sandbox: implement reset

Up to now the sandbox would shutdown upon a cold reset request. Instead it
should be reset.

In our coding we use static variables like LIST_HEAD(efi_obj_list). A reset
can occur at any time, e.g. via an UEFI binary calling the reset service.
The only safe way to return to an initial state is to relaunch the U-Boot
binary.

The reset implementation uses execv() to relaunch U-Boot.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 26 insertions, 0 deletions

diff --git a/arch/sandbox/cpu/start.c b/arch/sandbox/cpu/start.c
index 58ada13fba5..a03e5aa0b30 100644
--- a/arch/sandbox/cpu/start.c
+++ b/arch/sandbox/cpu/start.c
@@ -5,6 +5,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <dm/root.h>
 #include <errno.h>
 #include <init.h>
 #include <os.h>
@@ -19,6 +20,8 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+static char **os_argv;
+
 /* Compare two options so that they can be sorted into alphabetical order */
 static int h_compare_opt(const void *p1, const void *p2)
 {
@@ -403,12 +406,35 @@ void state_show(struct sandbox_state *state)
 	printf("\n");
 }
 
+void sandbox_reset(void)
+{
+	/* Do this here while it still has an effect */
+	os_fd_restore();
+	if (state_uninit())
+		os_exit(2);
+
+	if (dm_uninit())
+		os_exit(2);
+
+	/* Restart U-Boot */
+	os_relaunch(os_argv);
+}
+
 int main(int argc, char *argv[])
 {
 	struct sandbox_state *state;
 	gd_t data;
 	int ret;
 
+	/*
+	 * Copy argv[] so that we can pass the arguments in the original
+	 * sequence when resetting the sandbox.
+	 */
+	os_argv = calloc(argc + 1, sizeof(char *));
+	if (!os_argv)
+		os_exit(1);
+	memcpy(os_argv, argv, sizeof(char *) * (argc + 1));
+
 	memset(&data, '\0', sizeof(data));
 	gd = &data;
 	gd->arch.text_base = os_find_text_base();