--- /dev/null
+// Handler for int 0x15 "system" calls
+//
+// 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 LGPLv3 license.
+
+#include "biosvar.h" // GET_GLOBAL
+#include "bregs.h" // struct bregs
+#include "hw/pic.h" // pic_reset
+#include "malloc.h" // LegacyRamSize
+#include "memmap.h" // E820_RAM
+#include "output.h" // debug_enter
+#include "string.h" // memcpy_far
+#include "util.h" // handle_1553
+#include "x86.h" // set_a20
+
+static void
+handle_152400(struct bregs *regs)
+{
+ set_a20(0);
+ set_code_success(regs);
+}
+
+static void
+handle_152401(struct bregs *regs)
+{
+ set_a20(1);
+ set_code_success(regs);
+}
+
+static void
+handle_152402(struct bregs *regs)
+{
+ regs->al = get_a20();
+ set_code_success(regs);
+}
+
+static void
+handle_152403(struct bregs *regs)
+{
+ regs->bx = 3;
+ set_code_success(regs);
+}
+
+static void
+handle_1524XX(struct bregs *regs)
+{
+ set_code_unimplemented(regs, RET_EUNSUPPORTED);
+}
+
+static void
+handle_1524(struct bregs *regs)
+{
+ switch (regs->al) {
+ case 0x00: handle_152400(regs); break;
+ case 0x01: handle_152401(regs); break;
+ case 0x02: handle_152402(regs); break;
+ case 0x03: handle_152403(regs); break;
+ default: handle_1524XX(regs); break;
+ }
+}
+
+// removable media eject
+static void
+handle_1552(struct bregs *regs)
+{
+ set_code_success(regs);
+}
+
+static void
+handle_1587(struct bregs *regs)
+{
+ // +++ should probably have descriptor checks
+ // +++ should have exception handlers
+
+ u8 prev_a20_enable = set_a20(1); // enable A20 line
+
+ // 128K max of transfer on 386+ ???
+ // source == destination ???
+
+ // ES:SI points to descriptor table
+ // offset use initially comments
+ // ==============================================
+ // 00..07 Unused zeros Null descriptor
+ // 08..0f GDT zeros filled in by BIOS
+ // 10..17 source ssssssss source of data
+ // 18..1f dest dddddddd destination of data
+ // 20..27 CS zeros filled in by BIOS
+ // 28..2f SS zeros filled in by BIOS
+
+// check for access rights of source & dest here
+
+ // Initialize GDT descriptor
+ u64 *gdt_far = (void*)(regs->si + 0);
+ u16 gdt_seg = regs->es;
+ u32 loc = (u32)MAKE_FLATPTR(gdt_seg, gdt_far);
+ SET_FARVAR(gdt_seg, gdt_far[1], GDT_DATA | GDT_LIMIT((6*sizeof(u64))-1)
+ | GDT_BASE(loc));
+ // Initialize CS descriptor
+ u64 lim = GDT_LIMIT(0x0ffff);
+ if (in_post())
+ lim = GDT_GRANLIMIT(0xffffffff);
+ SET_FARVAR(gdt_seg, gdt_far[4], GDT_CODE | lim | GDT_BASE(BUILD_BIOS_ADDR));
+ // Initialize SS descriptor
+ loc = (u32)MAKE_FLATPTR(GET_SEG(SS), 0);
+ SET_FARVAR(gdt_seg, gdt_far[5], GDT_DATA | lim | GDT_BASE(loc));
+
+ SET_SEG(ES, gdt_seg);
+ u16 count = regs->cx, si = 0, di = 0;
+ asm volatile(
+ // Load new descriptor tables
+ " lgdtw %%es:(1<<3)(%%eax)\n"
+ " lidtw %%cs:pmode_IDT_info\n"
+
+ // Enable protected mode
+ " movl %%cr0, %%eax\n"
+ " orl $" __stringify(CR0_PE) ", %%eax\n"
+ " movl %%eax, %%cr0\n"
