e820_range(ES, DI,
669	0x0000000L, 0x0009fc00L, 0, 0, 1);
670	EBX = 1;
671	break;
672	case 1:
673	set_e820_range(ES, DI,
674	0x0009fc00L, 0x000a0000L, 0, 0, 2);
675	EBX = 2;
676	break;
677	case 2:
678	/* Mark the BIOS as reserved. VBox doesn't currently
679	* use the 0xe0000-0xeffff area. It does use the
680	* 0xd0000-0xdffff area for the BIOS logo, but it's
681	* not worth marking it as reserved. (this is not
682	* true anymore because the VGA adapter handles the logo stuff)
683	* The whole 0xe0000-0xfffff can be used for the BIOS.
684	* Note that various
685	* Windows versions don't accept (read: in debug builds
686	* they trigger the "Too many similar traps" assertion)
687	* a single reserved range from 0xd0000 to 0xffffff.
688	* A 128K area starting from 0xd0000 works. */
689	set_e820_range(ES, DI,
690	0x000f0000L, 0x00100000L, 0, 0, 2);
691	EBX = 3;
692	break;
693	case 3:
694	set_e820_range(ES, DI,
695	0x00100000L,
696	extended_memory_size - ACPI_DATA_SIZE, 0, 0, 1);
697	EBX = 4;
698	break;
699	case 4:
700	set_e820_range(ES, DI,
701	extended_memory_size - ACPI_DATA_SIZE,
702	extended_memory_size, 0, 0, 3); // ACPI RAM
703	EBX = 5;
704	break;
705	case 5:
706	set_e820_range(ES, DI,
707	0xfec00000,
708	0xfec00000 + 0x1000, 0, 0, 2); // I/O APIC
709	EBX = 6;
710	break;
711	case 6:
712	set_e820_range(ES, DI,
713	0xfee00000,
714	0xfee00000 + 0x1000, 0, 0, 2); // Local APIC
715	EBX = 7;
716	break;
717	case 7:
718	/* 256KB BIOS area at the end of 4 GB */
719	/* We don't set the end to 1GB here and rely on the 32-bit
720	unsigned wrap around effect (0-0xfffc0000L). */
721	set_e820_range(ES, DI,
722	0xfffc0000L, 0x00000000L, 0, 0, 2);
723	if (mcfgStart != 0)
724	EBX = 8;
725	else
726	{
727	if (extra_highbits_memory_size \|\| extra_lowbits_memory_size)
728	EBX = 9;
729	else
730	EBX = 0;
731	}
732	break;
733	case 8:
734	/* PCI MMIO config space (MCFG) */
735	set_e820_range(ES, DI,
736	mcfgStart, mcfgStart + mcfgSize, 0, 0, 2);
737
738	if (extra_highbits_memory_size \|\| extra_lowbits_memory_size)
739	EBX = 9;
740	else
741	EBX = 0;
742	break;
743	case 9:
744	/* Mapping of memory above 4 GB if present.
745	Note1: set_e820_range needs do no borrowing in the
746	subtraction because of the nice numbers.
747	Note2* works only up to 1TB because of uint8_t for
748	the upper bits!*/
749	if (extra_highbits_memory_size \|\| extra_lowbits_memory_size)
750	{
751	set_e820_range(ES, DI,
752	0x00000000L, extra_lowbits_memory_size,
753	1 /x4GB/, extra_highbits_memory_size + 1 /x4GB/, 1);
754	EBX = 0;
755	break;
756	}
757	/* fall thru */
758	default: /* AX=E820, DX=534D4150, BX unrecognized */
759	goto int15_unimplemented;
760	break;
761	}
762	EAX = 0x534D4150;
763	ECX = 0x14;
764	CLEAR_CF();
765	} else {
766	// if DX != 0x534D4150)
767	goto int15_unimplemented;
768	}
769	break;
770
771	case 0x01:
772	// do we have any reason to fail here ?
