1 // 16bit system callbacks
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 "util.h" // irq_restore
9 #include "biosvar.h" // CONFIG_BIOS_TABLE
10 #include "ioport.h" // inb
11 #include "cmos.h" // inb_cmos
14 #define E820_RESERVED 2
17 #define E820_UNUSABLE 5
19 // Use PS2 System Control port A to set A20 enable
23 // get current setting first
24 u8 newval, oldval = inb(PORT_A20);
26 newval = oldval | 0x02;
28 newval = oldval & ~0x02;
29 outb(newval, PORT_A20);
31 return (newval & 0x02) != 0;
35 handle_152400(struct bregs *regs)
42 handle_152401(struct bregs *regs)
49 handle_152402(struct bregs *regs)
51 regs->al = !!(inb(PORT_A20) & 0x20);
56 handle_152403(struct bregs *regs)
63 handle_1524XX(struct bregs *regs)
65 handle_ret(regs, RET_EUNSUPPORTED);
69 handle_1524(struct bregs *regs)
72 case 0x00: handle_152400(regs); break;
73 case 0x01: handle_152401(regs); break;
74 case 0x02: handle_152402(regs); break;
75 case 0x03: handle_152403(regs); break;
76 default: handle_1524XX(regs); break;
80 // removable media eject
82 handle_1552(struct bregs *regs)
87 // Wait for CX:DX microseconds. currently using the
88 // refresh request port 0x61 bit4, toggling every 15usec
90 handle_1586(struct bregs *regs)
93 usleep((regs->cx << 16) | regs->dx);
98 handle_1587(struct bregs *regs)
100 // +++ should probably have descriptor checks
101 // +++ should have exception handlers
103 u8 prev_a20_enable = set_a20(1); // enable A20 line
105 // 128K max of transfer on 386+ ???
106 // source == destination ???
108 // ES:SI points to descriptor table
109 // offset use initially comments
110 // ==============================================
111 // 00..07 Unused zeros Null descriptor
112 // 08..0f GDT zeros filled in by BIOS
113 // 10..17 source ssssssss source of data
114 // 18..1f dest dddddddd destination of data
115 // 20..27 CS zeros filled in by BIOS
116 // 28..2f SS zeros filled in by BIOS
123 // check for access rights of source & dest here
125 // Initialize GDT descriptor
127 u16 base15_00 = (regs->es << 4) + si;
128 u16 base23_16 = regs->es >> 12;
129 if (base15_00 < (regs->es<<4))
131 SET_VAR(ES, *(u16*)(si+0x08+0), 47); // limit 15:00 = 6 * 8bytes/descriptor
132 SET_VAR(ES, *(u16*)(si+0x08+2), base15_00);// base 15:00
133 SET_VAR(ES, *(u8 *)(si+0x08+4), base23_16);// base 23:16
134 SET_VAR(ES, *(u8 *)(si+0x08+5), 0x93); // access
135 SET_VAR(ES, *(u16*)(si+0x08+6), 0x0000); // base 31:24/reserved/limit 19:16
137 // Initialize CS descriptor
138 SET_VAR(ES, *(u16*)(si+0x20+0), 0xffff);// limit 15:00 = normal 64K limit
139 SET_VAR(ES, *(u16*)(si+0x20+2), 0x0000);// base 15:00
140 SET_VAR(ES, *(u8 *)(si+0x20+4), 0x000f);// base 23:16
141 SET_VAR(ES, *(u8 *)(si+0x20+5), 0x9b); // access
142 SET_VAR(ES, *(u16*)(si+0x20+6), 0x0000);// base 31:24/reserved/limit 19:16
144 // Initialize SS descriptor
145 u16 ss = GET_SEG(SS);
147 base23_16 = ss >> 12;
148 SET_VAR(ES, *(u16*)(si+0x28+0), 0xffff); // limit 15:00 = normal 64K limit
149 SET_VAR(ES, *(u16*)(si+0x28+2), base15_00);// base 15:00
150 SET_VAR(ES, *(u8 *)(si+0x28+4), base23_16);// base 23:16
151 SET_VAR(ES, *(u8 *)(si+0x28+5), 0x93); // access
152 SET_VAR(ES, *(u16*)(si+0x28+6), 0x0000); // base 31:24/reserved/limit 19:16
155 // Load new descriptor tables
157 "lidt %%cs:pmode_IDT_info\n"
160 "movl %%cr0, %%eax\n"
162 "movl %%eax, %%cr0\n"
164 // far jump to flush CPU queue after transition to protected mode
165 "ljmpw $0x0020, $1f\n"
168 // GDT points to valid descriptor table, now load DS, ES
169 "movw $0x10, %%ax\n" // 010 000 = 2nd descriptor in table, TI=GDT, RPL=00
171 "movw $0x18, %%ax\n" // 011 000 = 3rd descriptor in table, TI=GDT, RPL=00
174 // move CX words from DS:SI to ES:DI
180 // reset PG bit in CR0 ???
