.text
.align 2
ev_size=16
evdata_len=ev_size*4
.macro syswrite @ print the content of r1, must be ascii, buffer length r2 must be set
push {r0, r7}
mov r7, #4 @ system call number, 4 is 'write'
mov r0, #1 @ file descriptor 1 - stdout
svc 0 @ call the Linux kernel and print the ascii text
pop {r0, r7}
.endm
.macro syswritechar @ print what r1 points at, must be ascii, buffer length r2 must be set
push {r0, r2, r7}
mov r2, #1
mov r7, #4 @ system call number, 4 is 'write'
mov r0, #1 @ file descriptor 1 - stdout
svc 0 @ call the Linux kernel and print the ascii text
pop {r0, r2, r7}
.endm
.macro newline
ldr r1, =newline @ point on the buffer to write, \n, a newline
mov r2, #2 @ newline buffer length
syswrite
.endm
.global _start
_start:
getkey:
mov r2,#evdata_len
ldr r1, =evdata_ofs
sub r0, r0, r0
@ Clear evdata to evdata_len of zeroes
@ Set r0 to 'keyp' i.e. 0x7079656b (assuming I've got my endianness correct)
mov r7, #3
svc 0 @ Do sys_read
cmp r0, #ev_size
bge getkey_ok
@ Set r0 to 'gpio' i.e. 0x6f697067
svc 0 @ Do sys_read again, this time on gpio signals??
cmp r0,#ev_size
@ if lt, mov r0, #0 ; return - no key pressed
getkey_ok:
@ Got a valid key event
ldrh r2, [r1, #8]
ldrh r0, [r1, #10]
ldr r3, [r1, #12]
@ if r2==1 (#ev_key) and r3==1 (#ev_press), return key code in r0, else mov r0, #0 and return
newline
_disp_hex:
ldr r1, =asciicounter @ point on =asciicounter
mov r2, r0
mov r3, #15
mov r4, #8
_loop:
mov r2, r2, ror #28
and r5, r2, r3
cmp r5, #9
add r5, #48
ble _num
add r5, #7
_num:
str r5, [r1]
syswritechar
subs r4, #1
bne _loop
newline
mov r7, #1 @ exit
svc 0 @ call the Linux kernel and exit
.data
asciicounter: .word 0 @ must be initialized
newline: .asciz "\n" @ \n is a newline
evdata: .fill evdata_len,1,0
evdata_ofs: .word evdata.title "evlist"
.arm
.include "macro.mac"
evdatalen=0x20
.data
evdev: .ascii "/dev/input/event"
evnum: .byte 0xff,0
evnamelen=.-evdev-1
.align
.text
eviocgname: .word ioc_read | ((evdatalen-1) << 16) | 0x4506
evdevofs: .word evdev
evdataofs: .word evdata
.globl _start
_start:
ldr r4,evdevofs
mov r5,#'0'
ev_scan_loop:
mov r1,#o_rd
mov r0,r4
strb r5,[r4,#(evnum-evdev)]
invoke sys_open
# r0=fd
subs r3,r0,#0
bpl 1f
exit 0xff
1:
mov r0,#console
mov r1,r4
mov r2,#(evnamelen)
invoke sys_write
mov r0,#' '
bl printchar
ldr r1,eviocgname
mov r0,r3
ldr r2,evdataofs
invoke sys_ioctl
mov r1,r2
mov r2,r0
mov r0,#console
invoke sys_write
mov r0,r3
invoke sys_close
mov r0,#'\n'
bl printchar
inc r5
b ev_scan_loop
printchar:
push {r0-r2,r7,lr}
mov r0,#console
mov r1,sp
mov r2,#1
invoke sys_write
pop {r0-r2,r7,pc}
.bss
evdata: .fill evdatalen,1,0
.align
.endcat /dev/input/event0 | hexdump.title "evlist"
.arm
.include "macro.mac"
ifpandora=1
.if ifpandora
.else
key_q=0x10 @ for alarm/zaurus
.endif
evdatalen=ev_size
.data
evdev: .ascii "/dev/input/event"
evnum: .byte 0xff,0
evnamelen=.-evdev-1
.align
.text
eviocgname: .word ioc_read | ((evdatalen-1) << 16) | 0x4506
evdevofs: .word evdev
evdataofs: .word evdata
.globl _start
_start:
ldr r4,evdevofs
mov r5,#'0'
ev_scan_loop:
mov r1,#o_rd | o_nonblock
mov r0,r4
strb r5,[r4,#(evnum-evdev)]
invoke sys_open
@ r0=fd
subs r3,r0,#0
bpl 1f
exit 0xff
txt_keypad:
.if ifpandora
.ascii "keyp" @ "keypad"
.else
.ascii "matr" @ "matrix-keypad"
.endif
1:
ldr r1,eviocgname
mov r0,r3
ldr r2,evdataofs
invoke sys_ioctl
ldr r0,[r2]
ldr r1,txt_keypad
cmp r0,r1
beq 2f
mov r0,r3
invoke sys_close
inc r5
b ev_scan_loop
2:
print "keypad event found\nlet's read it..."
