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-rw-r--r--util/x86emu/x86.c230
1 files changed, 230 insertions, 0 deletions
diff --git a/util/x86emu/x86.c b/util/x86emu/x86.c
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+++ b/util/x86emu/x86.c
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+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2009 coresystems GmbH
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <device/pci.h>
+#include <string.h>
+
+#ifdef CONFIG_COREBOOT_V2
+#include <arch/io.h>
+#include <console/console.h>
+#define printk(x...) do_printk(x)
+#else
+#include <console.h>
+#endif
+
+#define REALMODE_BASE ((void *)0x500)
+
+struct realmode_idt {
+ u16 offset, cs;
+};
+
+struct eregs {
+ uint32_t eax, ecx, edx, ebx, esp, ebp, esi, edi;
+ uint32_t vector;
+ uint32_t error_code;
+ uint32_t eip;
+ uint32_t cs;
+ uint32_t eflags;
+};
+
+void x86_exception(struct eregs *info);
+
+extern unsigned char __idt_handler, __idt_handler_size;
+extern unsigned char __realmode_code, __realmode_code_size;
+extern unsigned char __run_optionrom, __run_interrupt;
+
+void (*run_optionrom)(u32 devfn) = (void *)&__run_optionrom;
+void (*vga_enable_console)(void) = (void *)&__run_interrupt;
+
+int (*intXX_handler[256])(struct eregs *regs) = { NULL };
+
+static int intXX_exception_handler(struct eregs *regs)
+{
+ printk(BIOS_INFO, "Oops, exception %d while executing option rom\n",
+ regs->vector);
+ x86_exception(regs); // Call coreboot exception handler
+
+ return 0; // Never returns?
+}
+
+static int intXX_unknown_handler(struct eregs *regs)
+{
+ printk(BIOS_INFO, "Unsupported software interrupt #0x%x\n",
+ regs->vector);
+
+ return -1;
+}
+
+int int12_handler(struct eregs *regs);
+int int15_handler(struct eregs *regs);
+int int1a_handler(struct eregs *regs);
+
+static void setup_interrupt_handlers(void)
+{
+ int i;
+
+ /* The first 16 intXX functions are not BIOS services,
+ * but the CPU-generated exceptions ("hardware interrupts")
+ */
+ for (i = 0; i < 0x10; i++)
+ intXX_handler[i] = &intXX_exception_handler;
+
+ /* Mark all other intXX calls as unknown first */
+ for (i = 0x10; i < 0x100; i++)
+ intXX_handler[i] = &intXX_unknown_handler;
+
+ /* Now set the default functions that are actually
+ * needed to initialize the option roms. This is very
+ * slick, as it allows us to implement mainboard specific
+ * interrupt handlers, such as the int15
+ */
+ intXX_handler[0x12] = &int12_handler;
+ intXX_handler[0x15] = &int15_handler;
+ intXX_handler[0x1a] = &int1a_handler;
+}
+
+static void write_idt_stub(void *target, u8 intnum)
+{
+ unsigned char *codeptr;
+ codeptr = (unsigned char *) target;
+ memcpy(codeptr, &__idt_handler, (size_t)&__idt_handler_size);
+ codeptr[3] = intnum; /* modify int# in the code stub. */
+}
+
+static void setup_realmode_idt(void)
+{
+ struct realmode_idt *idts = (struct realmode_idt *) 0;
+ int i;
+
+ /* Copy IDT stub code for each interrupt. This might seem wasteful
+ * but it is really simple
+ */
+ for (i = 0; i < 256; i++) {
+ idts[i].cs = 0;
+ idts[i].offset = 0x1000 + (i * (u32)&__idt_handler_size);
+ write_idt_stub((void *)((u32 )idts[i].offset), i);
+ }
+
+ /* Many option ROMs use the hard coded interrupt entry points in the
+ * system bios. So install them at the known locations.
+ * Only need int10 so far.
