Enhancement of elf generation

Now addresses are absolutre from the elf code start => JIT do not
work anymore

bfc.asm

@@ -34,22 +34,33 @@ ALIGNMODE k8
 %define MAP_INC_MASK 0x0FFF
 %define BFMEM_INIT_SZ MAP_INC_SIZE
 
+%define ELF_CODE_OFFSET 0x00400080
+
 section .data
 
-	bf_start_head:
-		push 0x00400085
-		;dw 0x6885004000
-	bf_start_head_sz: equ $ - bf_start_head
 	bf_start:
 		jmp .start
-		.mremap: ; rbx is resize size
-			cmp rbx, MAP_INC_SIZE
-			jg .remap_cont
-			xor rbx, rbx
-			.remap_cont:
-			xor rbx, MAP_INC_MASK
-			add rbx, MAP_INC_SIZE
-			add r14, rbx
+		.mremap:
+			; Resize the mmap
+			;   rbx is resize min size
+			;   rdi is map ptr offset
+			;   r14 is map_len
+			;   r15 is map_addr
+			; Returns :
+			;   r15 new map_addr
+			;   r14 new map_len
+			;   rdi map ptr offset
+			;   rsi map ptr
+			push rdi
+
+			; set min resize
+			xor rdx, rdx
+			.loop_min_remap:
+				add rdx, MAP_INC_SIZE
+				cmp rdx, rbx
+				jl .loop_min_remap
+			add r14, rdx ; newlen
+
 			mov rax, 0x19	; mremap
 			mov rdi, r15	; addr
 			mov rsi, r14 	; oldlen
@@ -61,6 +72,10 @@ section .data
 			cmp rax, 0
 			jle .erremap
 			mov r15, rax
+			; restore rsi & rdi
+			pop rdi
+			mov rsi, r15
+			add rsi, rdi
 			ret
 			.erremap:
 				mov rax, 0x3c
@@ -68,23 +83,55 @@ section .data
 				syscall
 			align 8
 		.lbl_incresize: equ $ - bf_start
-		.incresize: ; rbx is resize size
+
+		.incresize:
+			; Resize the map on ptr increment
+			;   rbx is increment count
+			;   rdi is map ptr offset
+			;   r14 is map_len
+			;   r15 is map_addr
 			call .mremap
 			ret
 			align 8
 		.lbl_decresize: equ $ - bf_start
-		.decresize: ; rbx is decrement
-			push rsi
-			push r14
+
+		.decresize:
+			; Resize the map on ptr decrement
+			;   rbx is decrement count
+			;   rdi is map ptr offset
+			;   r14 is map_len
+			;   r15 is map_addr
+			; Note : data has to be shifted
+			push r14 ; old map len
 			call .incresize
-			pop rcx ; old size
+			; shift datas
+			pop rcx ; old len
+			mov rbx, r14 ; new_len
+			push rsi
+			push rdi
+			mov rsi, r15
 			mov rdi, rsi
-			inc rdi
-			.decresize_cpy:
+			add rsi, rcx ; add old_len to map_ptr
+			add rdi, rbx ; add new_len to map_ptr
+			sub rbx, rcx ; new_len - old_len : resize
+			std ; set DF to dec rsi & rdi
+			.decresize_shift:
 				movsb
-				loop .decresize_cpy
-			mov byte [r15], 0
+				loop .decresize_shift
+			; set first map bytes to 0
+			mov rdi, r15
+			add rdi, rbx
+			dec rdi
+			mov rcx, rbx
+			.decresize_zeros:
+				mov byte [rdi], 0x0
+				dec rdi
+				loop .decresize_zeros
+			pop rdi
 			pop rsi
+			; update map_ptr & offset given the shift
+			add rdi, rbx
+			add rsi, rbx
 			ret
 		.errmap:
 			mov rax, 0x3c
@@ -103,67 +150,74 @@ section .data
 		syscall
 		cmp rax, 0
 		jle .errmap
-		mov r15, rax
+
+		; Sets BF runtime :
+		; r14 is map len
+		mov r15, rax ; r15 is map addr
+		mov rdi, (BFMEM_INIT_SZ / 2) ; rdi is ptr idx
 		mov rsi, r15
-		add rsi, (BFMEM_INIT_SZ / 2) ; BF ptr
+		add rsi, rdi ; rsi is bf ptr
 		align 8
 	bf_start_sz: equ $ - bf_start
 
