84 lines
1.5 KiB
C++
84 lines
1.5 KiB
C++
/*
|
|
SparrowOS runs exclusively in ring 0.
|
|
Ring 0 is part of the $LK,"Constitution","FI:::/SparrowOS/Doc/Constitution.TXT.Z"$.
|
|
This demo is for you to play around
|
|
with ring 3. SparrowOS is for
|
|
recreational programming, after all.
|
|
|
|
This redirects the general protection
|
|
fault, switches to ring 3, and generates
|
|
a fault to switch back.
|
|
*/
|
|
|
|
U8 *old_stk,*new_rip;
|
|
|
|
asm {
|
|
IMPORT SYS_PROGRESS1,old_stk,new_rip;
|
|
TO_RING0:: //Set to handle general protection 0xD fault temporarily.
|
|
INC U64 [SYS_PROGRESS1]
|
|
PUSH U32 GDT_ZERO_DS_SEL //STKSEG
|
|
MOV RAX,U64 [&old_stk]
|
|
PUSH RAX
|
|
PUSH U32 0 //FLAGS--interrupts off
|
|
PUSH U32 GDT_CS64_SEL
|
|
MOV RAX,U64 [&new_rip]
|
|
PUSH RAX
|
|
IRET
|
|
}
|
|
|
|
|
|
|
|
U0 Ring3Demo()
|
|
{
|
|
U8 *old_pf;
|
|
"Progress1 Before:%X\n",progress1;
|
|
Cli;
|
|
old_pf=IntEntrySet(0x0D,TO_RING0,0,IDTET_TRAP,0);
|
|
|
|
TSSBusy(Gs->tss->tr_ring3,OFF);
|
|
SetRAX(Gs->tss->tr_ring3+3);
|
|
asm { LTR AX}
|
|
|
|
|
|
asm {
|
|
IMPORT SYS_PROGRESS1,old_stk,new_rip;
|
|
|
|
MOV U64 [&old_stk],RSP
|
|
|
|
LEA RAX,[R3_CALLBACK]
|
|
MOV U64 [&new_rip],RAX
|
|
|
|
MOV AX,GDT_ZERO_DS_RING3_SEL+3
|
|
MOV DS,AX
|
|
MOV ES,AX
|
|
|
|
PUSH U32 GDT_ZERO_DS_RING3_SEL+3 //STKSEG
|
|
PUSH U64 [&old_stk]
|
|
PUSH U32 0 //FLAGS--interrupts off
|
|
PUSH U32 GDT_CS64_RING3_SEL+3
|
|
LEA RAX,[R3_START]
|
|
PUSH RAX
|
|
IRET
|
|
|
|
R3_START:
|
|
INC U64 [SYS_PROGRESS1]
|
|
CLI //This causes general protection fault #13
|
|
|
|
R3_CALLBACK:
|
|
MOV AX,GDT_ZERO_DS_SEL
|
|
MOV DS,AX
|
|
MOV ES,AX
|
|
}
|
|
|
|
TSSBusy(Gs->tss->tr,OFF);
|
|
SetRAX(Gs->tss->tr);
|
|
asm { LTR AX}
|
|
|
|
IntEntrySet(0x0D,old_pf,0,IDTET_IRQ,0);
|
|
Sti;
|
|
"Progress1 After :%X\n",progress1;
|
|
}
|
|
|
|
|
|
Ring3Demo;
|