filemgmt.asm

<虚拟机的设计与实现>一书中hec虚拟机的源代码

.PB main
.PV filename1  -16
.PV filename2 -32
.PV dirname   -40
.PV buffer    -512

#allocate local storage
PUSHQ $FP
MOV $FP,$SP
LQI $R7,512
SUB $SP,$SP,$R7

#populate local dirName = C:\
LAI $R10,$FP,dirname
MOV $R14,$R10
LBI $R2,1

LBI $R1,'C'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,':'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'\'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'_'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'a'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,0
SB  $R1,$R10

#populate local filename1 = C:\_a\t.txt
LAI $R10,$FP,filename1
MOV $R11,$R10
LBI $R2,1

LBI $R1,'C'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,':'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'\'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'_'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'a'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'\'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'t'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'.'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'t'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'x'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'t'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,0
SB  $R1,$R10

#populate local filename2 = C:\_a\w.txt
LAI $R10,$FP,filename2
MOV $R12,$R10
LBI $R2,1

LBI $R1,'C'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,':'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'\'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'_'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'a'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'\'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'w'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'.'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'t'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'x'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,'t'
SB  $R1,$R10
ADD $R10,$R10,$R2

LBI $R1,0
SB  $R1,$R10

#check to see if file exists and print return code
LBI $R1,0
MOV $R2,$R11
INT 1

MOV $R2,$R3
LBI $R1,20
INT 0

LQI $R2,10
LQI $R1,16
INT 0
LQI $R2,13
LQI $R1,16
INT 0

#check to see if filename1 is a directory
MOV $R2,$R11
LBI $R1,1
INT 1

MOV $R2,$R3
LBI $R1,20
INT 0

LQI $R2,10
LQI $R1,16
INT 0
LQI $R2,13
LQI $R1,16
INT 0

#check to see if can read file
LBI $R1,2
MOV $R2,$R11
INT 1

MOV $R2,$R3
LBI $R1,20
INT 0

LQI $R2,10
LQI $R1,16
INT 0
LQI $R2,13
LQI $R1,16
INT 0

#check to see if can write to file
LBI $R1,3
MOV $R2,$R11
INT 1

MOV $R2,$R3
LBI $R1,20
INT 0

LQI $R2,10
LQI $R1,16
INT 0
LQI $R2,13
LQI $R1,16
INT 0

#get size of a file in bytes
LBI $R1,4
MOV $R2,$R11
INT 1

MOV $R2,$R3
LBI $R1,20
INT 0

LQI $R2,10
LQI $R1,16
INT 0
LQI $R2,13
LQI $R1,16
INT 0

#get time of last modification of file
LBI $R1,5
MOV $R2,$R11
INT 1

MOV $R2,$R3
LBI $R1,20
INT 0

LQI $R2,10
LQI $R1,16
INT 0
LQI $R2,13
LQI $R1,16
INT 0

#delete a file
LBI $R1,6
MOV $R2,$R11
INT 1

MOV $R2,$R3
LBI $R1,20
INT 0

LQI $R2,10
LQI $R1,16
INT 0
LQI $R2,13
LQI $R1,16
INT 0

#create a directory
LBI $R1,7
MOV $R2,$R12
INT 1

MOV $R2,$R3
LBI $R1,20
INT 0

LQI $R2,10
LQI $R1,16
INT 0
LQI $R2,13
LQI $R1,16
INT 0

#delete a directory
LBI $R1,8
MOV $R2,$R12
INT 1

MOV $R2,$R3
LBI $R1,20
INT 0

LQI $R2,10
LQI $R1,16
INT 0
LQI $R2,13
LQI $R1,16
INT 0

#obtain the full path of file
LBI $R1,9
LAI $R3,$FP,buffer
MOV $R13,$R3
MOV $R2,$R12
INT 1

MOV $R2,$R13
LBI $R1,18
INT 0

LQI $R2,10
LQI $R1,16
INT 0
LQI $R2,13
LQI $R1,16
INT 0

#get the maximum path length
LBI $R1,10
INT 1

LBI $R1,20
INT 0

LQI $R2,10
LQI $R1,16
INT 0
LQI $R2,13
LQI $R1,16
INT 0

#get the contents of C:\_a
LBI $R1,11
MOV $R2,$R14
LBI $R3,0
MOV $R4,$R13
INT 1

MOV $R2,$R13
LBI $R1,18
INT 0

LQI $R2,10
LQI $R1,16
INT 0
LQI $R2,13
LQI $R1,16
INT 0

#rename w.txt to t.txt
LBI $R1,12
MOV $R2,$R12
MOV $R3,$R11
INT 1

#reclaim local storage
MOV $SP,$FP
POPQ $FP

HALT
.PE