templeos-info/public/Wb/Demo/Lectures/Ring3.HC

76 lines
1.4 KiB
HolyC
Executable File

/*TempleOS runs exclusively in ring 0.
Ring 0 is part of the $LK,"Charter",A="FI:::/Doc/Charter.DD"$.
This demo is for you to play around
with ring 3. TempleOS 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 {
INT_TO_RING0:: //Set to handle general protection 0xD fault temporarily.
INC U64 [SYS_PROGRESS1]
PUSH U32 CGDT.ds //STKSEG
MOV RAX,U64 [&old_stk]
PUSH RAX
PUSH U32 0 //FLAGS--interrupts off
PUSH U32 CGDT.cs64
MOV RAX,U64 [&new_rip]
PUSH RAX
IRET
}
U0 Ring3Demo()
{
U8 *old_vect;
"Progress1 Before:%X\n",progress1;
CLI
old_vect=IntEntrySet(0x0D,INT_TO_RING0,IDTET_TRAP,0);
TSSBusy(Gs->tss->tr_ring3,OFF);
SetRAX(Gs->tss->tr_ring3+3);
LTR AX
asm {
MOV U64 [&old_stk],RSP
LEA RAX,[R3_CALLBACK]
MOV U64 [&new_rip],RAX
MOV AX,CGDT.ds_ring3+3
MOV DS,AX
MOV ES,AX
PUSH U32 CGDT.ds_ring3+3 //STKSEG
PUSH U64 [&old_stk]
PUSH U32 0 //FLAGS--interrupts off
PUSH U32 CGDT.cs64_ring3+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,CGDT.ds
MOV DS,AX
MOV ES,AX
}
TSSBusy(Gs->tss->tr,OFF);
SetRAX(Gs->tss->tr);
LTR AX
IntEntrySet(0x0D,old_vect,IDTET_IRQ,0);
STI
"Progress1 After :%X\n",progress1;
}
Ring3Demo;