[bits 32]
+%define SAVEFLAG_FPU 0x1
+
KERNEL_BASE equ 0xC0000000
KSTACK_USERSTATE_SIZE equ (4+8+1+5)*4 ; SRegs, GPRegs, CPU, IRET
[section .text]
+
+[global NewTaskHeader]
+NewTaskHeader:
+ mov eax, [esp]
+ mov dr0, eax
+
+ mov eax, [esp+4]
+ add esp, 12 ; Thread, Function, Arg Count
+ call eax
+
+ push eax ; Ret val
+ push 0 ; 0 = This Thread
+ call Threads_Exit
+
+[extern MM_Clone]
+[global Proc_CloneInt]
+Proc_CloneInt:
+ pusha
+ ; Save RSP
+ mov eax, [esp+0x20+4]
+ mov [eax], esp
+ call MM_Clone
+ ; Save CR3
+ mov esi, [esp+0x20+8]
+ mov [esi], eax
+ ; Undo the pusha
+ add esp, 0x20
+ mov eax, .newTask
+ ret
+.newTask:
+ popa
+ xor eax, eax
+ ret
+
+[global SwitchTasks]
+; + 4 = New RSP
+; + 8 = Old RSP save loc
+; +12 = New RIP
+; +16 = Old RIP save loc
+; +20 = CR3
+SwitchTasks:
+ pusha
+
+ ; Old IP
+ mov eax, [esp+0x20+16]
+ test eax, eax
+ jz .nosave
+ mov DWORD [eax], .restore
+ ; Old SP
+ mov eax, [esp+0x20+8]
+ mov [eax], esp
+
+.nosave:
+ mov ecx, [esp+0x20+12] ; New IP
+ mov eax, [esp+0x20+20] ; New CR3
+ mov esp, [esp+0x20+ 4] ; New SP
+
+ test eax, eax
+ jz .setState
+ mov cr3, eax
+ invlpg [esp]
+ invlpg [esp+0x1000]
+.setState:
+ jmp ecx
+
+.restore:
+ popa
+ xor eax, eax
+ ret
+
+[global Proc_InitialiseSSE]
+Proc_InitialiseSSE:
+ mov eax, cr4
+ or eax, (1 << 9)|(1 << 10) ; Set OSFXSR and OSXMMEXCPT
+ mov cr4, eax
+ mov eax, cr0
+ and ax, ~(1 << 2) ; Clear EM
+ or eax, (1 << 1) ; Set MP
+ mov eax, cr0
+ ret
+[global Proc_DisableSSE]
+Proc_DisableSSE:
+ mov eax, cr0
+ or ax, 1 << 3 ; Set TS
+ mov cr0, eax
+ ret
+[global Proc_EnableSSE]
+Proc_EnableSSE:
+ mov eax, cr0
+ and ax, ~(1 << 3) ; Clear TS
+ mov cr0, eax
+ ret
+
+[global Proc_SaveSSE]
+Proc_SaveSSE:
+ mov eax, [esp+4]
+ fxsave [eax]
+ ret
+[global Proc_RestoreSSE]
+Proc_RestoreSSE:
+ mov eax, [esp+4]
+ fxrstor [eax]
+ ret
+
+%if USE_MP
[extern giMP_TimerCount]
[extern gpMP_LocalAPIC]
-[extern Isr240]
+[extern Isr240.jmp]
[global SetAPICTimerCount]
SetAPICTimerCount:
pusha
mov eax, [gpMP_LocalAPIC]
mov ecx, [eax+0x320]
- test ecx, 0x0001000
+ test ecx, 0x00010000
jz .setTime
mov DWORD [eax+0x380], 0xFFFFFFFF ; Set Initial Count
mov DWORD [eax+0x320], 0x000000F0 ; Enable the timer on IVT#0xEF (One Shot)
sub ecx, [eax+0x390]
mov DWORD [giMP_TimerCount], ecx
; Disable APIC Timer
- mov DWORD [eax+0x320], 0x00010000
+ mov DWORD [eax+0x320], 0x000100EF
+ mov DWORD [eax+0x380], 0
; Update Timer IRQ to the IRQ code
mov eax, SchedulerBase
- sub eax, Isr240+5+5+1
- mov DWORD [Isr240+5+5+1], eax
+ sub eax, Isr240.jmp+5
+ mov DWORD [Isr240.jmp+1], eax
+ ;xchg bx, bx ; MAGIC BREAK
.ret:
mov dx, 0x20
mov al, 0x20
out dx, al ; ACK IRQ
+ pop gs
+ pop fs
+ pop es
+ pop ds
popa
- add esp, 4 ; CPU ID
- ; No Error code / int num
+ add esp, 8 ; CPU ID / Error Code
iret
-
+%endif
; --------------
; Task Scheduler
; --------------
push fs
push gs
+ pushf
+ and BYTE [esp+1], 0xFE ; Clear Trap Flag
+ popf
+
+ mov eax, dr0
+ push eax ; Debug Register 0, Current Thread
+
mov ax, 0x10
mov ds, ax
mov es, ax
mov fs, ax
mov gs, ax
+ %if USE_MP
call GetCPUNum
+ mov ebx, eax
push eax ; Push as argument
+ %else
+ push 0
+ %endif
call Proc_Scheduler
+[global scheduler_return]
+scheduler_return: ; Used by some hackery in Proc_DumpThreadCPUState
- add esp, 4 ; Remove Argument
