path: root/mu-init.subx

# Initialize the minimal runtime for Mu programs.
#
# See translate_mu for how this file is used.
#
# Mu programs start at a function called 'main' with this signature:
#   fn main args: (address array kernel-string) -> exit_status/ebx: int
# If your program doesn't need commandline arguments you can drop it:
#   fn main -> exit_status/ebx: int
#
# Notice that the output must be in ebx, so that the exit() syscall can pick
# it up.

== code

Entry:
    # we don't use ebp in Entry; just initialize it
    bd/copy-to-ebp 0/imm32
    # var args/eax: (address array kernel-string)
    89/<- %eax 4/r32/esp
    # initialize the heap
    (new-segment *Heap-size Heap)
    # run Mu program
    (main %eax)
    # exit
    (syscall_exit)