mpx386.s

Minix比较全的源码

	push	(_irq_handlers+4*irq)	/* irq_handlers[irq]		  */;\
	call	_intr_handle		/* intr_handle(irq_handlers[irq]) */;\
	pop	ecx							    ;\
	cmp	(_irq_actids+4*irq), 0	/* interrupt still active?	  */;\
	jz	0f							    ;\
	inb	INT2_CTLMASK						    ;\
	orb	al, [1<<[irq-8]]					    ;\
	outb	INT2_CTLMASK		/* disable the irq		  */;\
0:	movb	al, END_OF_INT						    ;\
	outb	INT_CTL			/* reenable master 8259		  */;\
	outb	INT2_CTL		/* reenable slave 8259		  */;\
	ret				/* restart (another) process      */

! Each of these entry points is an expansion of the hwint_slave macro
	.align	16
_hwint08:		! Interrupt routine for irq 8 (realtime clock)
	hwint_slave(8)

	.align	16
_hwint09:		! Interrupt routine for irq 9 (irq 2 redirected)
	hwint_slave(9)

	.align	16
_hwint10:		! Interrupt routine for irq 10
	hwint_slave(10)

	.align	16
_hwint11:		! Interrupt routine for irq 11
	hwint_slave(11)

	.align	16
_hwint12:		! Interrupt routine for irq 12
	hwint_slave(12)

	.align	16
_hwint13:		! Interrupt routine for irq 13 (FPU exception)
	hwint_slave(13)

	.align	16
_hwint14:		! Interrupt routine for irq 14 (AT winchester)
	hwint_slave(14)

	.align	16
_hwint15:		! Interrupt routine for irq 15
	hwint_slave(15)

!*===========================================================================*
!*				save					     *
!*===========================================================================*
! Save for protected mode.
! This is much simpler than for 8086 mode, because the stack already points
! into the process table, or has already been switched to the kernel stack.

	.align	16
save:
	cld			! set direction flag to a known value
	pushad			! save "general" registers
    o16	push	ds		! save ds
    o16	push	es		! save es
    o16	push	fs		! save fs
    o16	push	gs		! save gs
	mov	dx, ss		! ss is kernel data segment
	mov	ds, dx		! load rest of kernel segments
	mov	es, dx		! kernel does not use fs, gs
	mov	eax, esp	! prepare to return
	incb	(_k_reenter)	! from -1 if not reentering
	jnz	set_restart1	! stack is already kernel stack
	mov	esp, k_stktop
	push	_restart	! build return address for int handler
	xor	ebp, ebp	! for stacktrace
	jmp	RETADR-P_STACKBASE(eax)

	.align	4
set_restart1:
	push	restart1
	jmp	RETADR-P_STACKBASE(eax)

!*===========================================================================*
!*				_s_call					     *
!*===========================================================================*
	.align	16
_s_call:
_p_s_call:
	cld			! set direction flag to a known value
	sub	esp, 6*4	! skip RETADR, eax, ecx, edx, ebx, est
	push	ebp		! stack already points into proc table
	push	esi
	push	edi
    o16	push	ds
    o16	push	es
    o16	push	fs
    o16	push	gs
	mov	si, ss		! ss is kernel data segment
	mov	ds, si		! load rest of kernel segments
	mov	es, si		! kernel does not use fs, gs
	incb	(_k_reenter)	! increment kernel entry count
	mov	esi, esp	! assumes P_STACKBASE == 0
	mov	esp, k_stktop
	xor	ebp, ebp	! for stacktrace
				! end of inline save
				! now set up parameters for sys_call()
	push	edx		! event set or flags bit map 
	push	ebx		! pointer to user message
	push	eax		! source / destination
	push	ecx		! call number (ipc primitive to use)
	call	_sys_call	! sys_call(call_nr, src_dst, m_ptr, bit_map)
				! caller is now explicitly in proc_ptr
	mov	AXREG(esi), eax	! sys_call MUST PRESERVE si

! Fall into code to restart proc/task running.

!*===========================================================================*
!*				restart					     *
!*===========================================================================*
_restart:

! Restart the current process or the next process if it is set. 

	cmp	(_next_ptr), 0		! see if another process is scheduled
	jz	0f
	mov 	eax, (_next_ptr)
	mov	(_proc_ptr), eax	! schedule new process 
	mov	(_next_ptr), 0
0:	mov	esp, (_proc_ptr)	! will assume P_STACKBASE == 0
	lldt	P_LDT_SEL(esp)		! enable process' segment descriptors 
	lea	eax, P_STACKTOP(esp)	! arrange for next interrupt
	mov	(_tss+TSS3_S_SP0), eax	! to save state in process table
restart1:
	decb	(_k_reenter)
    o16	pop	gs
    o16	pop	fs
    o16	pop	es
    o16	pop	ds
	popad
	add	esp, 4		! skip return adr
	iretd			! continue process

!*===========================================================================*
!*				exception handlers			     *
!*===========================================================================*
_divide_error:
	push	DIVIDE_VECTOR
	jmp	exception

_single_step_exception:
	push	DEBUG_VECTOR
	jmp	exception

_nmi:
	push	NMI_VECTOR
	jmp	exception

_breakpoint_exception:
	push	BREAKPOINT_VECTOR
	jmp	exception

_overflow:
	push	OVERFLOW_VECTOR
	jmp	exception

_bounds_check:
	push	BOUNDS_VECTOR
	jmp	exception

_inval_opcode:
	push	INVAL_OP_VECTOR
	jmp	exception

_copr_not_available:
	push	COPROC_NOT_VECTOR
	jmp	exception

_double_fault:
	push	DOUBLE_FAULT_VECTOR
	jmp	errexception

_copr_seg_overrun:
	push	COPROC_SEG_VECTOR
	jmp	exception

_inval_tss:
	push	INVAL_TSS_VECTOR
	jmp	errexception

_segment_not_present:
	push	SEG_NOT_VECTOR
	jmp	errexception

_stack_exception:
	push	STACK_FAULT_VECTOR
	jmp	errexception

_general_protection:
	push	PROTECTION_VECTOR
	jmp	errexception

_page_fault:
	push	PAGE_FAULT_VECTOR
	jmp	errexception

_copr_error:
	push	COPROC_ERR_VECTOR
	jmp	exception

!*===========================================================================*
!*				exception				     *
!*===========================================================================*
! This is called for all exceptions which do not push an error code.

	.align	16
exception:
 sseg	mov	(trap_errno), 0		! clear trap_errno
 sseg	pop	(ex_number)
	jmp	exception1

!*===========================================================================*
!*				errexception				     *
!*===========================================================================*
! This is called for all exceptions which push an error code.

	.align	16
errexception:
 sseg	pop	(ex_number)
 sseg	pop	(trap_errno)
exception1:				! Common for all exceptions.
	push	eax			! eax is scratch register
	mov	eax, 0+4(esp)		! old eip
 sseg	mov	(old_eip), eax
	movzx	eax, 4+4(esp)		! old cs
 sseg	mov	(old_cs), eax
	mov	eax, 8+4(esp)		! old eflags
 sseg	mov	(old_eflags), eax
	pop	eax
	call	save
	push	(old_eflags)
	push	(old_cs)
	push	(old_eip)
	push	(trap_errno)
	push	(ex_number)
	call	_exception		! (ex_number, trap_errno, old_eip,
					!	old_cs, old_eflags)
	add	esp, 5*4
	ret

!*===========================================================================*
!*				level0_call				     *
!*===========================================================================*
_level0_call:
	call	save
	jmp	(_level0_func)

!*===========================================================================*
!*				data					     *
!*===========================================================================*

.sect .rom	! Before the string table please
	.data2	0x526F		! this must be the first data entry (magic #)

.sect .bss
k_stack:
	.space	K_STACK_BYTES	! kernel stack
k_stktop:			! top of kernel stack
	.comm	ex_number, 4
	.comm	trap_errno, 4
	.comm	old_eip, 4
	.comm	old_cs, 4
	.comm	old_eflags, 4