+ add esp, 4 ; Remove CPU Number (thread is poped later)
+
+ %if USE_MP
+ test ebx, ebx
+ jnz .sendEOI
+ %endif
+ mov al, 0x20
+ out 0x20, al ; ACK IRQ
+ %if USE_MP
+ jmp .ret
+
+.sendEOI:
+ mov eax, DWORD [gpMP_LocalAPIC]
+ mov DWORD [eax+0x0B0], 0
+ %endif
+.ret:
+ pop eax ; Debug Register 0, Current Thread
+ mov dr0, eax
+
pop gs
pop fs
pop es
pop ds
-
- mov dx, 0x20
- mov al, 0x20
- out dx, al ; ACK IRQ
+
popa
- add esp, 4 ; CPU ID
+ add esp, 4*2 ; CPU ID + Dummy error code
; No Error code / int num
iret
SpawnTask:
; Call Proc_Clone with Flags=0
xor eax, eax
- push eax
+; push eax
push eax
call Proc_Clone
add esp, 8 ; Remove arguments from stack
; In child, so now set up stack frame
mov ebx, [esp+4] ; Child Function
mov edx, [esp+8] ; Argument
- ; Child
+ ; Child Function
push edx ; Argument
call ebx ; Function
+ ; Kill thread once done
push eax ; Exit Code
push 0 ; Kill this thread
call Threads_Exit ; Kill Thread
.parent:
ret
-;
+; void Proc_ReturnToUser(void *Method, Uint Parameter, tVAddr KernelStack)
; Calls a user fault handler
;
[global Proc_ReturnToUser]
[extern Proc_GetCurThread]
Proc_ReturnToUser:
- ; EBP is the handler to use
-
- call Proc_GetCurThread
+ push ebp
+ mov ebp, esp
+ ; [EBP+8]: handler to use
+ ; [EBP+12]: parameter
+ ; [EBP+16]: kernel stack top
- ; EAX is the current thread
- mov ebx, eax
- mov eax, [ebx+40] ; Get Kernel Stack
+ ; Get kernel stack
+ mov eax, [ebp+16]
sub eax, KSTACK_USERSTATE_SIZE
;
; Validate user ESP
; - Page Table
mov edx, [eax+KSTACK_USERSTATE_SIZE-12] ; User ESP is at top of kstack - 3*4
- %if USE_PAE
- %error PAE Support
- %else
mov ecx, edx
shr ecx, 22
test BYTE [0xFC3F0000+ecx*4], 1
jnz .justKillIt
- %endif
; - Page
mov ecx, edx
shr ecx, 12
; Adjust
sub edx, 8
; - Page Table
- %if USE_PAE
- %else
mov ecx, edx
shr ecx, 22
test BYTE [0xFC3F0000+ecx*4], 1
jnz .justKillIt
- %endif
; - Page
mov ecx, edx
shr ecx, 12
jnz .justKillIt
; Get and alter User SP
- mov ecx, edx
- mov edx, [ebx+60] ; Get Signal Number from TCB
- mov [ecx+4], edx ; Parameter (Signal/Error Number)
- mov [ecx], DWORD User_Syscall_RetAndExit ; Return Address
+ mov edi, edx
+ mov edx, [ebp+12] ; Get parameter
+ mov [edi+4], edx ; save to user stack
+ mov [edi], DWORD User_Syscall_RetAndExit ; Return Address
; Restore Segment Registers
mov ax, 0x23
mov gs, ax
push 0x23 ; SS
- push ecx ; ESP
+ push edi ; ESP
push 0x202 ; EFLAGS (IP and Rsvd)
push 0x1B ; CS
- push ebp ; EIP
+ mov eax, [ebp+8] ; Method to call
+ push eax ; EIP
iret
.justKillIt:
xor eax, eax
xor ebx, ebx
- dec ebx
+ dec ebx ; EBX = -1
int 0xAC
[global GetCPUNum]
-GetCPUNum:
- xor eax, eax
- str ax
- sub ax, 0x30
- shr ax, 3 ; ax /= 8
+GetCPUNum: ; TODO: Store in debug registers
+ mov eax, dr1
+ ret
+
+[extern GetEIP]
+[global GetEIP_Sched]
+[global GetEIP_Sched_ret]
+GetEIP_Sched_ret equ GetEIP_Sched.ret
+GetEIP_Sched:
+ call GetEIP
+GetEIP_Sched.ret:
ret
; Usermode code exported by the kernel
[section .usertext]
+; Export a place for the user to jump to to call a syscall
+; - Allows the kernel to change the method easily
+User_Syscall:
+ xchg bx, bx ; MAGIC BREAKPOINT
+ int 0xAC
+
+; A place to return to and exit
User_Syscall_RetAndExit:
push eax
call User_Syscall_Exit
xor eax, eax
mov ebx, [esp+4]
int 0xAC
+
+; vim: ft=nasm ts=8