1:
mov r0,r3
ldr r1,evdataofs
mov r2,#evdatalen
invoke sys_read
cmp r0,#ev_size
blt 1b
ldrh r2,[r1,#ev_type]
ldr r4,[r1,#ev_value]
ldrh r0,[r1,#ev_code]
cmp r2,#ev_key
cmpeq r4,#ev_press
cmpeq r0,#key_q
bne 1b
print "\n'q' was pressed. bye\n"
mov r0,r3
invoke sys_close
exit 0
.bss
evdata: .fill evdatalen,1,0
.align
.end@ the usual init stuff goes here
.title "evlist"
.arm
.include "macro.mac"
ifpandora=1 @ i was writing this code on a zaurus. that's why it's here.
.if ifpandora
.else
key_q=0x10 @ 'q' key scancode for alarm/zaurus
.endif
evdatalen=ev_size @ event size is 16 bytes
.data
evdev: .ascii "/dev/input/event"
evnum: .byte 0xff,0 @ we will update the 0xff byte with the event's number
evnamelen=.-evdev-1
.align
.bss
evdata: .fill evdatalen,1,0 @ allocate 16 bytes in uninitialized data section .bss
.text
@ defined in linux/inluput.h
@ #define EVIOCGNAME(len) _IOC(_IOC_READ, 'E', 0x06, len) /* get device name */
eviocgname: .word ioc_read | ((evdatalen-1) << 16) | 0x4506
evdevofs: .word evdev @ store evdev's offset for easier access
evdataofs: .word evdata @ store evdata's offset for easier access
.globl _start
_start:
ldr r4,evdevofs @ similar to "ldr r4,=evdev". if we won't store
@ the address then GAS will do it using a literal pool
mov r5,#'0' @ the first device to open will be "/dev/input/event0"
ev_scan_loop:
mov r1,#o_rd | o_nonblock
@ open the device for reading without
@ waiting to fill the buffer. R0 will return 0 if no input.
mov r0,r4 @ device name
strb r5,[r4,#(evnum-evdev)]
@ the string will look "/dev/input/event0"
@ after writing R5 to the one before last character. "evnum" is ASCIIZ
invoke sys_open @ try to open it
subs r3,r0,#0 @ store the device handle to R3 for later use.
@ note: a regular syscall trashes r0 and some times r1 and/or r2.
bpl 1f @ branch if the file was opened successfully
exit 0xff @ exit if we run out of devices
txt_keypad:
.if ifpandora
.ascii "keyp" @ "keypad"
.else
.ascii "matr" @ "matrix-keypad"
.endif
1:@ get the event's name using a syscall EVIOCGNAME
ldr r1,eviocgname
mov r0,r3 @ use the opened event's handle
ldr r2,evdataofs @ store the result in evdata. we use the
@ same memory block to store the name and to
@ read the event data later.
invoke sys_ioctl
ldr r0,[r2] @ compare if the name was 'keypad'. we compare the
@ first four characters.
ldr r1,txt_keypad
cmp r0,r1
beq 2f
mov r0,r3 @ if it was not 'keyp' then close the device and
invoke sys_close
inc r5 @ move to the next event, '0'..'1'..'2'.. and so on
b ev_scan_loop
2:
print "keypad event found\nlet's read it..."1:
mov r0,r3 @ event handle is still stored in R3
ldr r1,evdataofs
mov r2,#evdatalen @ read the event handle and store the data into evdata
invoke sys_read @ we read 16 bytes in one run
cmp r0,#ev_size @ if we got less then 16 bytes then do the read loop again
blt 1b
ldrh r2,[r1,#ev_type] @ read the event type,
ldr r4,[r1,#ev_value] @ value
ldrh r0,[r1,#ev_code] @ and code from the 16 byte long buffer.
@ (we don't need the timestamp data)
cmp r2,#ev_key @ if it was a KEY event
cmpeq r4,#ev_press @ with a PRESSED key
cmpeq r0,#key_q @ and the key was 'Q'
bne 1b @ then print out the following message.
@ otherwise branch back to the read loop
print "\n'q' was pressed. bye\n"
mov r0,r3
invoke sys_close @ close the handle
exit 0 @ and exit
.end
