;
; mem.s
;
; Generic memory allocation for TermScript
;
; © 1995 Straylight
;

;----- Standard Header ------------------------------------------------------

		GET	libs:header
		GET	libs:swis

		GET	libs:stream

;----- External dependencies ------------------------------------------------

		GET	sh.errNum
		GET	sh.error

;----- Main code ------------------------------------------------------------

		AREA	|TermScript$$Code|,CODE,READONLY

; --- mem_alloc ---
;
; On entry:	R0 == size of block to allocate
;
; On exit:	R0 == pointer to anchor for that block
;		May return an error
;
; Use:		Tries to allocate a block of memory, and returns a pointer
;		to the anchor for that block. All very unusual really,
;		but we blame Wimp_Extension which allocates anchors for
;		you in an utterley horrible way.


		EXPORT	mem_alloc
mem_alloc	ROUT

		; --- For now, we will use the RMA ---

		STMFD	R13!,{R1-R3,R14}
		ADD	R3,R0,#4
		MOV	R0,#6
		SWI	XOS_Module
		BVS	%99mem_alloc
		ADD	R3,R2,#4
		STR	R3,[R2,#0]
		MOV	R0,R2
		LDMFD	R13!,{R1-R3,PC}^

99mem_alloc	MOV	R0,#err_noMem
		B	error_report

		LTORG

; --- mem_free ---
;
; On entry:	R0 == anchor of the block to free
;
; On exit:	--
;
; Use:		Frees the block.

		EXPORT	mem_free
mem_free	ROUT

		STMFD	R13!,{R0-R2,R14}
		LDR	R2,[R0,#0]
		SUB	R2,R2,#4
		MOV	R0,#7
		SWI	OS_Module
		LDMFD	R13!,{R0-R2,PC}^

		LTORG

; --- mem_realloc ---
;
; On entry:	R0 == pointer to block anchor
;		R1 == new size requested
;
; On exit:	May return an error
;
; Use:		Resizes a block

		EXPORT	mem_realloc
mem_realloc	ROUT

		MOV	R0,#err_realloc
		B	error_report

		LTORG

;----- That's all, folks ----------------------------------------------------

		END