os

commit cc8fe1a7405f48e3ca08f6559c01b4b305cc7db5
parent 43548acf4c60f144ed9892d9e8a6ff105de197de
Author: erai <erai@omiltem.net>
Date:   Sat, 30 Mar 2024 11:21:00 -0400

ud2 at end of _start

Diffstat:
M
as.c
 | 
5
+++++
M
cc0.c
 | 
6
++++++
M
cc1.c
 | 
5
+++++
M
kernel.c
 | 
1
-

4 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/as.c b/as.c
@@ -63,6 +63,7 @@ enum {
 	OP_HLT = 0xf4,
 	OP_NOP = 0x90,
 	OP_WBINVD = 0x0f09,
+	OP_UD2 = 0x0f0b,
 
 	OP_INVLPGM = 0x070f01,
 	OP_LLDM = 0x020f00,
@@ -606,6 +607,10 @@ emit_add(c: *assembler) {
 	as_opr(c, OP_PUSHR, R_RAX);
 }
 
+emit_ud(c: *assembler) {
+	as_op(c, OP_UD2);
+}
+
 emit_ret(c: *assembler) {
 	as_opr(c, OP_POPR, R_RAX);
 	as_modrr(c, OP_MOVE, R_RSP, R_RBP);
diff --git a/cc0.c b/cc0.c
@@ -4918,6 +4918,12 @@ tfunc(struct decl *d)
 	tstmt(d->body);
 
 	emit_num(0);
+
+	if (!cmp(d->name, (unsigned char *)"_start")) {
+		emit(0x0f);
+		emit(0x0b);
+	}
+
 	emit_ret();
 }
 
diff --git a/cc1.c b/cc1.c
@@ -350,6 +350,11 @@ compile_func(c: *compiler, d: *decl) {
 	emit_preamble(c.as, offset, pragma);
 	compile_stmt(c, d, d.func_def.b, 0:*label, 0:*label);
 	emit_num(c.as, 0);
+
+	if (pragma) {
+		emit_ud(c.as);
+	}
+
 	emit_ret(c.as);
 }
 
diff --git a/kernel.c b/kernel.c
@@ -1,7 +1,6 @@
 // in out iretq rdmsr wrmsr wrcr rdcr lgdt lldt lidt ltr hlt cli sti syscall sysret wbinvld invlpg
 
 _start() {
-	loop { }
 }
 
 ru32(p: *byte): int {