diff --git a/sys/bootstrap/CMakeLists.txt b/sys/bootstrap/CMakeLists.txt
index 5381979..8e3b73e 100644
--- a/sys/bootstrap/CMakeLists.txt
+++ b/sys/bootstrap/CMakeLists.txt
@@ -5,7 +5,7 @@ set_property(SOURCE ${arch_sources} PROPERTY LANGUAGE C)
 
 add_executable(bootstrap ${c_sources} ${arch_sources})
 
-target_link_libraries(bootstrap libmango ulibc liblaunch libmsg-fs)
+target_link_libraries(bootstrap libmango ulibc liblaunch interface::fs)
 
 target_compile_options(bootstrap PRIVATE
 	-fPIC -pie -fno-stack-protector -nostdlib -ffreestanding)
diff --git a/sys/bootstrap/arch/x86_64/start.S b/sys/bootstrap/arch/x86_64/start.S
index 45ef52b..f600396 100644
--- a/sys/bootstrap/arch/x86_64/start.S
+++ b/sys/bootstrap/arch/x86_64/start.S
@@ -6,10 +6,12 @@
 .extern main
 .type main, @function
 
-.extern exit
-.type exit, @function
+.extern task_exit
+.type task_exit, @function
 
 _start:
 	call main
+	mov %rax, %rdi
+	call task_exit
 1:	pause
 	jmp 1b
diff --git a/sys/bootstrap/main.c b/sys/bootstrap/main.c
index 56960e1..751c5ed 100644
--- a/sys/bootstrap/main.c
+++ b/sys/bootstrap/main.c
@@ -1,3 +1,5 @@
+#define MSG_IMPLEMENTATION
+#define MSG_NO_MALLOC
 #include "tar.h"
 
 #include <launch.h>
@@ -5,8 +7,7 @@
 #include <mango/msg.h>
 #include <mango/task.h>
 #include <mango/types.h>
-#include <rosetta/msg.h>
-#include <rosetta/msg/fs.h>
+#include <rosetta/fs.h>
 #include <stdint.h>
 #include <stdio.h>
 
@@ -46,6 +47,31 @@ static enum launch_status resolve_dependency(
 	return LAUNCH_OK;
 }
 
+static kern_status_t open(const char *path, int flags, int *out_err)
+{
+	kern_logf("received msg: open(%s, %d)", path, flags);
+	*out_err = 13;
+	return KERN_OK;
+}
+
+static kern_status_t uppercase(const char *old, struct msg_string *new)
+{
+	kern_logf("received msg: uppercase(%s)", old);
+	size_t i;
+	for (i = 0; old[i] && i < new->str_max - 1; i++) {
+		char c = old[i];
+		if (c >= 'a' && c <= 'z') {
+			new->str_buf[i] = old[i] - 'a' + 'A';
+		} else {
+			new->str_buf[i] = old[i];
+		}
+	}
+
+	new->str_len = i - 1;
+	new->str_buf[i] = 0;
+	return KERN_OK;
+}
+
 int main(
 	int argc,
 	const char **argv,
@@ -98,48 +124,29 @@ int main(
 		= launch_ctx_execute(&launch, &params, LAUNCH_F_NONE, &result);
 	kern_logf("launch result: %d", status);
 
+	const struct fs_vtable fs_vtable = {
+		.open = open,
+		.uppercase = uppercase,
+	};
 #if 1
 
 	while (1) {
 		msgid_t id;
-		struct rosetta_msg msg;
-		kern_status_t status = rosetta_msg_recv(channel, &id, &msg);
+		struct msg_header hdr;
+		kern_status_t status = msg_recv_generic(channel, &id, &hdr);
 		if (status != KERN_OK) {
 			kern_logf("message recv error %d", status);
 			continue;
 		}
 
-		if (msg.msg_protocol != ROSETTA_MSG_FS) {
+		if (hdr.hdr_protocol != PROTOCOL_FS) {
 			kern_logf(
 				"unknown message protocol %u",
-				msg.msg_protocol);
+				hdr.hdr_protocol);
 			continue;
 		}
 
-		if (msg.msg_id != ROSETTA_MSG_FS_OPEN) {
-			kern_logf("unknown message function %u", msg.msg_id);
-			continue;
-		}
-
-		char path[4096];
-		int flags;
-		struct rosetta_msg_string path_str = {
-			.s_buf = path,
-			.s_max = sizeof path,
-		};
-		status = rosetta_msg_fs_open_recv(
-			channel,
-			id,
-			&path_str,
-			&flags);
-		if (status != KERN_OK) {
-			kern_logf("rosetta.fs.open recv error %d", status);
-			continue;
-		}
-
-		kern_logf("open(%s, %d)", path, flags);
-
-		rosetta_msg_fs_open_reply(channel, id, 0);
+		status = fs_dispatch(channel, &fs_vtable, id, &hdr);
 	}
 #endif