Index: kcore/boot.rt.c
==================================================================
--- kcore/boot.rt.c
+++ kcore/boot.rt.c
@@ -1,14 +1,17 @@
 #include <k/core.h>
 extern stat entry(kenv);
 
-stat _boot(unsigned int argc, char** argv) {
+unsigned long long
+_boot(unsigned int argc, /* argument count */
+		char** argv, /* arguments */
+		char** envp /* environment */ ) {
 	kenv e = { 
-		// todo: determine terminal class and set term vs ansi correctly!
+		/* TODO: determine terminal class and set term vs ansi correctly! */
 		{ {kiostream_term, 0}, {kiostream_term, 1} }, // chan std
 		{ {kiostream_closed},  {kiostream_term, 2} }, // chan err
-		argc, argv,
-		null // no environment yet
+		argc, argv, 
+		null // needs parsing
 	};
 	return entry(e);
 }
 	

Index: kcore/boot.rt.x86.lin.64.s
==================================================================
--- kcore/boot.rt.x86.lin.64.s
+++ kcore/boot.rt.x86.lin.64.s
@@ -4,14 +4,64 @@
 global _start:function
 extern _boot
 extern entry
 
 _start:
-	mov rbp, rsp
-	mov rdi, [rbp + 0] ; argc
-	lea rsi, [rbp + 8] ; argv
+	mov rbp, 0 ; zero the stack base ptr.
+	; attempted fix for a difficult-to-
+	; reproduce bug
+
+	mov rdi, 0 ; zero rdi - because argc
+	; is 32 bits long, we have to store
+	; its value in the lower half of rdi.
+	; this ensures that the upper half is
+	; zeroed as well.
+
+	mov edi, [rsp + 0] ; sizeof arguments
+	; first argument to _boot(): argc
+	; this is a 32-bit signed(??) integer
+	; that is equal to the number of
+	; elements in argv (see below). it is
+	; not strictly necessary, because argv
+	; is per spec always null-terminated,
+	; but we pass it just in case.
+
+	lea rsi, [rsp + 8] ; &arguments
+	; 2nd argument to _boot(): ptr to argv
+	; this points to an array of strings
+	; containing the program's command line
+	; arguments. _boot() does not need to 
+	; parse this, but it does need to store
+	; it in the structure passed to main()
+
+	lea rdx, [rsp + 16] ; &environment
+	; third argument to _boot(): ptr to envp
+	; this points to the list of environment
+	; variables for the running program. it
+	; is the responsibility of _boot to parse
+	; this list and arrange it into a set of
+	; legible and useful C arrays.
+
+	mov rax, 0 ; zero out %rax
+	; this is required by the C ABI, and is
+	; reputedly necessary for compatibility
+	; with icc, intel's own proprietary C
+	; compiler.
+
+	call _boot ; invoke the start function
+	; that will set up the runtime and
+	; construct the necessary structures
+	; that will be bassed to libc.
+
+	; boot has returned and left its
+	; return value in the register %rax.
+	; regardless of the size of the
+	; return value of main(), _boot always
+	; returns the system word length.
+
+	mov sys.reg.1, sys.reg.ret ; fill in
+	; the return value as exit's argument
 
-	call _boot
+	mov sys.reg.0, sys.exit ; set %rax to
+	; the syscall number of exit
 
-	mov sys.reg.1, sys.reg.ret
-	mov sys.reg.0, sys.exit
-	sys.call
+	sys.call ; invoke the kernel