;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; IRQ0 HANDLER (TIMER INTERRUPT) ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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
; 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]
; set thread io map
mov ecx, [ebx+APPDATA.io_map]
mov edx, [ebx+APPDATA.io_map+4]
mov dword [page_tabs+((tss._io_map_0 and -4096) shr 10)], ecx
mov dword [page_tabs+((tss._io_map_1 and -4096) shr 10)], edx
mov eax, [ebx+APPDATA.dir_table]
mov cr3, eax
mov ebx, [ebx+APPDATA.pl0_stack]
add ebx, RING0_STACK_SIZE
mov [tss._esp0], ebx
mov ecx, cr0
or ecx, CR0_TS ;set task switch flag
mov cr0, ecx
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
if 0
struc TIMER
{
.next dd ?
.exp_time dd ?
.func dd ?
.arg dd ?
}
MAX_PROIRITY 0 ; highest, used for kernel tasks
MAX_USER_PRIORITY 0 ; highest priority for user processes
USER_PRIORITY 7 ; default (should correspond to nice 0)
MIN_USER_PRIORITY 14 ; minimum priority for user processes
IDLE_PRIORITY 15 ; lowest, only IDLE process goes here
NR_SCHED_QUEUES 16 ; MUST equal IDLE_PRIORYTY + 1
rdy_head rd 16
align 4
pick_task:
xor eax, eax
.pick:
mov ebx, [rdy_head+eax*4]
test ebx, ebx
jz .next
mov [next_task], ebx
test [ebx+flags.billable]
jz @F
mov [bill_task], ebx
@@:
ret
.next:
inc eax
jmp .pick
; param
; eax= task
;
; retval
; eax= task
; ebx= queue
; ecx= front if 1 or back if 0
align 4
shed:
cmp [eax+.tics_left], 0 ;signed compare
mov ebx, [eax+.priority]
setg ecx
jg @F
mov edx, [eax+.tics_quantum]
mov [eax+.ticks_left], edx
cmp ebx, (IDLE_PRIORITY-1)
je @F
inc ebx
@@:
ret
; param
; eax= task
align 4
enqueue:
call shed ;eax
cmp [rdy_head+ebx*4],0
jnz @F
mov [rdy_head+ebx*4], eax
mov [rdy_tail+ebx*4], eax
mov [eax+.next_ready], 0
jmp .pick
@@:
test ecx, ecx
jz .back
mov ecx, [rdy_head+ebx*4]
mov [eax+.next_ready], ecx
mov [rdy_head+ebx*4], eax
jmp .pick
.back:
mov ecx, [rdy_tail+ebx*4]
mov [ecx+.next_ready], eax
mov [rdy_tail+ebx*4], eax
mov [eax+.next_ready], 0
.pick:
call pick_proc ;select next task
ret
end if