+ */
+
+ /* int42 is the relocated int10 */
+ write_idt_stub((void *)0xff065, 0x42);
+}
+
+void run_bios(struct device *dev, unsigned long addr)
+{
+ int i;
+
+ /* clear vga bios data area */
+ for (i = 0x400; i < 0x500; i++) {
+ *(unsigned char *) i = 0;
+ }
+
+ /* Set up C interrupt handlers */
+ setup_interrupt_handlers();
+
+ /* Setting up realmode IDT */
+ setup_realmode_idt();
+
+ memcpy(REALMODE_BASE, &__realmode_code, (size_t)&__realmode_code_size);
+ printk(BIOS_SPEW, "Real mode stub @%p: %d bytes\n", REALMODE_BASE,
+ (u32)&__realmode_code_size);
+
+ printk(BIOS_DEBUG, "Calling Option ROM...\n");
+ run_optionrom((dev->bus->secondary << 8) | dev->path.pci.devfn);
+ printk(BIOS_DEBUG, "... Option ROM returned.\n");
+}
+
+int __attribute__((regparm(0))) interrupt_handler(u32 intnumber,
+ u32 gsfs, u32 dses,
+ u32 edi, u32 esi,
+ u32 ebp, u32 esp,
+ u32 ebx, u32 edx,
+ u32 ecx, u32 eax,
+ u32 cs_ip, u16 stackflags)
+{
+ u32 ip;
+ u32 cs;
+ u32 flags;
+ int ret = -1;
+ struct eregs reg_info;
+
+ ip = cs_ip & 0xffff;
+ cs = cs_ip >> 16;
+ flags = stackflags;
+
+ printk(BIOS_DEBUG, "oprom: INT# 0x%x\n", intnumber);
+ printk(BIOS_DEBUG, "oprom: eax: %08x ebx: %08x ecx: %08x edx: %08x\n",
+ eax, ebx, ecx, edx);
+ printk(BIOS_DEBUG, "oprom: ebp: %08x esp: %08x edi: %08x esi: %08x\n",
+ ebp, esp, edi, esi);
+ printk(BIOS_DEBUG, "oprom: ip: %04x cs: %04x flags: %08x\n",
+ ip, cs, flags);
+
+ // Fetch arguments from the stack and put them into
+ // a structure that we want to pass on to our sub interrupt
+ // handlers.
+ reg_info = (struct eregs) {
+ .eax=eax,
+ .ecx=ecx,
+ .edx=edx,
+ .ebx=ebx,
+ .esp=esp,
+ .ebp=ebp,
+ .esi=esi,
+ .edi=edi,
+ .vector=intnumber,
+ .error_code=0, // ??
+ .eip=ip,
+ .cs=cs,
+ .eflags=flags // ??
+ };
+
+ // Call the interrupt handler for this int#
+ ret = intXX_handler[intnumber](&reg_info);
+
+ // Put registers back on the stack. The assembler code
+ // will later pop them.
+ // What happens here is that we force (volatile!) changing
+ // the values of the parameters of this function. We do this
+ // because we know that they stay alive on the stack after
+ // we leave this function. Don't say this is bollocks.
+ *(volatile u32 *)&eax = reg_info.eax;
+ *(volatile u32 *)&ecx = reg_info.ecx;
+ *(volatile u32 *)&edx = reg_info.edx;
+ *(volatile u32 *)&ebx = reg_info.ebx;
+ *(volatile u32 *)&esi = reg_info.esi;
+ *(volatile u32 *)&edi = reg_info.edi;
+ flags = reg_info.eflags;
+
+ /* Pass errors back to our caller via the CARRY flag */
+ if (ret) {
+ printk(BIOS_DEBUG,"error!\n");
+ flags |= 1; // error: set carry
+ }else{
+ flags &= ~1; // no error: clear carry
+ }
+ *(volatile u16 *)&stackflags = flags;
+
+ return ret;
+}
+