45 lines
832 B
ArmAsm
45 lines
832 B
ArmAsm
#define SEG_KCODE 1 // kernel code
|
|
#define SEG_KDATA 2 // kernel data+stack
|
|
#define SEG_KCPU 3 // kernel per-cpu data
|
|
|
|
# vectors.S sends all traps here.
|
|
.globl alltraps
|
|
alltraps:
|
|
# Build trap frame.
|
|
pushl %ds
|
|
pushl %es
|
|
pushl %fs
|
|
pushl %gs
|
|
pushal
|
|
|
|
# Set up data and per-cpu segments.
|
|
movw $(SEG_KDATA<<3), %ax
|
|
movw %ax, %ds
|
|
movw %ax, %es
|
|
movw $(SEG_KCPU<<3), %ax
|
|
movw %ax, %fs
|
|
movw %ax, %gs
|
|
|
|
# Call trap(tf), where tf=%esp
|
|
pushl %esp
|
|
call trap
|
|
addl $4, %esp
|
|
|
|
# Return falls through to trapret...
|
|
.globl trapret
|
|
trapret:
|
|
popal
|
|
popl %gs
|
|
popl %fs
|
|
popl %es
|
|
popl %ds
|
|
addl $0x8, %esp # trapno and errcode
|
|
iret
|
|
|
|
# A forked process switches to user mode by calling
|
|
# forkret1(tf), where tf is the trap frame to use.
|
|
.globl forkret1
|
|
forkret1:
|
|
movl 4(%esp), %esp
|
|
jmp trapret
|
|
|