773	CLEAR_CF();
774
775	// my real system sets ax and bx to 0
776	// this is confirmed by Ralph Brown list
777	// but syslinux v1.48 is known to behave
778	// strangely if ax is set to 0
779	// regs.u.r16.ax = 0;
780	// regs.u.r16.bx = 0;
781
782	// Get the amount of extended memory (above 1M)
783	CX = (inb_cmos(0x31) << 8) \| inb_cmos(0x30);
784
785	// limit to 15M
786	if(CX > 0x3c00)
787	CX = 0x3c00;
788
789	// Get the amount of extended memory above 16M in 64k blocks
790	DX = (inb_cmos(0x35) << 8) \| inb_cmos(0x34);
791
792	// Set configured memory equal to extended memory
793	AX = CX;
794	BX = DX;
795	break;
796	default: /* AH=0xE8?? but not implemented */
797	goto int15_unimplemented;
798	}
799	break;
800	int15_unimplemented:
801	// fall into the default case
802	default:
803	BX_INFO("*** int 15h function AX=%04x, BX=%04x not yet supported!\n",
804	(unsigned) AX, (unsigned) BX);
805	SET_CF();
806	SET_AL(UNSUPPORTED_FUNCTION);
807	break;
808	}
809	}
810	#endif /* VBOX_BIOS_CPU >= 80386 */
811
812	#if VBOX_BIOS_CPU >= 80286
813
814	#undef FLAGS
815	#define FLAGS r.ra.flags.u.r16.flags
816
817	/* Function 0x87 handled separately due to specific stack layout requirements. */
818	void BIOSCALL int15_blkmove(disk_regs_t r)
819	{
820	uint16_t base15_00;
821	uint8_t base23_16;
822	uint16_t ss;
823
824	// +++ should probably have descriptor checks
825	// +++ should have exception handlers
826
827	// turn off interrupts
828	int_disable(); /// @todo aren't they disabled already?
829
830	set_enable_a20(1); // enable A20 line
831
832	// 128K max of transfer on 386+ ???
833	// source == destination ???
834
835	// ES:SI points to descriptor table
836	// offset use initially comments
837	// ==============================================
838	// 00..07 Unused zeros Null descriptor
839	// 08..0f scratch zeros work area used by BIOS
840	// 10..17 source ssssssss source of data
841	// 18..1f dest dddddddd destination of data
842	// 20..27 CS zeros filled in by BIOS
843	// 28..2f SS zeros filled in by BIOS
844
845	//es:si
846	//eeee0
847	//0ssss
848	//-----
849
850	// check for access rights of source & dest here
851
852	// Initialize GDT descriptor
853	base15_00 = (ES << 4) + SI;
854	base23_16 = ES >> 12;
855	if (base15_00 < (ES<<4))
856	base23_16++;
857	write_word(ES, SI+0x08+0, 47); // limit 15:00 = 6 * 8bytes/descriptor
858	write_word(ES, SI+0x08+2, base15_00);// base 15:00
859	write_byte(ES, SI+0x08+4, base23_16);// base 23:16
860	write_byte(ES, SI+0x08+5, 0x93); // access
861	write_word(ES, SI+0x08+6, 0x0000); // base 31:24/reserved/limit 19:16
862
863	// Initialize CS descriptor
864	write_word(ES, SI+0x20+0, 0xffff);// limit 15:00 = normal 64K limit
865	write_word(ES, SI+0x20+2, 0x0000);// base 15:00
866	write_byte(ES, SI+0x20+4, 0x000f);// base 23:16
867	write_byte(ES, SI+0x20+5, 0x9b); // access
868	write_word(ES, SI+0x20+6, 0x0000);// base 31:24/reserved/limit 19:16
869
870	// Initialize SS descriptor
871	ss = read_ss();
872	base15_00 = ss << 4;
873	base23_16 = ss >> 12;
874	write_word(ES, SI+0x28+0, 0xffff); // limit 15:00 = normal 64K limit
875	write_word(ES, SI+0x28+2, base15_00);// base 15:00
876	write_byte(ES, SI+0x28+4, base23_16);// base 23:16
877	write_byte(ES, SI+0x28+5, 0x93); // access
878	write_word(ES, SI+0x28+6, 0x0000); // base 31:24/reserved/limit 19:16
879
880	#if VBOX_BIOS_CPU >= 80386
881	/* Not taking the address of the parameter allows the code generator
882	* produce slightly better code for some unknown reason.
883	*/
884	pm_stack_save(CX, ES, SI);
885	#else
886	pm_stack_save(CX, ES, SI, FP_OFF(&r));
887	#endif
888	pm_enter();
889	pm_copy();
890	pm_exit();
891	pm_stack_restore();
892
893	set_enable_a20(0); // unconditionally disable A20 line
894
895	// turn interrupts back on
896	int_enable();
897
898	SET_AH(0);
899	CLEAR_CF();
900	}
901	#endif /* VBOX_BIOS_CPU >= 80286 */

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source: vbox/trunk/src/VBox/Devices/PC/BIOS/system.c@ 82176

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