181 "movl %%cr0, %%eax\n"
183 "movl %%eax, %%cr0\n"
185 // far jump to flush CPU queue after transition to real mode
186 "ljmpw $0xf000, $2f\n"
189 // restore IDT to normal real-mode defaults
190 "lidt %%cs:rmode_IDT_info\n"
192 // Restore %ds (from %ss)
195 : : "c" (regs->cx), "r" (si + 8)
196 : "eax", "di", "si"); // XXX - also clobbers %es
198 set_a20(prev_a20_enable);
203 // Get the amount of extended memory (above 1M)
205 handle_1588(struct bregs *regs)
207 regs->al = inb_cmos(CMOS_MEM_EXTMEM_LOW);
208 regs->ah = inb_cmos(CMOS_MEM_EXTMEM_HIGH);
209 // According to Ralf Brown's interrupt the limit should be 15M,
210 // but real machines mostly return max. 63M.
211 if (regs->ax > 0xffc0)
216 // Device busy interrupt. Called by Int 16h when no key available
218 handle_1590(struct bregs *regs)
222 // Interrupt complete. Called by Int 16h when key becomes available
224 handle_1591(struct bregs *regs)
228 // keyboard intercept
230 handle_154f(struct bregs *regs)
236 handle_15c0(struct bregs *regs)
239 regs->bx = (u16)&BIOS_CONFIG_TABLE;
244 handle_15c1(struct bregs *regs)
246 regs->es = GET_BDA(ebda_seg);
251 handle_15e801(struct bregs *regs)
253 // my real system sets ax and bx to 0
254 // this is confirmed by Ralph Brown list
255 // but syslinux v1.48 is known to behave
256 // strangely if ax is set to 0
257 // regs.u.r16.ax = 0;
258 // regs.u.r16.bx = 0;
260 // Get the amount of extended memory (above 1M)
261 regs->cl = inb_cmos(CMOS_MEM_EXTMEM_LOW);
262 regs->ch = inb_cmos(CMOS_MEM_EXTMEM_HIGH);
265 if (regs->cx > 0x3c00)
268 // Get the amount of extended memory above 16M in 64k blocs
269 regs->dl = inb_cmos(CMOS_MEM_EXTMEM2_LOW);
270 regs->dh = inb_cmos(CMOS_MEM_EXTMEM2_HIGH);
272 // Set configured memory equal to extended memory
279 #define ACPI_DATA_SIZE 0x00010000L
282 set_e820_range(u16 DI, u32 start, u32 end, u16 type)
284 SET_VAR(ES, *(u16*)(DI+0), start);
285 SET_VAR(ES, *(u16*)(DI+2), start >> 16);
286 SET_VAR(ES, *(u16*)(DI+4), 0x00);
287 SET_VAR(ES, *(u16*)(DI+6), 0x00);
290 SET_VAR(ES, *(u16*)(DI+8), end);
291 SET_VAR(ES, *(u16*)(DI+10), end >> 16);
292 SET_VAR(ES, *(u16*)(DI+12), 0x0000);
293 SET_VAR(ES, *(u16*)(DI+14), 0x0000);
295 SET_VAR(ES, *(u16*)(DI+16), type);
296 SET_VAR(ES, *(u16*)(DI+18), 0x0);
299 // XXX - should create e820 memory map in post and just copy it here.