+
+ // far jump to flush CPU queue after transition to protected mode
+ " ljmpw $(4<<3), $1f\n"
+
+ // GDT points to valid descriptor table, now load DS, ES
+ "1:movw $(2<<3), %%ax\n" // 2nd descriptor in table, TI=GDT, RPL=00
+ " movw %%ax, %%ds\n"
+ " movw $(3<<3), %%ax\n" // 3rd descriptor in table, TI=GDT, RPL=00
+ " movw %%ax, %%es\n"
+
+ // memcpy CX words using 32bit memcpy if applicable
+ " testw $1, %%cx\n"
+ " jnz 3f\n"
+ " shrw $1, %%cx\n"
+ " rep movsl %%ds:(%%si), %%es:(%%di)\n"
+
+ // Restore DS and ES segment limits to 0xffff
+ "2:movw $(5<<3), %%ax\n" // 5th descriptor in table (SS)
+ " movw %%ax, %%ds\n"
+ " movw %%ax, %%es\n"
+
+ // Disable protected mode
+ " movl %%cr0, %%eax\n"
+ " andl $~" __stringify(CR0_PE) ", %%eax\n"
+ " movl %%eax, %%cr0\n"
+
+ // far jump to flush CPU queue after transition to real mode
+ " ljmpw $" __stringify(SEG_BIOS) ", $4f\n"
+
+ // Slower 16bit copy method
+ "3:rep movsw %%ds:(%%si), %%es:(%%di)\n"
+ " jmp 2b\n"
+
+ // restore IDT to normal real-mode defaults
+ "4:lidtw %%cs:rmode_IDT_info\n"
+
+ // Restore %ds (from %ss)
+ " movw %%ss, %%ax\n"
+ " movw %%ax, %%ds\n"
+ : "+a" (gdt_far), "+c"(count), "+m" (__segment_ES)
+ : "S" (si), "D" (di)
+ : "cc");
+
+ set_a20(prev_a20_enable);
+
+ set_code_success(regs);
+}
+
+// Get the amount of extended memory (above 1M)
+static void
+handle_1588(struct bregs *regs)
+{
+ u32 rs = GET_GLOBAL(LegacyRamSize);
+
+ // According to Ralf Brown's interrupt the limit should be 15M,
+ // but real machines mostly return max. 63M.
+ if (rs > 64*1024*1024)
+ regs->ax = 63 * 1024;
+ else
+ regs->ax = (rs - 1*1024*1024) / 1024;
+ set_success(regs);
+}
+
+// Switch to protected mode
+void VISIBLE16
+handle_1589(struct bregs *regs)
+{
+ debug_enter(regs, DEBUG_HDL_15);
+ set_a20(1);
+
+ pic_reset(regs->bl, regs->bh);
+
+ u64 *gdt_far = (void*)(regs->si + 0);
+ u16 gdt_seg = regs->es;
+ SET_FARVAR(gdt_seg, gdt_far[7], GDT_CODE | GDT_LIMIT(BUILD_BIOS_SIZE-1)
+ | GDT_BASE(BUILD_BIOS_ADDR));
+
+ regs->ds = 3<<3; // 3rd gdt descriptor is %ds
+ regs->es = 4<<3; // 4th gdt descriptor is %es
+ regs->code.seg = 6<<3; // 6th gdt descriptor is %cs
+
+ set_code_success(regs);
+
+ asm volatile(
+ // Load new descriptor tables
+ " lgdtw %%es:(1<<3)(%%si)\n"
+ " lidtw %%es:(2<<3)(%%si)\n"
+
+ // Enable protected mode
+ " movl %%cr0, %%eax\n"
+ " orl $" __stringify(CR0_PE) ", %%eax\n"
+ " movl %%eax, %%cr0\n"
+
+ // far jump to flush CPU queue after transition to protected mode
+ " ljmpw $(7<<3), $1f\n"
+
+ // GDT points to valid descriptor table, now load SS
+ "1:movw $(5<<3), %%ax\n"
+ " movw %%ax, %%ds\n"
+ " movw %%ax, %%ss\n"
+ :
+ : "S"(gdt_far), "m" (__segment_ES)
+ : "eax", "cc");
+}
+
+// Device busy interrupt. Called by Int 16h when no key available
+static void
+handle_1590(struct bregs *regs)
+{
+}
+
+// Interrupt complete. Called by Int 16h when key becomes available
