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;; IRQ0 HANDLER (TIMER INTERRUPT) ;;
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align 32
irq0:
pushfd
pushad
mov ax, app_data ;
mov ds, ax
mov es, ax
inc dword [timer_ticks]
mov eax, [timer_ticks]
call playNote ; <<<--- Speaker driver
cmp eax,[next_usage_update]
jb .nocounter
add eax,100
mov [next_usage_update],eax
call updatecputimes
.nocounter:
cmp [DONT_SWITCH], byte 1
jne .change_task
mov al,0x20 ; send End Of Interrupt signal
mov dx,0x20
out dx,al
mov [DONT_SWITCH], byte 0
popad
popfd
iretd
.change_task:
call update_counters
call find_next_task
mov ecx, eax
mov al,0x20 ; send End Of Interrupt signal
mov dx,0x20
out dx,al
test ecx, ecx ; if there is only one running process
jnz .return
call do_change_task
.return:
popad
popfd
iretd
align 4
change_task:
pushfd
cli
pushad
call update_counters
if 0
; \begin{Mario79}
cmp [dma_task_switched], 1
jne .find_next_task
mov [dma_task_switched], 0
mov ebx, [dma_process]
cmp [CURRENT_TASK], ebx
je .return
mov edi, [dma_slot_ptr]
mov [CURRENT_TASK], ebx
mov [TASK_BASE], edi
jmp @f
.find_next_task:
; \end{Mario79}
end if
call find_next_task
test eax, eax ; the same task -> skip switch
jnz .return
@@:
mov [DONT_SWITCH],byte 1
call do_change_task
.return:
popad
popfd
ret
uglobal
align 4
far_jump:
.offs dd ?
.sel dw ?
context_counter dd ? ;noname & halyavin
next_usage_update dd ?
timer_ticks dd ?
prev_slot dd ?
event_sched dd ?
endg
update_counters:
mov edi, [TASK_BASE]
mov ebx, [edi+TASKDATA.counter_add] ; time stamp counter add
rdtsc
sub eax, ebx
add eax, [edi+TASKDATA.counter_sum] ; counter sum
mov [edi+TASKDATA.counter_sum], eax
ret
; Find next task to execute
; result: ebx = number of the selected task
; eax = 1 if the task is the same
; edi = address of the data for the task in ebx
; [0x3000] = ebx and [0x3010] = edi
; corrupts other regs
find_next_task:
mov ebx, [CURRENT_TASK]
mov edi, [TASK_BASE]
mov [prev_slot], ebx
.waiting_for_termination:
.waiting_for_reuse:
.waiting_for_event:
.suspended:
cmp ebx, [TASK_COUNT]
jb @f
mov edi, CURRENT_TASK
xor ebx, ebx
@@:
add edi,0x20
inc ebx
mov al, byte [edi+TASKDATA.state]
test al, al
jz .found
cmp al, 1
jz .suspended
cmp al, 2
jz .suspended
cmp al, 3
je .waiting_for_termination
cmp al, 4
je .waiting_for_termination
cmp al, 9
je .waiting_for_reuse
mov [CURRENT_TASK],ebx
mov [TASK_BASE],edi
cmp al, 5
jne .noevents
call get_event_for_app
test eax, eax
jz .waiting_for_event
mov [event_sched], eax
mov [edi+TASKDATA.state], byte 0
.noevents:
.found:
mov [CURRENT_TASK],ebx
mov [TASK_BASE],edi
rdtsc ;call _rdtsc
mov [edi+TASKDATA.counter_add],eax
mov esi, [prev_slot]
xor eax, eax
cmp ebx, esi
sete al
ret
; in: ebx = TSS selector index
;
; param
; ebx = incoming task
; esi = outcomig task
do_change_task:
shl ebx, 8
add ebx, SLOT_BASE
mov [current_slot], ebx
shl esi, 8
add esi, SLOT_BASE
mov [esi+APPDATA.saved_esp], esp
mov esp, [ebx+APPDATA.saved_esp]
mov eax, [ebx+APPDATA.dir_table]
mov cr3, eax
mov ebx, [ebx+APPDATA.pl0_stack]
add ebx, RING0_STACK_SIZE
mov [tss_data+TSS._esp0], ebx
mov ecx, cr0
or ecx, CR0_TS ;set task switch flag
mov cr0, ecx
inc [context_counter] ;noname & halyavin
ret
;
; shl ebx, 3
; xor eax, eax
; add ebx, tss0
; mov [far_jump.sel], bx ; selector
; mov [far_jump.offs], eax ; offset
; jmp pword [far_jump]
; inc [context_counter] ;noname & halyavin
;ret
align 4
updatecputimes:
mov eax,[idleuse]
mov [idleusesec],eax
mov [idleuse],dword 0
mov ecx, [TASK_COUNT]
mov edi, TASK_DATA
.newupdate:
mov ebx,[edi+TASKDATA.counter_sum]
mov [edi+TASKDATA.cpu_usage],ebx
mov [edi+TASKDATA.counter_sum],dword 0
add edi,0x20
dec ecx
jnz .newupdate
ret