label next_usage_update dword at 0xB008
label timer_ticks dword at 0xFDF0
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; IRQ0 HANDLER (TIMER INTERRUPT) ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
align 32
irq0:
cmp [error_interrupt],-1
je no_error_in_previous_process
mov edi,[error_interrupt]
shl edi, 3
mov [edi+tss0i_l +5], word 01010000b *256 +11101001b
mov edi,[error_interrupt]
shl edi,7
add edi,0x290000
mov esi,[error_interrupt_entry]
mov [edi+l.eip-tss_sceleton],esi
mov [edi+l.eflags-tss_sceleton],dword 0x11002
mov [0xffff],byte 0
mov [error_interrupt],-1
no_error_in_previous_process:
mov edi,[0x3000]
shl edi, 3
; fields of TSS descriptor:
mov [edi+gdts+ tss0 +5], word 01010000b *256 +11101001b
inc dword [timer_ticks]
mov eax, [timer_ticks]
;!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
call playNote ; <<<--- INSERT THIS LINE !!!!!!!!!!
;!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
cmp eax,[next_usage_update]
jb .nocounter
add eax,100
mov [next_usage_update],eax
call updatecputimes
.nocounter:
mov edi, [0x3010]
mov ebx, [edi+0x18] ; time stamp counter add
call _rdtsc
sub eax, ebx
add eax, [edi+0x14] ; counter sum
mov [edi+0x14], eax
mov ebx,[0x3000]
cmp [0xffff], byte 1 ;1
je do_not_change_task ;je
.waiting_for_termination:
.waiting_for_reuse:
.waiting_on_queue:
add edi,0x20
inc ebx
mov al, byte [edi+0xA]
cmp al, 3
je .waiting_for_termination
cmp al, 4
je .waiting_for_termination
cmp al, 9
je .waiting_for_reuse
cmp al, 16
je .waiting_on_queue
cmp al, 17
je .waiting_on_queue
cmp ebx,[0x3004]
jbe nsched0
mov ebx,1
mov edi,0x3020
nsched0:
mov [0x3000],ebx
mov [0x3010],edi
do_not_change_task:
mov edx,[0x3000]
lea edx,[tss0sys+8*edx]
;mov [8*0x40+idts+8+0], word 0
;mov [8*0x40+idts+8+2],dx
;mov [8*0x40+idts+8+4],word 11100101b*256
;mov [8*0x40+idts+8+6], word 0
call _rdtsc
mov [edi+0x18],eax
cmp [0xffff],byte 0
je nodecffff
dec byte [0xffff]
nodecffff:
shl ebx, 3
xor eax, eax
add ebx, tss0
mov word [0xB004], bx ; selector ;mov [tss_s],bx
mov dword [0xB000], eax ; offset
mov al,0x20 ; send End Of Interrupt signal
mov dx,0x20
out dx,al
.switch:
jmp pword [0xB000]
inc [context_counter] ;noname & halyavin
jmp irq0
iglobal
context_counter dd 0 ;noname & halyavin
endg
align 4
change_task:
mov [0xffff],byte 2
dec dword [timer_ticks] ; because irq0 will increase it
int 0x20 ; irq0 handler
ret
align 4
updatecputimes:
mov eax,[idleuse]
mov [idleusesec],eax
mov [idleuse],dword 0
mov ecx, [0x3004]
mov edi, 0x3020
.newupdate:
mov ebx,[edi+0x14]
mov [edi+0x1c],ebx
mov [edi+0x14],dword 0
add edi,0x20
dec ecx
jnz .newupdate
ret
;
; Wait queue is 16 bytes
; dd return code +12
; dd pointer to process +8
; dd prev +4
; dd next +0
;
; eax - pointer to pointer to the wait queue
; return:
; ecx - return code
sleep_on_queue:
sub esp,16 ; reserve space for wait node
mov ecx,esp ; ecx=this_node, [eax]=queue
pusha
mov ebx,[0x3010] ; get pointer to the current process
mov [ecx+8],ebx
pushf
cli ; adding element to the wait queue must be atomic
mov edi,[eax] ; edi=queue
and edi,edi ; check if queue is empty
jz .is_empty
; add element at the end of wait queue
mov edx,[edi+4] ; get pointer to prev edx=queue->prev
mov [ecx+4],edx ; this_node->prev=queue->prev
mov [ecx+0],edi ; this_node->next=queue
mov [edx+0],ecx ; this_node->prev->next=this_node
mov [edi+4],ecx ; queue->prev=this_node
jmp .added_ok
.is_empty:
; set this element as first in the queue
mov [ecx+0],ecx ; this_node->next=this_node
mov [ecx+4],ecx ; this_node->prev=this_node
mov [eax],ecx ; [queue]=this_node
.added_ok:
popf ; we can safely restore interrupts
mov [ebx+0xa],byte 17 ; set current task state as sleeping
call change_task ; schedule new thread
; someone has called wake_up_queue
pushf ; disable interrupts
cli
mov edx,[ecx+0] ; edx=this_node->next
mov esi,[ecx+4] ; esi=this_node->prev
; check if we need to remove this node from head
cmp [eax],ecx
jne .no_head
cmp [ecx+0],ecx ; check if queue is empty
jne .not_empty
mov [eax],dword 0
jmp .no_head
.not_empty:
mov [eax],edx
; remove our node from the queue (this must be atomic)
.no_head:
mov [edx+4],esi ; this_node->next->prev=this_node->prev
mov [esi+0],edx ; this_node->prev->next=this_node->next
popf
popa
add esp,12
pop ecx
ret
; eax - pointer to the wait queue
; ebx - wake up all (1=yes, 0=no)
; ecx - return code
; return:
; ebx - number of processes woken
wake_up_queue:
and eax,eax
jnz .nz
ret
.nz:
push eax
push ebx
push ecx
push edx
push esi
pushf
cli
xor ebx,ebx
mov edx,eax
.wake_loop:
mov [edx+12],ecx
mov esi,[edx+8]
mov byte [esi+0xa],0
inc ebx
mov edx,[edx+0]
cmp edx,eax
jne .wake_loop
and ebx,ebx
jz .wake_up_1
.return_it:
popf
pop esi
pop edx
pop ecx
add esp,4
pop eax
ret
.wake_up_1:
mov [eax+12],ecx
mov ecx,[eax+8]
mov byte [ecx+0xa],0
jmp .return_it