source: mainline/arch/ia32/src/asm.s@ b0bf501

#
# Copyright (C) 2001-2004 Jakub Jermar
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# - Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
# - Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
# - The name of the author may not be used to endorse or promote products
#   derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

## very low and hardware-level functions

.text

.global cpu_priority_high
.global cpu_priority_low
.global cpu_priority_restore
.global cpu_priority_read
.global cpu_halt
.global cpu_sleep
.global paging_on
.global cpu_read_dba
.global cpu_write_dba
.global cpu_read_cr2
.global enable_l_apic_in_msr
.global interrupt_handlers
.global inb
.global inw
.global inl
.global outb
.global outw
.global outl
.global memcopy
.global memsetb
.global memsetw
.global memcmp


## Set priority level high
#
# Disable interrupts and return previous
# EFLAGS in EAX.
#
cpu_priority_high:
        pushf
        pop %eax
        cli
        ret


## Set priority level low
#
# Enable interrupts and return previous
# EFLAGS in EAX.
#    
cpu_priority_low:
        pushf
        pop %eax
        sti
        ret


## Restore priority level
#
# Restore EFLAGS.
#
cpu_priority_restore:
        push 4(%esp)
        popf
        ret

## Return raw priority level
#
# Return EFLAFS in EAX.
#
cpu_priority_read:
        pushf
        pop %eax
        ret


## Halt the CPU
#
# Halt the CPU using HLT.
#
cpu_halt:
cpu_sleep:
        hlt
        ret


## Turn paging on
#
# Enable paging and write-back caching in CR0.
#
paging_on:
        pushl %eax
        movl %cr0,%eax
        orl $(1<<31),%eax               # paging on
        andl $~((1<<30)|(1<<29)),%eax   # clear Cache Disable and not Write Though
        movl %eax,%cr0
        jmp 0f
0:
        popl %eax
        ret


## Read CR3
#
# Store CR3 in EAX.
#
cpu_read_dba:
        movl %cr3,%eax
        ret


## Write CR3
#
# Set CR3.
#
cpu_write_dba:
        pushl %eax
        movl 8(%esp),%eax
        movl %eax,%cr3
        popl %eax
        ret


## Read CR2
#
# Store CR2 in EAX.
#
cpu_read_cr2:
        movl %cr2,%eax
        ret


## Enable local APIC
#
# Enable local APIC in MSR.
#
enable_l_apic_in_msr:
        pusha
        
        movl $0x1b, %ecx
        rdmsr
        orl $(1<<11),%eax
        orl $(0xfee00000),%eax
        wrmsr
        
        popa
        ret


## Declare interrupt handlers
#
# Declare interrupt handlers for n interrupt
# vectors starting at vector i.
#
# The handlers setup data segment registers
# and call trap_dispatcher().
#
.macro handler i n
        push %ebp
        movl %esp,%ebp
        pusha

        push %ds
        push %es
    
        # we must fill the data segment registers
        movw $16,%ax
        movw %ax,%ds
        movw %ax,%es
    
        movl $(\i),%edi
        pushl %ebp
        addl $4,(%esp)
        pushl %edi
        call trap_dispatcher
        addl $8,%esp

        pop %es
        pop %ds

        popa
        pop %ebp
    
        iret
    
        .if (\n-\i)-1
        handler "(\i+1)",\n
        .endif
.endm

# keep in sync with pm.h !!!
IDT_ITEMS=64
interrupt_handlers:
h_start:
        handler 0 64
#       handler 64 128  
#       handler 128 192
#       handler 192 256
h_end:


## I/O input (byte)
#
# Get a byte from I/O port and store it AL.
#
inb:
        push %edx
        xorl %eax,%eax
        movl 8(%esp),%edx
        inb %dx,%al
        pop %edx
        ret


## I/O input (word)
#
# Get a word from I/O port and store it AX.
#
inw:
        push %edx
        xorl %eax,%eax
        movl 8(%esp),%edx
        inw %dx,%ax
        pop %edx
        ret


