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There are some problems with the way these interrrupts were

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managed. First, the CLI erases any knowledge of whether interrupts 
were enabled or disabled. Second, the STI works badly on qemu; we 
get an immediate INT #0 as soon as the STI happens.

This spurious interrupt doesn't happen on real hardware (YET!)but, 
that said, I don't think this code should be doing cli and sti. I 
can't see a reason to enable interrupts at this point in coreboot.

This change fixes the observed qemu failures.

Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Acked-by: Stefan Reinauer <stepan@coresystems.de>



git-svn-id: svn://coreboot.org/repository/coreboot-v3@1172 f3766cd6-281f-0410-b1cd-43a5c92072e9
This commit is contained in:
Ronald G. Minnich 2009-06-09 11:14:26 +00:00
commit ce314b3f02
1 changed files with 1 additions and 49 deletions
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50
util/x86emu/x86_asm.S
View file

@ -71,11 +71,6 @@ __run_optionrom = RELOCATED(.)
// FIXME: Should this function be called with regparm=0?
movl 8(%ebp), %ecx
/* Clear interrupts before making a
* transition to Real Mode
*/
cli
/* Activate the right segment descriptor real mode. */
ljmp $0x28, $RELOCATED(1f)
1:
@ -111,14 +106,11 @@ __run_optionrom = RELOCATED(.)
movl $0x1000, %eax
movl %eax, %esp
/* Load our 16 it idt */
/* Load our 16 bit idt */
xor %ax, %ax
mov %ax, %ds
lidt __realmode_idt
/* All critical work is done, allow interrupts again */
sti
/* Set all segments to 0x0000, ds to 0x0040 */
mov %ax, %es
mov %ax, %fs
@ -133,11 +125,6 @@ __run_optionrom = RELOCATED(.)
lcall $0xc000, $0x0003
/* ************************************ */
/* Clear interrupts before making a
* transition to Protected Mode
*/
cli
/* If we got here, just about done.
* Need to get back to protected mode
*/
@ -161,9 +148,6 @@ __run_optionrom = RELOCATED(.)
/* restore proper idt */
lidt idtarg
/* All critical work is done, allow interrupts again */
sti
/* and exit */
mov __stack, %esp
popal
@ -179,11 +163,6 @@ __run_interrupt = RELOCATED(.)
mov %esp, __stack
/* Clear interrupts before making a
* transition to Real Mode
*/
cli
/* This configures CS properly for real mode. */
ljmp $0x28, $RELOCATED(1f)
1:
@ -228,9 +207,6 @@ __run_interrupt = RELOCATED(.)
mov %ax, %ds
lidt __realmode_idt
/* All critical work is done, allow interrupts again */
sti
/* Set all segments to 0x0000 */
mov %ax, %ds
mov %ax, %es
@ -250,11 +226,6 @@ __run_interrupt = RELOCATED(.)
movw $0, %di
int $0x10
/* Clear interrupts before making a
* transition to Protected Mode
*/
cli
/* Ok, the job is done, now go back to protected mode coreboot */
movl %cr0, %eax
orl $PE, %eax
@ -274,9 +245,6 @@ __run_interrupt = RELOCATED(.)
/* restore coreboot's 32-bit IDT */
lidt idtarg
/* All critical work is done, allow interrupts again */
sti
/* Exit */
mov __stack, %esp
popal
@ -299,11 +267,6 @@ __interrupt_handler_16bit = RELOCATED(.)
andl $0xff, %eax
pushl %eax /* ... and make it the first parameter */
/* Clear interrupts before making a
* transition to Protected Mode
*/
cli
/* Switch to protected mode */
movl %cr0, %eax
orl $PE, %eax
@ -322,9 +285,6 @@ __interrupt_handler_16bit = RELOCATED(.)
lidt idtarg
/* All critical work is done, allow interrupts again */
sti
/* Call the C interrupt handler */
movl $interrupt_handler, %eax
call *%eax
@ -344,11 +304,6 @@ __interrupt_handler_16bit = RELOCATED(.)
mov %ax, %gs
mov %ax, %ss
/* Clear interrupts before making a
* transition to Real Mode
*/
cli
/* Disable Protected Mode */
movl %cr0, %eax
andl $~PE, %eax
@ -366,9 +321,6 @@ __interrupt_handler_16bit = RELOCATED(.)
mov %ax, %ds
lidt __realmode_idt
/* All critical work is done, allow interrupts again */
sti
/* Set up our segment registers to segment 0x0000 */
mov %ax, %es
mov %ax, %fs