; mailbox.inc - fixed test mailbox shared by the compiler, generated
; programs, and the x128 harness. Protocol: docs/memory-map.md.
;
; The mailbox is in bank 0 inside bottom common RAM, so it is readable and
; writable from every Nova128 mapping and from the VICE monitor after exit.

.ifndef MAILBOX_INC
MAILBOX_INC = 1

MB_BASE         = $1BF0
MB_MAGIC0       = MB_BASE + 0   ; 'N' ($4E) once the mailbox is initialized
MB_MAGIC1       = MB_BASE + 1   ; '8' ($38)
MB_PRODUCER     = MB_BASE + 2   ; who wrote it (MB_PROD_*)
MB_STATUS       = MB_BASE + 3   ; MB_ST_*
MB_CODE         = MB_BASE + 4   ; 2 bytes LE: diagnostic/fault/check code
MB_ADDR         = MB_BASE + 6   ; 2 bytes LE: fault or check address
MB_DATA         = MB_BASE + 8   ; 8 bytes producer-defined payload
MB_SIZE         = 16

MB_MAGIC0_VALUE = $4E
MB_MAGIC1_VALUE = $38

MB_PROD_PLATFORM = $01          ; platform probe/skeleton
MB_PROD_COMPILER = $02          ; N128C
MB_PROD_PROGRAM  = $03          ; generated Nova128 program

MB_ST_RUNNING   = $01           ; written first; still set => hung or crashed
MB_ST_PASS      = $A5
MB_ST_FAIL      = $FA

.endif