## I/O input (dword)
#
# Get a dword from I/O port and store it EAX.
#
inl:
        push %edx
        xorl %eax,%eax
        movl 8(%esp),%edx
        inl %dx,%eax
        pop %edx
        ret


## I/O output (byte)
#
# Send a byte to I/O port.
#
outb:
        push %ebp
        movl %esp,%ebp
        pusha
    
        movl 8(%ebp),%edx
        movl 12(%ebp),%eax
        outb %al,%dx
    
        popa
        pop %ebp
        ret


## I/O output (word)
#
# Send a word to I/O port.
#
outw:
        push %ebp
        movl %esp,%ebp
        pusha
    
        movl 8(%ebp),%edx
        movl 12(%ebp),%eax
        outw %ax,%dx
    
        popa
        pop %ebp
        ret


## I/O output (dword)
#
# Send a dword to I/O port.
#
outl:
        push %ebp
        movl %esp,%ebp
        pusha
    
        movl 8(%ebp),%edx
        movl 12(%ebp),%eax
        outl %eax,%dx
    
        popa
        pop %ebp
        ret


## Copy memory
#
# Copy a given number of bytes (3rd argument)
# from the memory location defined by 1st argument
# to the memory location defined by 2nd argument.
# The memory areas cannot overlap.
#
SRC=8
DST=12
CNT=16
memcopy:
        push %ebp
        movl %esp,%ebp
        pusha
    
        cld
        movl CNT(%ebp),%ecx
        movl DST(%ebp),%edi
        movl SRC(%ebp),%esi    
    
        rep movsb %ds:(%esi),%es:(%edi)
    
        popa
        pop %ebp
        ret


## Fill memory with bytes
#
# Fill a given number of bytes (2nd argument)
# at memory defined by 1st argument with the
# byte value defined by 3rd argument.
#
DST=8
CNT=12
X=16
memsetb:
        push %ebp
        movl %esp,%ebp
        pusha
    
        cld
        movl CNT(%ebp),%ecx
        movl DST(%ebp),%edi
        movl X(%ebp),%eax
    
        rep stosb %al,%es:(%edi)
    
        popa
        pop %ebp
        ret


## Fill memory with words
#
# Fill a given number of words (2nd argument)
# at memory defined by 1st argument with the
# word value defined by 3rd argument.
#
DST=8
CNT=12
X=16
memsetw:
        push %ebp
        movl %esp,%ebp
        pusha
    
        cld
        movl CNT(%ebp),%ecx
        movl DST(%ebp),%edi
        movl X(%ebp),%eax
    
        rep stosw %ax,%es:(%edi)
    
        popa
        pop %ebp
        ret


## Compare memory regions for equality
#
# Compare a given number of bytes (3rd argument)
# at memory locations defined by 1st and 2nd argument
# for equality. If the bytes are equal, EAX contains
# 0.
#
SRC=12
DST=16
CNT=20
memcmp:
        push %ebp
        subl $4,%esp    
        movl %esp,%ebp

        pusha
    
        cld
        movl CNT(%ebp),%ecx
        movl DST(%ebp),%edi
        movl SRC(%ebp),%esi    
    
        repe cmpsb %es:(%edi),%ds:(%esi)
        movl %ecx,(%ebp)

        popa
        
        movl (%ebp),%eax        # return value => %eax (zero on success)
        addl $4,%esp
        pop %ebp
        
        ret


# THIS IS USERSPACE CODE
.global utext
utext:
0:
#       movl $0xdeadbeaf, %eax
        int $48
        jmp 0b
        # not reached
utext_end:

.data
.global utext_size
utext_size:
        .long utext_end - utext 


#.section K_DATA_START
.global interrupt_handler_size

interrupt_handler_size: .long (h_end-h_start)/IDT_ITEMS