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" // BIOS_CONFIG_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)
38 set_code_success(regs);
42 handle_152401(struct bregs *regs)
45 set_code_success(regs);
49 handle_152402(struct bregs *regs)
51 regs->al = !!(inb(PORT_A20) & 0x20);
52 set_code_success(regs);
56 handle_152403(struct bregs *regs)
59 set_code_success(regs);
63 handle_1524XX(struct bregs *regs)
65 set_code_fail(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)
84 set_code_success(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
126 SET_SEG(ES, regs->es);
128 u16 base15_00 = (regs->es << 4) + si;
129 u16 base23_16 = regs->es >> 12;
130 if (base15_00 < (u16)(regs->es<<4))
132 SET_VAR(ES, *(u16*)(si+0x08+0), 47); // limit 15:00 = 6 * 8bytes/descriptor
133 SET_VAR(ES, *(u16*)(si+0x08+2), base15_00);// base 15:00
134 SET_VAR(ES, *(u8 *)(si+0x08+4), base23_16);// base 23:16
135 SET_VAR(ES, *(u8 *)(si+0x08+5), 0x93); // access
136 SET_VAR(ES, *(u16*)(si+0x08+6), 0x0000); // base 31:24/reserved/limit 19:16
138 // Initialize CS descriptor
139 SET_VAR(ES, *(u16*)(si+0x20+0), 0xffff);// limit 15:00 = normal 64K limit
140 SET_VAR(ES, *(u16*)(si+0x20+2), 0x0000);// base 15:00
141 SET_VAR(ES, *(u8 *)(si+0x20+4), 0x000f);// base 23:16
142 SET_VAR(ES, *(u8 *)(si+0x20+5), 0x9b); // access
143 SET_VAR(ES, *(u16*)(si+0x20+6), 0x0000);// base 31:24/reserved/limit 19:16
145 // Initialize SS descriptor
146 u16 ss = GET_SEG(SS);
148 base23_16 = ss >> 12;
149 SET_VAR(ES, *(u16*)(si+0x28+0), 0xffff); // limit 15:00 = normal 64K limit
150 SET_VAR(ES, *(u16*)(si+0x28+2), base15_00);// base 15:00
151 SET_VAR(ES, *(u8 *)(si+0x28+4), base23_16);// base 23:16
152 SET_VAR(ES, *(u8 *)(si+0x28+5), 0x93); // access
153 SET_VAR(ES, *(u16*)(si+0x28+6), 0x0000); // base 31:24/reserved/limit 19:16
155 u16 count = regs->cx;
157 // Load new descriptor tables
158 "lgdtw %%es:0x8(%%si)\n"
159 "lidtw %%cs:pmode_IDT_info\n"
162 "movl %%cr0, %%eax\n"
164 "movl %%eax, %%cr0\n"
166 // far jump to flush CPU queue after transition to protected mode
167 "ljmpw $0x0020, $1f\n"
170 // GDT points to valid descriptor table, now load DS, ES
171 "movw $0x10, %%ax\n" // 010 000 = 2nd descriptor in table, TI=GDT, RPL=00
173 "movw $0x18, %%ax\n" // 011 000 = 3rd descriptor in table, TI=GDT, RPL=00
176 // move CX words from DS:SI to ES:DI
181 // reset PG bit in CR0 ???
182 "movl %%cr0, %%eax\n"
184 "movl %%eax, %%cr0\n"
186 // far jump to flush CPU queue after transition to real mode
187 "ljmpw $0xf000, $2f\n"
190 // restore IDT to normal real-mode defaults
191 "lidt %%cs:rmode_IDT_info\n"
193 // Restore %ds (from %ss)
196 : "+c"(count), "+S"(si)
197 : : "eax", "di", "cc"); // XXX - also clobbers %es
199 set_a20(prev_a20_enable);
201 set_code_success(regs);
204 // Get the amount of extended memory (above 1M)
206 handle_1588(struct bregs *regs)
208 u32 rs = GET_EBDA(ram_size);
210 // According to Ralf Brown's interrupt the limit should be 15M,
211 // but real machines mostly return max. 63M.
212 if (rs > 64*1024*1024)
213 regs->ax = 63 * 1024;
215 regs->ax = (rs - 1*1024*1024) / 1024;
219 // Device busy interrupt. Called by Int 16h when no key available
221 handle_1590(struct bregs *regs)
225 // Interrupt complete. Called by Int 16h when key becomes available
227 handle_1591(struct bregs *regs)
231 // keyboard intercept
233 handle_154f(struct bregs *regs)
235 // set_fail(regs); -- don't report this failure.
