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#
# Copyright (C) 2003-2004 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.
#
#include <arch/asm/regname.h>
#include <arch/mm/page.h>
#include <arch/asm/boot.h>
#include <arch/context_offset.h>
.text
.set noat
.set noreorder
.set nomacro
.global kernel_image_start
.global tlb_refill_entry
.global cache_error_entry
.global exception_entry
.global userspace_asm
# Save registers to space defined by \r
# We will change $at on the way
.macro REGISTERS_STORE r
sw $at,EOFFSET_AT(\r)
sw $v0,EOFFSET_V0(\r)
sw $v1,EOFFSET_V1(\r)
sw $a0,EOFFSET_A0(\r)
sw $a1,EOFFSET_A1(\r)
sw $a2,EOFFSET_A2(\r)
sw $a3,EOFFSET_A3(\r)
sw $t0,EOFFSET_T0(\r)
sw $t1,EOFFSET_T1(\r)
sw $t2,EOFFSET_T2(\r)
sw $t3,EOFFSET_T3(\r)
sw $t4,EOFFSET_T4(\r)
sw $t5,EOFFSET_T5(\r)
sw $t6,EOFFSET_T6(\r)
sw $t7,EOFFSET_T7(\r)
sw $t8,EOFFSET_T8(\r)
sw $t9,EOFFSET_T9(\r)
mflo $at
sw $at, EOFFSET_LO(\r)
mfhi $at
sw $at, EOFFSET_HI(\r)
sw $s0,EOFFSET_S0(\r)
sw $s1,EOFFSET_S1(\r)
sw $s2,EOFFSET_S2(\r)
sw $s3,EOFFSET_S3(\r)
sw $s4,EOFFSET_S4(\r)
sw $s5,EOFFSET_S5(\r)
sw $s6,EOFFSET_S6(\r)
sw $s7,EOFFSET_S7(\r)
sw $s8,EOFFSET_S8(\r)
sw $gp,EOFFSET_GP(\r)
sw $ra,EOFFSET_RA(\r)
sw $sp,EOFFSET_SP(\r)
mfc0 $at, $status
sw $at,EOFFSET_STATUS(\r)
mfc0 $at, $epc
sw $at,EOFFSET_EPC(\r)
.endm
.macro REGISTERS_LOAD r
lw $v0,EOFFSET_V0(\r)
lw $v1,EOFFSET_V1(\r)
lw $a0,EOFFSET_A0(\r)
lw $a1,EOFFSET_A1(\r)
lw $a2,EOFFSET_A2(\r)
lw $a3,EOFFSET_A3(\r)
lw $t0,EOFFSET_T0(\r)
lw $t1,EOFFSET_T1(\r)
lw $t2,EOFFSET_T2(\r)
lw $t3,EOFFSET_T3(\r)
lw $t4,EOFFSET_T4(\r)
lw $t5,EOFFSET_T5(\r)
lw $t6,EOFFSET_T6(\r)
lw $t7,EOFFSET_T7(\r)
lw $t8,EOFFSET_T8(\r)
lw $t9,EOFFSET_T9(\r)
lw $s0,EOFFSET_S0(\r)
lw $s1,EOFFSET_S1(\r)
lw $s2,EOFFSET_S2(\r)
lw $s3,EOFFSET_S3(\r)
lw $s4,EOFFSET_S4(\r)
lw $s5,EOFFSET_S5(\r)
lw $s6,EOFFSET_S6(\r)
lw $s7,EOFFSET_S7(\r)
lw $s8,EOFFSET_S8(\r)
lw $gp,EOFFSET_GP(\r)
lw $ra,EOFFSET_RA(\r)
lw $at,EOFFSET_LO(\r)
mtlo $at
lw $at,EOFFSET_HI(\r)
mthi $at
lw $at,EOFFSET_STATUS(\r)
mtc0 $at, $status
lw $at,EOFFSET_EPC(\r)
mtc0 $at, $epc
lw $at,EOFFSET_AT(\r)
lw $sp,EOFFSET_SP(\r)
.endm
# Move kernel stack pointer address to register K0
# - if we are in user mode, load the appropriate stack
# address
.macro KERNEL_STACK_TO_K0
# If we are in user mode
mfc0 $k0, $status
andi $k0, 0x10
beq $k0, $0, 1f
add $k0, $sp, 0
# Move $k0 pointer to kernel stack
lui $k0, %hi(supervisor_sp)
ori $k0, $k0, %lo(supervisor_sp)
# Move $k0 (superveisor_sp)
lw $k0, 0($k0)
1:
.endm
.org 0x0
kernel_image_start:
/* Load temporary stack */
lui $sp, %hi(end_stack)
ori $sp, $sp, %lo(end_stack)
/* Not sure about this, but might be needed for PIC code???? */
lui $gp, 0x8000
jal main_bsp
nop
.space TEMP_STACK_SIZE
end_stack:
tlb_refill_entry:
j tlb_refill_handler
nop
cache_error_entry:
j cache_error_handler
nop
exception_entry:
j exception_handler
nop
exception_handler:
KERNEL_STACK_TO_K0
sub $k0, REGISTER_SPACE
REGISTERS_STORE $k0
add $sp, $k0, 0
add $a0, $sp, 0
jal exception /* exception(register_space) */
nop
REGISTERS_LOAD $sp
# The $sp is automatically restored to former value
eret
nop
tlb_refill_handler:
KERNEL_STACK_TO_K0
sub $k0, REGISTER_SPACE
REGISTERS_STORE $k0
add $sp, $k0, 0
add $a0, $sp, 0
jal tlb_refill /* tlb_refill(register_space) */
nop
REGISTERS_LOAD $sp
eret
nop
cache_error_handler:
KERNEL_STACK_TO_K0
sub $sp, REGISTER_SPACE
REGISTERS_STORE $sp
add $sp, $k0, 0
jal cache_error
nop
REGISTERS_LOAD $sp
eret
nop
userspace_asm:
add $sp, $a0, 0
eret
nop