 	
-	; In piece of code call jump is achieved by adding
-	; an offset to the JIT map base addr
-	; this base address has to be on top of the stack
-	; when executing this small piece of code
-	;
-	; the first instruction has to be a mov of a byte
-	; in a register. This operation will be updated to
-	; "pass" a parameter
+	; In piece of code the first instruction has to be a mov of
+	; a quadword in a register. This operation will be updated
+	; to "pass" a parameter
+	;   rsi is map_ptr
+	;   rdi is map ptr offset
+	;   r14 is map_len
+	;   r15 is map_addr
+
 	bf_decptr:
+		; dec map ptr
+		;	rbx is dec count
 		mov rbx, strict qword 0x1
 		push rbx
-		cmp rsi, rbx
+		cmp rdi, rbx
 		jge .end
-		mov rax, [rsp+8]
-		add rax, bf_start.lbl_decresize
+		mov rax, ELF_CODE_OFFSET + bf_start.lbl_decresize
 		call rax
+		;call (ELF_CODE_OFFSET + bf_start.lbl_decresize)
 		.end:
 		pop rbx
 		sub rsi, rbx
+		sub rdi, rbx
 	bf_decptr_sz: equ $ - bf_decptr
 
 	bf_incptr:
 		mov rbx, strict qword 0x1
 		push rbx
-		mov rax, rsi
-		sub rax, r15
-		cmp rax, r14
-		jl .end
-		mov rax, [rsp+8]
-		add rax, bf_start.lbl_incresize
+		add rbx, rdi
+		cmp rdi, r14
+		jge .end
+		mov rbx, [rsp]
+		mov rax, ELF_CODE_OFFSET + bf_start.lbl_incresize
 		call rax
+		;call (ELF_CODE_OFFSET + bf_start.lbl_incresize)
 		.end:
 		pop rbx
 		add rsi, rbx
+		add rdi, rbx
 	bf_incptr_sz: equ $ - bf_incptr
 
 	bf_incval:
 		mov rbx, strict qword 0x1
-		xor rax, rax
 		mov al,[rsi]
-		add rax, rbx
+		add al, bl
 		mov [rsi], al
 	bf_incval_sz: equ $ - bf_incval
 
 	bf_decval:
 		mov rbx, strict qword 0x1
-		xor rax, rax
 		mov al, [rsi]
-		sub rax, rbx
+		sub al, bl
 		mov [rsi], al
 	bf_decval_sz: equ $ - bf_decval
 
 	bf_readval:
 		mov rdx, strict qword 0x1
+		push rdi
 		push rsi
 		xor rax, rax ; read
 		xor rdi, rdi ; stdin
@@ -173,22 +227,28 @@ section .data
 		mov byte [rsi], 0
 		.end:
 		pop rsi
+		pop rdi
 	bf_readval_sz: equ $ - bf_readval
 
 	bf_writeval:
-		mov rdx, strict qword 0x1
+		mov rcx, strict qword 0x1
+		push rdi
 		push rsi
-		xor rax, rax ; write
-		inc rax
-		mov rdi, rax ; stdout
-		syscall
+		.loop_write:
+			push rcx
+			mov rax, 1 ; write
+			mov rdi, rax ; stdout
+			mov rsi, [rsp+8]
+			mov rdx, 1 ; 1 chr
+			syscall
+			pop rcx
+			loop .loop_write
 		pop rsi
+		pop rdi
 	bf_writeval_sz: equ $ - bf_writeval
 
 	bf_loopstart:
 		mov rbx, strict qword 0x1
-		add rbx, [rsp]
-		xor rdx, rdx
 		mov dl, [rsi]
 		cmp dl, 0
 		jnz .end
@@ -198,8 +258,6 @@ section .data
 
 	bf_loopend:
 		mov rbx, strict qword 0x1
-		add rbx, [rsp]
-		xor rdx, rdx
 		mov dl, [rsi]
 		cmp dl, 0
 		jz .end
@@ -403,7 +461,6 @@ _start:
 
 	.write_elf: ; writing elf file
 	mov rax, [rsp] ; map len
-	add rax, bf_start_head_sz
 	mov [elf_section_text_sz], rax
 	add rax, elf_head_sz ; elf head + map_ptr
 	mov [elf_head + 0x60], rax
@@ -439,12 +496,6 @@ _start:
 	mov rdx, elf_head_sz
 	syscall
 
-	mov rax, 1
-	mov rdi, [rsp]
-	mov rsi, bf_start_head
-	mov rdx, bf_start_head_sz
-	syscall
-
 	mov rax, 1
 	mov rdi, [rsp]
 	mov rsi, r15 ; map_addr
@@ -769,15 +820,24 @@ compile_bf:
 			push rdx
 			call code_cpy
 			mov map_ptr, rax ; rax is map_ptr
-			pop rdx
-			sub rax, rdx
-			add rax, 2 ;arg addr in code map
+			mov rdi, rax
+			pop rdx ; bf_loopend_sz
+			lea rdi, [rax + 2]
+			sub rdi, rdx ; arg addr for loop_end : map_ptr - loopend_sz
+
 			pop rbx ; loop_start code offset
-			mov [rax], rbx ; loop end jump to start
+
+			lea rax, [rbx+ELF_CODE_OFFSET] ; jmp to loop_start in loop_end
+			mov [rdi], rax
+			.br1:
+
 			mov rax, map_ptr
-			sub rax, r15 ; loop end offset in map
-			add rbx, r15 ; loop start addr
-			mov [rbx+2], rax ; start jump to end
+			sub rax, r15 ; map_ptr - map_addr : map_offset of loop_end nxt instr
+			lea rdi, [rbx + r15 + 2] ; arg addr for loop_start in map
+			lea rax, [rax + ELF_CODE_OFFSET]
+			.br2:
+			mov [rdi], rax
+			.br3:
 			jmp .nxtinstr
 
 		.callcpy: