55 lines
977 B
ArmAsm
55 lines
977 B
ArmAsm
" Test program for several system calls: open, read, write, close, exit
|
|
" Do:
|
|
" ./as7 write_test.s > a.out
|
|
" ./a7out -d a.out
|
|
main:
|
|
" Test the lac, dac instructions
|
|
lac in
|
|
dac out
|
|
|
|
" Write hello to fd1 i.e stdout
|
|
lac d1
|
|
sys write; hello; 7
|
|
|
|
" open file fred
|
|
sys open; fred; 0; 0
|
|
|
|
" read 5 words into the buffer from stdin: type in 10 or more characters!
|
|
lac d0
|
|
sys read; buf; 5
|
|
|
|
" Stop and dump memory, so you can see five words at location 0400
|
|
" Comment out the hlt instruction to test close and exit
|
|
hlt
|
|
|
|
" close stdin
|
|
lac d0
|
|
sys close
|
|
|
|
" exit
|
|
sys exit
|
|
|
|
" We should not get to the halt instruction
|
|
hlt
|
|
|
|
|
|
" Some memory locations for lac and dac
|
|
. = 0100
|
|
in: 023
|
|
|
|
. = 0200
|
|
out: 0
|
|
|
|
" Hello, world\n, two ASCII chars per word
|
|
hello: 0110145; 0154154; 0157054; 040; 0167157; 0162154; 0144012
|
|
|
|
" fred as a string, NUL terminated
|
|
fred: 0146162; 0145144; 0
|
|
|
|
" Input buffer for read
|
|
. = 0400
|
|
buf: 0
|
|
|
|
d0: 0
|
|
d1: 1
|