Change real mode API to allow passing intXX number or entry point and

some register values from C. 

This theoretically fixes non-vga option roms, but it also allows to use
the same assembler code for option roms and vsm.
It will also make using the bootsplash without yabel a lot easier.

Factor out and improve BDA setup, do some rom segment setup for those
option roms that need it. 

Don't call the coreboot exception handler if an exception occurs in real
mode. It's only partly usable, but mainly the Kontron 986LCD-M (and other
i945GM boards) choke on an exception #6 (invalid opcode). This particular
issue is not introduced by the changes in this patch but has been around
for quite a while at least.

Signed-off-by: Stefan Reinauer <stepan@coresystems.de>
Acked-by: Patrick Georgi <patrick.georgi@coresystems.de>



git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5543 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

1 files changed, 71 insertions, 16 deletions

diff --git a/src/devices/oprom/x86.c b/src/devices/oprom/x86.c
index 4d9604a581..42267faa5f 100644
--- a/src/devices/oprom/x86.c
+++ b/src/devices/oprom/x86.c
@@ -34,12 +34,45 @@ struct realmode_idt {
 
 void x86_exception(struct eregs *info);
 
+/* From x86_asm.S */
 extern unsigned char __idt_handler, __idt_handler_size;
 extern unsigned char __realmode_code, __realmode_code_size;
-extern unsigned char __run_optionrom, __run_interrupt;
+extern unsigned char __realmode_call, __realmode_interrupt;
 
-void (*run_optionrom)(u32 devfn) __attribute__((regparm(0))) = (void *)&__run_optionrom;
-void (*vga_enable_console)(void) __attribute__((regparm(0))) = (void *)&__run_interrupt;
+void (*realmode_call)(u32 addr, u32 eax, u32 ebx, u32 ecx, u32 edx,
+		u32 esi, u32 edi) __attribute__((regparm(0))) = (void *)&__realmode_call;
+
+void (*realmode_interrupt)(u32 intno, u32 eax, u32 ebx, u32 ecx, u32 edx, 
+		u32 esi, u32 edi) __attribute__((regparm(0))) = (void *)&__realmode_interrupt;
+
+#define FAKE_MEMORY_SIZE (1024*1024) // only 1MB
+#define INITIAL_EBDA_SEGMENT 0xF600
+#define INITIAL_EBDA_SIZE 0x400
+
+static void setup_bda(void)
+{
+	/* clear BIOS DATA AREA */
+	memset((void *)0x400, 0, 0x200);
+
+	write16(0x413, FAKE_MEMORY_SIZE / 1024);
+	write16(0x40e, INITIAL_EBDA_SEGMENT);
+
+	/* Set up EBDA */
+	memset((void *)(INITIAL_EBDA_SEGMENT << 4), 0, INITIAL_EBDA_SIZE);
+	write16((INITIAL_EBDA_SEGMENT << 4) + 0x0, INITIAL_EBDA_SIZE / 1024);
+}
+
+static void setup_rombios(void)
+{
+	const char date[] = "06/11/99";
+	memcpy((void *)0xffff5, &date, 8);
+
+	const char ident[] = "PCI_ISA";
+	memcpy((void *)0xfffd9, &ident, 7);
+
+	/* system model: IBM-AT */
+	write8(0xffffe, 0xfc);
+}
 
 int (*intXX_handler[256])(struct eregs *regs) = { NULL };
 
@@ -47,7 +80,12 @@ static int intXX_exception_handler(struct eregs *regs)
 {
 	printk(BIOS_INFO, "Oops, exception %d while executing option rom\n",
 			regs->vector);
+#if 0
+	// Odd: The i945GM VGA oprom chokes on a pushl %eax and will
+	// die with an exception #6 if we run the coreboot exception 
+	// handler. Just continue, as it executes fine.
 	x86_exception(regs);	// Call coreboot exception handler
+#endif
 
 	return 0;		// Never returns?
 }
@@ -138,20 +176,38 @@ static void setup_realmode_idt(void)
 
