serial: Use launch_fxf_from_disk

applications/serial/main.asm

@@ -1,10 +1,18 @@
 ; serial terminal - spawn sh.fxf on the serial port
 
     ; start an instance of sh.fxf
-    call get_unused_task_id
+    call get_current_disk_id
+    mov r1, r0
+    mov r0, sh_fxf_name
+    mov r2, stream_struct
+    mov r3, 0
+    mov r4, 0
+    mov r5, 0
+    mov r6, 0
+    call launch_fxf_from_disk
+    cmp r0, 0xFFFFFFFF
+    ifz call end_current_task
     mov.8 [shell_task_id], r0
-    mov r1, stream_struct
-    call new_shell_task
 
 event_loop:
     movz.8 r0, [shell_task_id]
@@ -37,6 +45,7 @@ stream_struct:
     data.32 stream_write
 
 shell_task_id: data.8 0
+sh_fxf_name: data.strz "sh.fxf"
 
 stream_read:
     in r0, 0
@@ -56,7 +65,5 @@ stream_write_special:
     pop r0
     ret
 
-
-#include "../terminal/task.asm"
     #include "../../../fox32rom/fox32rom.def"
     #include "../../fox32os.def"