sandbox: Add a -N flag to control on-host behaviour

Sandbox is its own architecture, but sometimes we want to mimic the host
architecture, e.g. when running an EFI app not built by U-Boot.

Add a -N/--native flag which tells sandbox to reflect the architecture
of the host.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/sandbox/cpu/start.c b/arch/sandbox/cpu/start.c
index 81752ed..2940768 100644
--- a/arch/sandbox/cpu/start.c
+++ b/arch/sandbox/cpu/start.c
@@ -449,6 +449,16 @@
 	gd->ram_size = state->ram_size;
 }
 
+static int sandbox_cmdline_cb_native(struct sandbox_state *state,
+				     const char *arg)
+{
+	state->native = true;
+
+	return 0;
+}
+SANDBOX_CMDLINE_OPT_SHORT(native, 'N', 0,
+			  "Use native mode (host-based EFI boot filename)");
+
 void state_show(struct sandbox_state *state)
 {
 	char **p;
diff --git a/arch/sandbox/include/asm/state.h b/arch/sandbox/include/asm/state.h
index e7dc017..dc21a62 100644
--- a/arch/sandbox/include/asm/state.h
+++ b/arch/sandbox/include/asm/state.h
@@ -101,6 +101,7 @@
 	bool disable_eth;		/* Disable Ethernet devices */
 	bool disable_sf_bootdevs;	/* Don't bind SPI flash bootdevs */
 	bool upl;			/* Enable Universal Payload (UPL) */
+	bool native;			/* Adjust to reflect host arch */
 
 	/* Pointer to information for each SPI bus/cs */
 	struct sandbox_spi_info spi[CONFIG_SANDBOX_SPI_MAX_BUS]