+static void
+handle_1591(struct bregs *regs)
+{
+}
+
+// keyboard intercept
+static void
+handle_154f(struct bregs *regs)
+{
+ set_invalid_silent(regs);
+}
+
+static void
+handle_15c0(struct bregs *regs)
+{
+ regs->es = SEG_BIOS;
+ regs->bx = (u32)&BIOS_CONFIG_TABLE;
+ set_code_success(regs);
+}
+
+static void
+handle_15c1(struct bregs *regs)
+{
+ regs->es = get_ebda_seg();
+ set_success(regs);
+}
+
+static void
+handle_15e801(struct bregs *regs)
+{
+ // my real system sets ax and bx to 0
+ // this is confirmed by Ralph Brown list
+ // but syslinux v1.48 is known to behave
+ // strangely if ax is set to 0
+ // regs.u.r16.ax = 0;
+ // regs.u.r16.bx = 0;
+
+ u32 rs = GET_GLOBAL(LegacyRamSize);
+
+ // Get the amount of extended memory (above 1M)
+ if (rs > 16*1024*1024) {
+ // limit to 15M
+ regs->cx = 15*1024;
+ // Get the amount of extended memory above 16M in 64k blocks
+ regs->dx = (rs - 16*1024*1024) / (64*1024);
+ } else {
+ regs->cx = (rs - 1*1024*1024) / 1024;
+ regs->dx = 0;
+ }
+
+ // Set configured memory equal to extended memory
+ regs->ax = regs->cx;
+ regs->bx = regs->dx;
+
+ set_success(regs);
+}
+
+static void
+handle_15e820(struct bregs *regs)
+{
+ int count = GET_GLOBAL(e820_count);
+ if (regs->edx != 0x534D4150 || regs->bx >= count
+ || regs->ecx < sizeof(e820_list[0])) {
+ set_code_invalid(regs, RET_EUNSUPPORTED);
+ return;
+ }
+
+ memcpy_far(regs->es, (void*)(regs->di+0)
+ , get_global_seg(), &e820_list[regs->bx]
+ , sizeof(e820_list[0]));
+ if (regs->bx == count-1)
+ regs->ebx = 0;
+ else
+ regs->ebx++;
+ regs->eax = 0x534D4150;
+ regs->ecx = sizeof(e820_list[0]);
+ set_success(regs);
+}
+
+static void
+handle_15e8XX(struct bregs *regs)
+{
+ set_code_unimplemented(regs, RET_EUNSUPPORTED);
+}
+
+static void
+handle_15e8(struct bregs *regs)
+{
+ switch (regs->al) {
+ case 0x01: handle_15e801(regs); break;
+ case 0x20: handle_15e820(regs); break;
+ default: handle_15e8XX(regs); break;
+ }
+}
+
+static void
+handle_15XX(struct bregs *regs)
+{
+ set_code_unimplemented(regs, RET_EUNSUPPORTED);
+}
+
+// INT 15h System Services Entry Point
+void VISIBLE16
+handle_15(struct bregs *regs)
+{
+ debug_enter(regs, DEBUG_HDL_15);
+ switch (regs->ah) {
+ case 0x24: handle_1524(regs); break;
+ case 0x4f: handle_154f(regs); break;
+ case 0x52: handle_1552(regs); break;
+ case 0x53: handle_1553(regs); break;
+ case 0x5f: handle_155f(regs); break;
+ case 0x7f: handle_157f(regs); break;
+ case 0x83: handle_1583(regs); break;
+ case 0x86: handle_1586(regs); break;
+ case 0x87: handle_1587(regs); break;
+ case 0x88: handle_1588(regs); break;
+ case 0x90: handle_1590(regs); break;
+ case 0x91: handle_1591(regs); break;
+ case 0xc0: handle_15c0(regs); break;
+ case 0xc1: handle_15c1(regs); break;
+ case 0xc2: handle_15c2(regs); break;
+ case 0xe8: handle_15e8(regs); break;
+ default: handle_15XX(regs); break;
+ }
+}
Code Review / kvmfornfv.git / blobdiff