fox32os/kernel/shell/launch.asm

108 lines
2.7 KiB
NASM

; FXF launcher helper routines
; launch an FXF binary from a shell entry
; inputs:
; r0-r3: shell arguments
; outputs:
; none, does not return if task started successfully
; returns if FXF file not found
launch_fxf:
; clear the first 8 characters of the launch_fxf_name buffer
push r0
mov r0, launch_fxf_spaces
mov r1, launch_fxf_name
mov r2, 8
call copy_memory_bytes
pop r0
; copy the name into the launch_fxf_name buffer
mov r1, launch_fxf_name
mov r31, 8
launch_fxf_name_loop:
mov.8 [r1], [r0]
inc r0
inc r1
cmp.8 [r0], 0
ifz jmp launch_fxf_name_loop_done
loop launch_fxf_name_loop
launch_fxf_name_loop_done:
; open the file
mov r0, launch_fxf_name
movz.8 r1, [shell_current_disk]
mov r2, launch_fxf_struct
call ryfs_open
cmp r0, 0
ifz ret
; allocate memory for the binary
mov r0, launch_fxf_struct
call ryfs_get_size
call allocate_memory
cmp r0, 0
ifz jmp allocate_error
mov [launch_fxf_binary_ptr], r0
; read the file into memory
mov r0, launch_fxf_struct
mov r1, [launch_fxf_binary_ptr]
call ryfs_read_whole_file
; allocate a 64KiB stack
mov r0, 65536
call allocate_memory
cmp r0, 0
ifz jmp allocate_error
mov [launch_fxf_stack_ptr], r0
; push the argument pointers and terminal stream struct pointer to the task's stack
call shell_parse_arguments
mov r4, rsp
mov rsp, [launch_fxf_stack_ptr]
add rsp, 65536 ; point to the end of the stack (stack grows down!!)
push r3
push r2
push r1
push r0
push [shell_terminal_stream_struct_ptr]
sub rsp, 65516
mov [launch_fxf_stack_ptr], rsp
mov rsp, r4
; relocate the binary
mov r0, [launch_fxf_binary_ptr]
call parse_fxf_binary
; create a new task
mov r1, r0
call get_unused_task_id
mov.8 [launch_fxf_task_id], r0
mov r2, [launch_fxf_stack_ptr]
add r2, 65516 ; point to the end of the stack (stack grows down!!)
mov r3, [launch_fxf_binary_ptr]
mov r4, [launch_fxf_stack_ptr]
call new_task
; fall-through to launch_fxf_yield_loop
; loop until the launched task ends
launch_fxf_yield_loop:
movz.8 r0, [launch_fxf_task_id]
call is_task_id_used
ifz jmp shell_task_return
call yield_task
rjmp launch_fxf_yield_loop
allocate_error:
mov r0, out_of_memory_string
call print_str_to_terminal
ret
launch_fxf_name: data.str " fxf"
launch_fxf_spaces: data.str " "
launch_fxf_struct: data.32 0 data.32 0
launch_fxf_task_id: data.8 0
launch_fxf_binary_ptr: data.32 0
launch_fxf_stack_ptr: data.32 0
out_of_memory_string: data.str "failed to allocate for new task!" data.8 10 data.8 0