sys: add userspace bootstrap program

sys/bootstrap/main.c

@@ -0,0 +1,99 @@
+#include "tar.h"
+
+#include <launch.h>
+#include <mango/log.h>
+#include <mango/msg.h>
+#include <mango/task.h>
+#include <mango/types.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+#define INIT_PATH "/usr/bin/test"
+
+static enum launch_status resolve_dependency(
+	struct launch_ctx *ctx,
+	const char *name,
+	kern_handle_t *out,
+	void *arg)
+{
+	char s[128];
+	while (*name == '/') {
+		name++;
+	}
+
+	snprintf(s, sizeof s, "searching for library %s", name);
+	kern_log(s);
+
+	struct tar *fs = arg;
+	struct tar_file file = {0};
+	if (tar_open(fs, name, &file) != 0) {
+		snprintf(s, sizeof s, "cannot find library %s", name);
+		kern_log(s);
+		return LAUNCH_ERR_CANNOT_RESOLVE_DEPENDENCY;
+	}
+
+	kern_handle_t image = KERN_HANDLE_INVALID;
+	int err = tar_file_create_vm_object(&file, &image);
+	if (err != 0) {
+		snprintf(s, sizeof s, "cannot load library %s", name);
+		kern_log(s);
+		return -1;
+	}
+
+	*out = image;
+	return LAUNCH_OK;
+}
+
+int main(
+	int argc,
+	const char **argv,
+	kern_handle_t task,
+	kern_handle_t address_space,
+	uintptr_t bsp_base)
+{
+	struct tar bsp = {0};
+	if (tar_init(&bsp, bsp_base) != 0) {
+		kern_log("cannot access bsp");
+		return -1;
+	}
+
+	struct tar_file init = {0};
+	if (tar_open(&bsp, INIT_PATH, &init) != 0) {
+		kern_log("cannot find init program " INIT_PATH);
+		return -1;
+	}
+
+	kern_trace("loading " INIT_PATH);
+
+	kern_handle_t image = KERN_HANDLE_INVALID;
+	int err = tar_file_create_vm_object(&init, &image);
+	if (err != 0) {
+		kern_log("cannot load executable " INIT_PATH);
+		return -1;
+	}
+
+	kern_trace("loaded executable vm-object " INIT_PATH);
+
+	kern_tracef("task=%x, region=%x", task, address_space);
+
+	struct launch_ctx launch;
+	struct launch_result result;
+	struct launch_parameters params = {
+		.p_executable = image,
+		.p_parent_task = task,
+		.p_task_name = "init",
+		.p_local_address_space = address_space,
+		.p_resolver_arg = &bsp,
+	};
+
+	launch_ctx_init(&launch);
+	launch.ctx_resolve_library = resolve_dependency;
+
+	enum launch_status status
+		= launch_ctx_execute(&launch, &params, LAUNCH_F_NONE, &result);
+
+	kern_tracef("launch result: %d", status);
+
+	return 102;
+}