1 ; AcessOS Microkernel Version
6 KERNEL_BASE equ 0xC0000000
8 KSTACK_USERSTATE_SIZE equ (4+8+1+5)*4 ; SRegs, GPRegs, CPU, IRET
12 [extern giMP_TimerCount]
13 [extern gpMP_LocalAPIC]
15 [global SetAPICTimerCount]
29 mov eax, [gpMP_LocalAPIC]
33 mov DWORD [eax+0x380], 0xFFFFFFFF ; Set Initial Count
34 mov DWORD [eax+0x320], 0x000000F0 ; Enable the timer on IVT#0xEF (One Shot)
41 mov DWORD [giMP_TimerCount], ecx
43 mov DWORD [eax+0x320], 0x000100EF
44 mov DWORD [eax+0x380], 0
46 ; Update Timer IRQ to the IRQ code
47 mov eax, SchedulerBase
49 mov DWORD [Isr240.jmp+1], eax
51 ;xchg bx, bx ; MAGIC BREAK
62 ; No Error code / int num
68 [extern Proc_Scheduler]
69 [global SchedulerBase]
78 push eax ; Debug Register 0, Current Thread
89 push eax ; Push as argument
96 add esp, 4 ; Remove Argument
104 out 0x20, al ; ACK IRQ
109 mov eax, DWORD [gpMP_LocalAPIC]
110 mov DWORD [eax+0x0B0], 0
113 pop eax ; Debug Register 0, Current Thread
123 ; No Error code / int num
127 [extern Threads_Exit]
130 ; Call Proc_Clone with Flags=0
135 add esp, 8 ; Remove arguments from stack
140 ; In child, so now set up stack frame
141 mov ebx, [esp+4] ; Child Function
142 mov edx, [esp+8] ; Argument
147 push 0 ; Kill this thread
148 call Threads_Exit ; Kill Thread
153 ; void Proc_ReturnToUser(void *Method, Uint Parameter)
154 ; Calls a user fault handler
156 [global Proc_ReturnToUser]
157 [extern Proc_GetCurThread]
161 ; [EBP+4]: handler to use
164 call Proc_GetCurThread
166 ; EAX is the current thread
168 mov eax, [ebx+12*4] ; Get Kernel Stack
169 sub eax, KSTACK_USERSTATE_SIZE
172 ; NOTE: This can cause corruption if the signal happens while the user
173 ; has called a kernel operation.
174 ; Good thing this can only be called on a user fault.
179 mov edx, [eax+KSTACK_USERSTATE_SIZE-12] ; User ESP is at top of kstack - 3*4
185 test BYTE [0xFC3F0000+ecx*4], 1
191 test BYTE [0xFC000000+ecx*4], 1
200 test BYTE [0xFC3F0000+ecx*4], 1
206 test BYTE [0xFC000000+ecx*4], 1
209 ; Get and alter User SP
211 mov edx, [ebp+8] ; Get parameter
212 mov [edi+4], edx ; save to user stack
213 mov [edi], DWORD User_Syscall_RetAndExit ; Return Address
215 ; Restore Segment Registers
224 push 0x202 ; EFLAGS (IP and Rsvd)
226 mov eax, [ebp+4] ; Method to call
231 ; Just kill the bleeding thing
232 ; (I know it calls int 0xAC in kernel mode, but meh)
240 GetCPUNum: ; TODO: Store in debug registers
247 ; Usermode code exported by the kernel
249 ; Export a place for the user to jump to to call a syscall
250 ; - Allows the kernel to change the method easily
252 xchg bx, bx ; MAGIC BREAKPOINT
255 ; A place to return to and exit
256 User_Syscall_RetAndExit:
258 call User_Syscall_Exit