cc65/libsrc/joystick/joy_load.s

122 lines
3.0 KiB
ArmAsm

;
; Ullrich von Bassewitz, 2006-06-05
;
; unsigned char __fastcall__ joy_load_driver (const char* driver);
; /* Load and install a joystick driver. Return an error code. */
.include "joy-kernel.inc"
.include "joy-error.inc"
.include "modload.inc"
.include "fcntl.inc"
.import pushax
.import pusha0
.import incsp2
.import _open
.import _read
.import _close
;----------------------------------------------------------------------------
; Variables
.data
ctrl: .addr _read
.res 2 ; CALLERDATA
.res 2 ; MODULE
.res 2 ; MODULE_SIZE
.res 2 ; MODULE_ID
;----------------------------------------------------------------------------
; Code
.code
.proc _joy_load_driver
; Save name on the C stack. We will need it later as parameter passed to open()
jsr pushax
; Check if we do already have a driver loaded. If so, remove it.
lda _joy_drv
ora _joy_drv+1
beq @L1
jsr _joy_uninstall
; Open the file. The name parameter is already on stack and will get removed
; by open().
; ctrl.callerdata = open (name, O_RDONLY);
@L1: lda #<O_RDONLY
jsr pusha0
ldy #4 ; Argument size
jsr _open
sta ctrl + MOD_CTRL::CALLERDATA
stx ctrl + MOD_CTRL::CALLERDATA+1
; if (ctrl.callerdata >= 0) {
txa
bmi @L3
; /* Load the module */
; Res = mod_load (&ctrl);
lda #<ctrl
ldx #>ctrl
jsr _mod_load
pha
; /* Close the input file */
; close (ctrl.callerdata);
lda ctrl + MOD_CTRL::CALLERDATA
ldx ctrl + MOD_CTRL::CALLERDATA+1
jsr _close
; /* Check the return code */
; if (Res == MLOAD_OK) {
pla
bne @L3
; Check the driver signature, install the driver. c is already on stack and
; will get removed by joy_install().
; Res = joy_install (ctrl.module);
lda ctrl + MOD_CTRL::MODULE
ldx ctrl + MOD_CTRL::MODULE+1
jsr _joy_install
; If joy_install was successful, we're done
tax
beq @L2
; The driver didn't install correctly. Remove it from memory and return the
; error code.
pha ; Save the error code
lda _joy_drv
ldx _joy_drv+1
jsr _mod_free ; Free the driver memory
jsr _joy_clear_ptr ; Clear joy_drv
pla ; Restore the error code
ldx #0 ; We must return an int
@L2: rts ; Done
; Open or mod_load failed. Return an error code.
@L3: lda #<JOY_ERR_CANNOT_LOAD
ldx #>JOY_ERR_CANNOT_LOAD
rts
.endproc