; entry.asm -- C process entry + call-throughs to the firmware socket API.
;
; _start replaces boot.obj (whose exit() spins and whose _c_int00 ends in
; `reti`): set up the C program stack, call main, return with `rets` to the
; create_process trampoline.
;
; The socket wrappers are NOT a bare `calla`/`rets`.  The firmware's wrappers
; end in `RETS 2`: they pop the return address *and* two argument words, and
; they restore A14 from a caller-pushed slot.  A plain thunk therefore returns
; with SP one word off, and its own `rets` pops the saved-A14 slot (a bit
; pointer into .bss) as the return address -- the CPU then executes data and
; the board lands in its reset/delay path.  dwt/tcpip/tftpc.asm avoids this by
; saving SP and A14 in cells around every ROM call; these thunks do the same.
;
;   socket   = 3F5C9A00h  socket(domain, type, protocol) -> fd
;   bind     = 3F5CAA80h  bind(fd, sockaddr*, len) -> 0 / -1
;   recvfrom = 3F5D7D50h  recvfrom(fd, buf, len, flags, &from, &fromlen) -> n
;   close    = 3F5E8930h  close(fd)
;   malloc   = 3F701230h  malloc(bytes) -> bit pointer
;   free     = 3F702440h  free(bit pointer)
;
; See dwt/notes/TCPIP.md.

	.text
	.globl	_start
	.globl	_main
_start:
	setf	32, 0, 1
	movi	_cstack, a14
	move	a14, a13
	calla	_main
	rets

	.globl	_socket_
_socket_:
	move	sp, @_sys_sp, 1
	move	a14, @_sys_a14, 1
	calla	3F5C9A00h
	move	@_sys_sp, sp, 1
	move	@_sys_a14, a14, 1
	rets	2

	.globl	_bind_
_bind_:
	move	sp, @_sys_sp, 1
	move	a14, @_sys_a14, 1
	calla	3F5CAA80h
	move	@_sys_sp, sp, 1
	move	@_sys_a14, a14, 1
	rets	2

	.globl	_recvfrom_
_recvfrom_:
	move	sp, @_sys_sp, 1
	move	a14, @_sys_a14, 1
	calla	3F5D7D50h
	move	@_sys_sp, sp, 1
	move	@_sys_a14, a14, 1
	rets	2

	.globl	_close_
_close_:
	move	sp, @_sys_sp, 1
	move	a14, @_sys_a14, 1
	calla	3F5E8930h
	move	@_sys_sp, sp, 1
	move	@_sys_a14, a14, 1
	rets	2

	.globl	_malloc_
_malloc_:
	move	sp, @_sys_sp, 1
	move	a14, @_sys_a14, 1
	calla	3F701230h
	move	@_sys_sp, sp, 1
	move	@_sys_a14, a14, 1
	rets	2

	.globl	_delay_
_delay_:
	move	sp, @_sys_sp, 1
	move	a14, @_sys_a14, 1
	calla	3F833A20h
	move	@_sys_sp, sp, 1
	move	@_sys_a14, a14, 1
	rets	2

	.globl	_listen_
_listen_:
	move	sp, @_sys_sp, 1
	move	a14, @_sys_a14, 1
	calla	3F5CBCD0h
	move	@_sys_sp, sp, 1
	move	@_sys_a14, a14, 1
	rets	2

	.globl	_accept_
_accept_:
	move	sp, @_sys_sp, 1
	move	a14, @_sys_a14, 1
	calla	3F5CCB40h
	move	@_sys_sp, sp, 1
	move	@_sys_a14, a14, 1
	rets	2

	.globl	_read_
_read_:
	move	sp, @_sys_sp, 1
	move	a14, @_sys_a14, 1
	calla	3F5D8E70h
	move	@_sys_sp, sp, 1
	move	@_sys_a14, a14, 1
	rets	2

	.globl	_select_
_select_:
	move	sp, @_sys_sp, 1
	move	a14, @_sys_a14, 1
	calla	3F871CE0h
	move	@_sys_sp, sp, 1
	move	@_sys_a14, a14, 1
	rets	2

	.globl	_free_
_free_:
	move	sp, @_sys_sp, 1
	move	a14, @_sys_a14, 1
	calla	3F702440h
	move	@_sys_sp, sp, 1
	move	@_sys_a14, a14, 1
	rets	2

	.bss	_cstack, 32768, 16	; 32768 bits = 4096 bytes
	.bss	_sys_sp, 32, 16
	.bss	_sys_a14, 32, 16
	.end