Hi! Just want to make system shutdown. For this goal I'm review grub sources. And found few usefull functions:
prot_to_real:
/* just in case, set GDT */
lgdt gdtdesc
/* save the protected mode stack */
movl %esp, %eax
movl %eax, protstack
/* get the return address */
movl (%esp), %eax
movl %eax, GRUB_MEMORY_MACHINE_REAL_STACK
/* set up new stack */
movl $GRUB_MEMORY_MACHINE_REAL_STACK, %eax
movl %eax, %esp
movl %eax, %ebp
/* set up segment limits */
movw $GRUB_MEMORY_MACHINE_PSEUDO_REAL_DSEG, %ax
movw %ax, %ds
movw %ax, %es
movw %ax, %fs
movw %ax, %gs
movw %ax, %ss
/* this might be an extra step */
/* jump to a 16 bit segment */
ljmp $GRUB_MEMORY_MACHINE_PSEUDO_REAL_CSEG, $tmpcseg
tmpcseg:
.code16
/* clear the PE bit of CR0 */
movl %cr0, %eax
andl $(~GRUB_MEMORY_MACHINE_CR0_PE_ON), %eax
movl %eax, %cr0
/* flush prefetch queue, reload %cs */
DATA32 ljmp $0, $realcseg
realcseg:
/* we are in real mode now
* set up the real mode segment registers : DS, SS, ES
*/
/* zero %eax */
xorl %eax, %eax
movw %ax, %ds
movw %ax, %es
movw %ax, %fs
movw %ax, %gs
movw %ax, %ss
/* restore interrupts */
sti
/* return on new stack! */
DATA32 ret
.code32
------------------------------------------------------------------------
FUNCTION(grub_halt)
/* see if zero */
testl %eax, %eax
jnz EXT_C(grub_stop)
call prot_to_real
.code16
/* detect APM */
movw $0x5300, %ax
xorw %bx, %bx
int $0x15
jc EXT_C(grub_hard_stop)
/* don't check %bx for buggy BIOSes... */
/* disconnect APM first */
movw $0x5304, %ax
xorw %bx, %bx
int $0x15
/* connect APM */
movw $0x5301, %ax
xorw %bx, %bx
int $0x15
jc EXT_C(grub_hard_stop)
/* set APM protocol level - 1.1 or bust. (this covers APM 1.2 also) */
movw $0x530E, %ax
xorw %bx, %bx
movw $0x0101, %cx
int $0x15
jc EXT_C(grub_hard_stop)
/* set the power state to off */
movw $0x5307, %ax
movw $1, %bx
movw $3, %cx
int $0x15
/* shouldn't reach here */
jmp EXT_C(grub_hard_stop)
.code32
When I'm trying switch to real mode - as result system goes down. Need some
explanation why. Tnx.
Best regards, Taras.
poweroff.patch
Description: Binary data
------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________ SharpOS-Developers mailing list SharpOS-Developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sharpos-developers