 	/* int42 is the relocated int10 */
 	write_idt_stub((void *)0xff065, 0x42);
-
-	/* VIA's VBIOS calls f000:f859 instead of int15 */
+	/* BIOS Int 11 Handler F000:F84D */
+	write_idt_stub((void *)0xff84d, 0x11);
+	/* BIOS Int 12 Handler F000:F841 */
+	write_idt_stub((void *)0xff841, 0x12);
+	/* BIOS Int 13 Handler F000:EC59 */
+	write_idt_stub((void *)0xfec59, 0x13);
+	/* BIOS Int 14 Handler F000:E739 */
+	write_idt_stub((void *)0xfe739, 0x14);
+	/* BIOS Int 15 Handler F000:F859 */
 	write_idt_stub((void *)0xff859, 0x15);
+	/* BIOS Int 16 Handler F000:E82E */
+	write_idt_stub((void *)0xfe82e, 0x16);
+	/* BIOS Int 17 Handler F000:EFD2 */
+	write_idt_stub((void *)0xfefd2, 0x17);
+	/* ROM BIOS Int 1A Handler F000:FE6E */
+	write_idt_stub((void *)0xffe6e, 0x1a);
 }
 
 void run_bios(struct device *dev, unsigned long addr)
 {
-	/* clear vga bios data area */
-	memset((void *)0x400, 0, 0x200);
+	u32 num_dev = (dev->bus->secondary << 8) | dev->path.pci.devfn;
+
+	/* Set up BIOS Data Area */
+	setup_bda();
+
+	/* Set up some legacy information in the F segment */
+	setup_rombios();
 
 	/* Set up C interrupt handlers */
 	setup_interrupt_handlers();
 
-	/* Setting up realmode IDT */
+	/* Set up real-mode IDT */
 	setup_realmode_idt();
 
 	memcpy(REALMODE_BASE, &__realmode_code, (size_t)&__realmode_code_size);
@@ -159,7 +215,9 @@ void run_bios(struct device *dev, unsigned long addr)
 			(u32)&__realmode_code_size);
 
 	printk(BIOS_DEBUG, "Calling Option ROM...\n");
-	run_optionrom((dev->bus->secondary << 8) | dev->path.pci.devfn);
+	/* TODO ES:DI Pointer to System BIOS PnP Installation Check Structure */
+	/* Option ROM entry point is at OPROM start + 3 */
+	realmode_call(addr + 0x0003, num_dev, 0xffff, 0x0000, 0xffff, 0x0, 0x0);
 	printk(BIOS_DEBUG, "... Option ROM returned.\n");
 }
 
@@ -168,9 +226,6 @@ void run_bios(struct device *dev, unsigned long addr)
 #include <cpu/amd/vr.h>
 #include <cbfs.h>
 
-extern unsigned char __run_vsa;
-void (*run_vsa)(u32 smm, u32 sysmem) __attribute__((regparm(0))) = (void *)&__run_vsa;
-
 #define VSA2_BUFFER		0x60000
 #define VSA2_ENTRY_POINT	0x60020
 
@@ -198,9 +253,6 @@ void do_vsmbios(void)
 {
 	printk(BIOS_DEBUG, "Preparing for VSA...\n");
 
-	/* clear bios data area */
-	memset((void *)0x400, 0, 0x200);
-
 	/* Set up C interrupt handlers */
 	setup_interrupt_handlers();
 
@@ -229,8 +281,11 @@ void do_vsmbios(void)
 	}
 
 	printk(BIOS_DEBUG, "Calling VSA module...\n");
+
 	/* ECX gets SMM, EDX gets SYSMEM */
-	run_vsa(MSR_GLIU0_SMM, MSR_GLIU0_SYSMEM);
+	realmode_call(VSA2_ENTRY_POINT, 0x0, 0x0, MSR_GLIU0_SMM, 
+			MSR_GLIU0_SYSMEM, 0x0, 0x0);
+
 	printk(BIOS_DEBUG, "... VSA module returned.\n");
 
 	/* Restart timer 1 */