240 handle_15c0(struct bregs *regs)
243 regs->bx = (u32)&BIOS_CONFIG_TABLE;
244 set_code_success(regs);
248 handle_15c1(struct bregs *regs)
250 regs->es = GET_BDA(ebda_seg);
255 handle_15e801(struct bregs *regs)
257 // my real system sets ax and bx to 0
258 // this is confirmed by Ralph Brown list
259 // but syslinux v1.48 is known to behave
260 // strangely if ax is set to 0
261 // regs.u.r16.ax = 0;
262 // regs.u.r16.bx = 0;
264 u32 rs = GET_EBDA(ram_size);
266 // Get the amount of extended memory (above 1M)
267 if (rs > 16*1024*1024) {
270 // Get the amount of extended memory above 16M in 64k blocks
271 regs->dx = (rs - 16*1024*1024) / (64*1024);
273 regs->cx = (rs - 1*1024*1024) / 1024;
277 // Set configured memory equal to extended memory
285 set_e820_range(struct bregs *regs, u32 start, u32 end, u16 type, int last)
287 u32 size = end - start;
288 SET_FARVAR(regs->es, *(u64*)(regs->di+0), start);
289 SET_FARVAR(regs->es, *(u64*)(regs->di+8), size);
290 SET_FARVAR(regs->es, *(u16*)(regs->di+16), type);
291 SET_FARVAR(regs->es, *(u16*)(regs->di+18), 0x0);
297 regs->eax = 0x534D4150;
302 // XXX - should create e820 memory map in post and just copy it here.
304 handle_15e820(struct bregs *regs)
306 if (regs->edx != 0x534D4150) {
307 set_code_fail(regs, RET_EUNSUPPORTED);
311 u32 extended_memory_size = GET_EBDA(ram_size);
312 // greater than EFF00000???
313 if (extended_memory_size > 0xf0000000)
314 // everything after this is reserved memory until we get to 0x100000000
315 extended_memory_size = 0xf0000000;
319 set_e820_range(regs, 0x0000000L, 0x0009fc00L, E820_RAM, 0);
322 set_e820_range(regs, 0x0009fc00L, 0x000a0000L, E820_RESERVED, 0);
325 set_e820_range(regs, 0x000e8000L, 0x00100000L, E820_RESERVED, 0);
328 set_e820_range(regs, 0x00100000L
329 , extended_memory_size - CONFIG_ACPI_DATA_SIZE
334 extended_memory_size - CONFIG_ACPI_DATA_SIZE,
335 extended_memory_size, E820_ACPI, 0);
338 /* 256KB BIOS area at the end of 4 GB */
339 set_e820_range(regs, 0xfffc0000L, 0x00000000L, E820_RESERVED, 1);
341 default: /* AX=E820, DX=534D4150, BX unrecognized */
342 set_code_fail(regs, RET_EUNSUPPORTED);
347 handle_15e8XX(struct bregs *regs)
349 set_code_fail(regs, RET_EUNSUPPORTED);
353 handle_15e8(struct bregs *regs)
356 case 0x01: handle_15e801(regs); break;
357 case 0x20: handle_15e820(regs); break;
358 default: handle_15e8XX(regs); break;
363 handle_15XX(struct bregs *regs)
365 set_code_fail(regs, RET_EUNSUPPORTED);
368 // INT 15h System Services Entry Point
370 handle_15(struct bregs *regs)
374 case 0x24: handle_1524(regs); break;
375 case 0x4f: handle_154f(regs); break;
376 case 0x52: handle_1552(regs); break;
377 case 0x53: handle_1553(regs); break;
378 case 0x83: handle_1583(regs); break;
379 case 0x86: handle_1586(regs); break;
380 case 0x87: handle_1587(regs); break;
381 case 0x88: handle_1588(regs); break;
382 case 0x90: handle_1590(regs); break;
383 case 0x91: handle_1591(regs); break;
384 case 0xc0: handle_15c0(regs); break;
385 case 0xc1: handle_15c1(regs); break;
386 case 0xc2: handle_15c2(regs); break;
387 case 0xe8: handle_15e8(regs); break;
388 default: handle_15XX(regs); break;
392 // INT 12h Memory Size Service Entry Point
394 handle_12(struct bregs *regs)
397 regs->ax = GET_BDA(mem_size_kb);
400 // INT 11h Equipment List Service Entry Point
402 handle_11(struct bregs *regs)
405 regs->ax = GET_BDA(equipment_list_flags);
408 // INT 05h Print Screen Service Entry Point
410 handle_05(struct bregs *regs)
415 // INT 10h Video Support Service Entry Point
417 handle_10(struct bregs *regs)
420 // dont do anything, since the VGA BIOS handles int10h requests
427 BX_PANIC("NMI Handler called\n");
430 // INT 75 - IRQ13 - MATH COPROCESSOR EXCEPTION
437 outb(0, PORT_MATH_CLEAR);
442 memset(&br, 0, sizeof(br));
443 call16_int(0x02, &br);