expand brk and assign it as HERE

1 files changed, 27 insertions, 2 deletions

diff --git a/jefs.s b/jefs.s
index 18e07f2..75ed89e 100644
--- a/jefs.s
+++ b/jefs.s
@@ -45,7 +45,7 @@
 %endmacro
 
 %assign smudge_mask	0x1
-%assign immemdiate_mask	0x2
+%assign immediate_mask	0x2
 
 %assign false 0x0
 %assign true 0xffffffffffffffff
@@ -71,6 +71,19 @@ _start:
 	; init
 	mov r14, wstack ; point SP to top
 
+	; EXPAND BRK
+	xor rdi, rdi ; brk syscall called with 0 gives the current brk
+	mov rax, __NR_brk
+	syscall
+	mov qword [here], rax
+	mov qword [h0], rax
+
+	add rax, 0x9c400 ; 640kb, entirely arbitrary
+	mov rdi, rax
+	mov rax, __NR_brk
+	syscall ; if this fails, have fun
+	mov qword [hend], rax
+
 	call interpret
 	mov rdi, 0
 	mov rax, __NR_exit
@@ -212,9 +225,21 @@ defword ">cfa", to_cfa, 0
 	pspush r11
 	ret
 
+defword "compile,", compile_comma, 0
+	ret
+
+defword ":", colon, 0
+	ret
+
+defword ";", semicolon, immediate_mask
+	ret
+
 defvar ">in", to_in, 0, 0
-defvar "latest", latest, 0, lfa_latest
 defvar "state", state, 0, interpreting
+defvar "here", here, 0, 0
+defvar "h0", h0, 0, 0 ; beginning of user memory area
+defvar "hend", hend, 0, 0 ; ending of user memory area
+defvar "latest", latest, 0, lfa_latest
 
 initfile:
 incbin "jefs.fs"