ccd17ecfed
and type) are overwritten with newer flags/ arguments. The interface from within the kernel is lock_notify(). User processes can make a system call with notify(). NOTIFY fully replaces the old notification mechanism.
558 lines
16 KiB
ArmAsm
Executable file
558 lines
16 KiB
ArmAsm
Executable file
#
|
|
! This file, mpx386.s, is included by mpx.s when Minix is compiled for
|
|
! 32-bit Intel CPUs. The alternative mpx88.s is compiled for 16-bit CPUs.
|
|
|
|
! This file is part of the lowest layer of the MINIX kernel. (The other part
|
|
! is "proc.c".) The lowest layer does process switching and message handling.
|
|
! Furthermore it contains the assembler startup code for Minix and the 32-bit
|
|
! interrupt handlers. It cooperates with the code in "start.c" to set up a
|
|
! good environment for main().
|
|
|
|
! Every transition to the kernel goes through this file. Transitions to the
|
|
! kernel may be nested. The initial entry may be with a system call (i.e.,
|
|
! send or receive a message), an exception or a hardware interrupt; kernel
|
|
! reentries may only be made by hardware interrupts. The count of reentries
|
|
! is kept in "k_reenter". It is important for deciding whether to switch to
|
|
! the kernel stack and for protecting the message passing code in "proc.c".
|
|
|
|
! For the message passing trap, most of the machine state is saved in the
|
|
! proc table. (Some of the registers need not be saved.) Then the stack is
|
|
! switched to "k_stack", and interrupts are reenabled. Finally, the system
|
|
! call handler (in C) is called. When it returns, interrupts are disabled
|
|
! again and the code falls into the restart routine, to finish off held-up
|
|
! interrupts and run the process or task whose pointer is in "proc_ptr".
|
|
|
|
! Hardware interrupt handlers do the same, except (1) The entire state must
|
|
! be saved. (2) There are too many handlers to do this inline, so the save
|
|
! routine is called. A few cycles are saved by pushing the address of the
|
|
! appropiate restart routine for a return later. (3) A stack switch is
|
|
! avoided when the stack is already switched. (4) The (master) 8259 interrupt
|
|
! controller is reenabled centrally in save(). (5) Each interrupt handler
|
|
! masks its interrupt line using the 8259 before enabling (other unmasked)
|
|
! interrupts, and unmasks it after servicing the interrupt. This limits the
|
|
! nest level to the number of lines and protects the handler from itself.
|
|
|
|
! For communication with the boot monitor at startup time some constant
|
|
! data are compiled into the beginning of the text segment. This facilitates
|
|
! reading the data at the start of the boot process, since only the first
|
|
! sector of the file needs to be read.
|
|
|
|
! Some data storage is also allocated at the end of this file. This data
|
|
! will be at the start of the data segment of the kernel and will be read
|
|
! and modified by the boot monitor before the kernel starts.
|
|
|
|
! sections
|
|
|
|
.sect .text
|
|
begtext:
|
|
.sect .rom
|
|
begrom:
|
|
.sect .data
|
|
begdata:
|
|
.sect .bss
|
|
begbss:
|
|
|
|
#include <minix/config.h>
|
|
#include <minix/const.h>
|
|
#include <minix/com.h>
|
|
#include <ibm/interrupt.h>
|
|
#include "const.h"
|
|
#include "protect.h"
|
|
#include "sconst.h"
|
|
|
|
/* Selected 386 tss offsets. */
|
|
#define TSS3_S_SP0 4
|
|
|
|
! Exported functions
|
|
! Note: in assembly language the .define statement applied to a function name
|
|
! is loosely equivalent to a prototype in C code -- it makes it possible to
|
|
! link to an entity declared in the assembly code but does not create
|
|
! the entity.
|
|
|
|
.define _restart
|
|
.define save
|
|
|
|
.define _divide_error
|
|
.define _single_step_exception
|
|
.define _nmi
|
|
.define _breakpoint_exception
|
|
.define _overflow
|
|
.define _bounds_check
|
|
.define _inval_opcode
|
|
.define _copr_not_available
|
|
.define _double_fault
|
|
.define _copr_seg_overrun
|
|
.define _inval_tss
|
|
.define _segment_not_present
|
|
.define _stack_exception
|
|
.define _general_protection
|
|
.define _page_fault
|
|
.define _copr_error
|
|
|
|
.define _hwint00 ! handlers for hardware interrupts
|
|
.define _hwint01
|
|
.define _hwint02
|
|
.define _hwint03
|
|
.define _hwint04
|
|
.define _hwint05
|
|
.define _hwint06
|
|
.define _hwint07
|
|
.define _hwint08
|
|
.define _hwint09
|
|
.define _hwint10
|
|
.define _hwint11
|
|
.define _hwint12
|
|
.define _hwint13
|
|
.define _hwint14
|
|
.define _hwint15
|
|
|
|
.define _s_call
|
|
.define _p_s_call
|
|
.define _level0_call
|
|
|
|
! Exported variables.
|
|
.define begbss
|
|
.define begdata
|
|
|
|
.sect .text
|
|
!*===========================================================================*
|
|
!* MINIX *
|
|
!*===========================================================================*
|
|
MINIX: ! this is the entry point for the MINIX kernel
|
|
jmp over_flags ! skip over the next few bytes
|
|
.data2 CLICK_SHIFT ! for the monitor: memory granularity
|
|
flags:
|
|
.data2 0x01FD ! boot monitor flags:
|
|
! call in 386 mode, make bss, make stack,
|
|
! load high, don`t patch, will return,
|
|
! uses generic INT, memory vector,
|
|
! new boot code return
|
|
nop ! extra byte to sync up disassembler
|
|
over_flags:
|
|
|
|
! Set up a C stack frame on the monitor stack. (The monitor sets cs and ds
|
|
! right. The ss descriptor still references the monitor data segment.)
|
|
movzx esp, sp ! monitor stack is a 16 bit stack
|
|
push ebp
|
|
mov ebp, esp
|
|
push esi
|
|
push edi
|
|
cmp 4(ebp), 0 ! monitor return vector is
|
|
jz noret ! nonzero if return possible
|
|
inc (_mon_return)
|
|
noret: mov (_mon_sp), esp ! save stack pointer for later return
|
|
|
|
! Copy the monitor global descriptor table to the address space of kernel and
|
|
! switch over to it. Prot_init() can then update it with immediate effect.
|
|
|
|
sgdt (_gdt+GDT_SELECTOR) ! get the monitor gdtr
|
|
mov esi, (_gdt+GDT_SELECTOR+2) ! absolute address of GDT
|
|
mov ebx, _gdt ! address of kernel GDT
|
|
mov ecx, 8*8 ! copying eight descriptors
|
|
copygdt:
|
|
eseg movb al, (esi)
|
|
movb (ebx), al
|
|
inc esi
|
|
inc ebx
|
|
loop copygdt
|
|
mov eax, (_gdt+DS_SELECTOR+2) ! base of kernel data
|
|
and eax, 0x00FFFFFF ! only 24 bits
|
|
add eax, _gdt ! eax = vir2phys(gdt)
|
|
mov (_gdt+GDT_SELECTOR+2), eax ! set base of GDT
|
|
lgdt (_gdt+GDT_SELECTOR) ! switch over to kernel GDT
|
|
|
|
! Locate boot parameters, set up kernel segment registers and stack.
|
|
mov ebx, 8(ebp) ! boot parameters offset
|
|
mov edx, 12(ebp) ! boot parameters length
|
|
mov eax, 16(ebp) ! address of a.out headers
|
|
mov (_aout), eax
|
|
mov ax, ds ! kernel data
|
|
mov es, ax
|
|
mov fs, ax
|
|
mov gs, ax
|
|
mov ss, ax
|
|
mov esp, k_stktop ! set sp to point to the top of kernel stack
|
|
|
|
! Call C startup code to set up a proper environment to run main().
|
|
push edx
|
|
push ebx
|
|
push SS_SELECTOR
|
|
push DS_SELECTOR
|
|
push CS_SELECTOR
|
|
call _cstart ! cstart(cs, ds, mds, parmoff, parmlen)
|
|
add esp, 5*4
|
|
|
|
! Reload gdtr, idtr and the segment registers to global descriptor table set
|
|
! up by prot_init().
|
|
|
|
lgdt (_gdt+GDT_SELECTOR)
|
|
lidt (_gdt+IDT_SELECTOR)
|
|
|
|
jmpf CS_SELECTOR:csinit
|
|
csinit:
|
|
o16 mov ax, DS_SELECTOR
|
|
mov ds, ax
|
|
mov es, ax
|
|
mov fs, ax
|
|
mov gs, ax
|
|
mov ss, ax
|
|
o16 mov ax, TSS_SELECTOR ! no other TSS is used
|
|
ltr ax
|
|
push 0 ! set flags to known good state
|
|
popf ! esp, clear nested task and int enable
|
|
|
|
jmp _main ! main()
|
|
|
|
|
|
!*===========================================================================*
|
|
!* interrupt handlers *
|
|
!* interrupt handlers for 386 32-bit protected mode *
|
|
!*===========================================================================*
|
|
|
|
!*===========================================================================*
|
|
!* hwint00 - 07 *
|
|
!*===========================================================================*
|
|
! Note this is a macro, it just looks like a subroutine.
|
|
#define hwint_master_slave_fail(irq) \
|
|
call save /* save interrupted process state */;\
|
|
cli ;\
|
|
inb INT2_CTLMASK /* get current mask */ ;\
|
|
movb ah, al ;\
|
|
inb INT_CTLMASK /* get current mask */ ;\
|
|
push eax ;\
|
|
cli ;\
|
|
movb al, ~[0] ;\
|
|
outb INT_CTLMASK /* mask all */;\
|
|
outb INT2_CTLMASK /* */;\
|
|
cli ;\
|
|
push (_irq_handlers+4*irq) /* irq_handlers[irq] */;\
|
|
call _intr_handle /* intr_handle(irq_handlers[irq]) */;\
|
|
pop ecx ;\
|
|
pop eax ;\
|
|
cmp (_irq_actids+4*irq), 0 /* interrupt still active? */;\
|
|
jz 0f ;\
|
|
or eax, [1<<irq] /* mask irq */ ;\
|
|
0: outb INT_CTLMASK /* restore master irq mask */;\
|
|
movb al, ah ;\
|
|
outb INT2_CTLMASK /* restore slave irq mask */;\
|
|
movb al, END_OF_INT ;\
|
|
outb INT_CTL /* reenable master 8259 */;\
|
|
cmp (irq), 8 ;\
|
|
jb 1f ;\
|
|
outb INT2_CTL /* reenable slave 8259 */;\
|
|
1: ret /* restart (another) process */
|
|
|
|
#define hwint_master(irq) \
|
|
call save /* save interrupted process state */;\
|
|
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 INT_CTLMASK /* get current mask */ ;\
|
|
orb al, [1<<irq] /* mask irq */ ;\
|
|
outb INT_CTLMASK /* disable the irq */;\
|
|
0: movb al, END_OF_INT ;\
|
|
outb INT_CTL /* reenable master 8259 */;\
|
|
ret /* restart (another) process */
|
|
|
|
! Each of these entry points is an expansion of the hwint_master macro
|
|
.align 16
|
|
_hwint00: ! Interrupt routine for irq 0 (the clock).
|
|
hwint_master(0)
|
|
|
|
.align 16
|
|
_hwint01: ! Interrupt routine for irq 1 (keyboard)
|
|
hwint_master(1)
|
|
|
|
.align 16
|
|
_hwint02: ! Interrupt routine for irq 2 (cascade!)
|
|
hwint_master(2)
|
|
|
|
.align 16
|
|
_hwint03: ! Interrupt routine for irq 3 (second serial)
|
|
hwint_master(3)
|
|
|
|
.align 16
|
|
_hwint04: ! Interrupt routine for irq 4 (first serial)
|
|
hwint_master(4)
|
|
|
|
.align 16
|
|
_hwint05: ! Interrupt routine for irq 5 (XT winchester)
|
|
hwint_master(5)
|
|
|
|
.align 16
|
|
_hwint06: ! Interrupt routine for irq 6 (floppy)
|
|
hwint_master(6)
|
|
|
|
.align 16
|
|
_hwint07: ! Interrupt routine for irq 7 (printer)
|
|
hwint_master(7)
|
|
|
|
!*===========================================================================*
|
|
!* hwint08 - 15 *
|
|
!*===========================================================================*
|
|
! Note this is a macro, it just looks like a subroutine.
|
|
#define hwint_slave(irq) \
|
|
call save /* save interrupted process state */;\
|
|
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 dx, ss
|
|
mov ds, dx
|
|
mov es, dx
|
|
incb (_k_reenter)
|
|
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 ebx ! pointer to user message
|
|
push eax ! src/dest
|
|
push ecx ! SEND/RECEIVE/BOTH
|
|
call _sys_call ! sys_call(function, src_dest, m_ptr)
|
|
! 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.
|
|
|
|
mov esp, (_proc_ptr) ! will assume P_STACKBASE == 0
|
|
lldt P_LDT_SEL(esp) ! enable segment descriptors for task
|
|
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
|