301 handle_15e820(struct bregs *regs)
303 if (regs->edx != 0x534D4150) {
304 handle_ret(regs, RET_EUNSUPPORTED);
308 u32 extended_memory_size = inb_cmos(CMOS_MEM_EXTMEM2_HIGH);
309 extended_memory_size <<= 8;
310 extended_memory_size |= inb_cmos(CMOS_MEM_EXTMEM2_LOW);
311 extended_memory_size *= 64;
312 // greater than EFF00000???
313 if (extended_memory_size > 0x3bc000)
314 // everything after this is reserved memory until we get to 0x100000000
315 extended_memory_size = 0x3bc000;
316 extended_memory_size *= 1024;
317 extended_memory_size += (16L * 1024 * 1024);
319 if (extended_memory_size <= (16L * 1024 * 1024)) {
320 extended_memory_size = inb_cmos(CMOS_MEM_EXTMEM_HIGH);
321 extended_memory_size <<= 8;
322 extended_memory_size |= inb_cmos(CMOS_MEM_EXTMEM_LOW);
323 extended_memory_size *= 1024;
328 set_e820_range(regs->di, 0x0000000L, 0x0009fc00L, E820_RAM);
330 regs->eax = 0x534D4150;
335 set_e820_range(regs->di, 0x0009fc00L, 0x000a0000L, E820_RESERVED);
337 regs->eax = 0x534D4150;
342 set_e820_range(regs->di, 0x000e8000L, 0x00100000L, E820_RESERVED);
344 regs->eax = 0x534D4150;
349 set_e820_range(regs->di, 0x00100000L,
350 extended_memory_size - ACPI_DATA_SIZE, E820_RAM);
352 regs->eax = 0x534D4150;
357 set_e820_range(regs->di,
358 extended_memory_size - ACPI_DATA_SIZE,
359 extended_memory_size, E820_ACPI); // ACPI RAM
361 regs->eax = 0x534D4150;
366 /* 256KB BIOS area at the end of 4 GB */
367 set_e820_range(regs->di, 0xfffc0000L, 0x00000000L, E820_RESERVED);
369 regs->eax = 0x534D4150;
373 default: /* AX=E820, DX=534D4150, BX unrecognized */
374 handle_ret(regs, RET_EUNSUPPORTED);
379 handle_15e8XX(struct bregs *regs)
381 handle_ret(regs, RET_EUNSUPPORTED);
385 handle_15e8(struct bregs *regs)
388 case 0x01: handle_15e801(regs); break;
389 case 0x20: handle_15e820(regs); break;
390 default: handle_15e8XX(regs); break;
395 handle_15XX(struct bregs *regs)
397 handle_ret(regs, RET_EUNSUPPORTED);
400 // INT 15h System Services Entry Point
402 handle_15(struct bregs *regs)
406 case 0x24: handle_1524(regs); break;
407 case 0x4f: handle_154f(regs); break;
408 case 0x52: handle_1552(regs); break;
409 case 0x53: handle_1553(regs); break;
410 case 0x83: handle_1583(regs); break;
411 case 0x86: handle_1586(regs); break;
412 case 0x87: handle_1587(regs); break;
413 case 0x88: handle_1588(regs); break;
414 case 0x90: handle_1590(regs); break;
415 case 0x91: handle_1591(regs); break;
416 case 0xc0: handle_15c0(regs); break;
417 case 0xc1: handle_15c1(regs); break;
418 case 0xc2: handle_15c2(regs); break;
419 case 0xe8: handle_15e8(regs); break;
420 default: handle_15XX(regs); break;
425 // INT 12h Memory Size Service Entry Point
427 handle_12(struct bregs *regs)
430 regs->ax = GET_BDA(mem_size_kb);
434 // INT 11h Equipment List Service Entry Point
436 handle_11(struct bregs *regs)
439 regs->ax = GET_BDA(equipment_list_flags);
443 // INT 05h Print Screen Service Entry Point
445 handle_05(struct bregs *regs)
450 // INT 10h Video Support Service Entry Point
452 handle_10(struct bregs *regs)
455 // dont do anything, since the VGA BIOS handles int10h requests
459 handle_nmi(struct bregs *regs)
465 // INT 75 - IRQ13 - MATH COPROCESSOR EXCEPTION
467 handle_75(struct bregs *regs)
472 outb(0, PORT_MATH_CLEAR);
477 memset(&br, 0, sizeof(br));
478 call16_int(0x02, &br);