test: boot: add a fdt reserved region check

Add a image_fdt suite and a check for boot_fdt_add_mem_rsv_regions. This
will ensure the user is properly informed of any reservation failures.
It will also validate that reservations are cleaned up correctly when
switching FDTs.

Signed-off-by: Randolph Sapp <rs@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

test/boot/Makefile

@@ -14,6 +14,9 @@ endif
 
 ifdef CONFIG_SANDBOX
 obj-$(CONFIG_$(PHASE_)CMDLINE) += bootm.o
+ifdef CONFIG_UT_DM
+obj-$(CONFIG_$(PHASE_)OF_LIBFDT) += image_fdt.o
+endif
 endif
 obj-$(CONFIG_MEASURED_BOOT) += measurement.o
 

test/boot/image_fdt.c

@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2026 Texas Instruments Incorporated - https://www.ti.com/
+ */
+
+#include <config.h>
+
+#include <fdt_support.h>
+#include <image.h>
+#include <lmb.h>
+#include <malloc.h>
+
+#include <asm/global_data.h>
+
+#include <test/test.h>
+#include <test/ut.h>
+
+#define IMAGE_FDT_TEST(_name, _flags) UNIT_TEST(_name, _flags, image_fdt)
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/**
+ * test_boot_fdt_add_mem_rsv_regions - Make sure dt reservations are created and
+ *                                     destroyed correctly
+ * @uts: Test state
+ *
+ * This test depends on the UT_DM device tree and ensures the following
+ * statements hold true: The default reservation in test.dtb exists.
+ * Re-reserving that region will result in an error. Loading a new device tree
+ * will remove old reservations.
+ */
+static int test_boot_fdt_add_mem_rsv_regions(struct unit_test_state *uts)
+{
+	phys_addr_t start = CFG_SYS_SDRAM_BASE + 0x100000;
+	const void *old_blob = gd->fdt_blob;
+	int ret = CMD_RET_FAILURE;
+	ulong fdt_sz;
+	int nodeoffset;
+	void *new_blob;
+
+	/* Default reservation should exist */
+	ut_asserteq(1, lmb_is_reserved_flags(start, LMB_NOMAP));
+
+	/* Attempting to re-reserve should warn the user */
+	boot_fdt_add_mem_rsv_regions(gd->fdt_blob);
+	ut_assert_nextlinen("ERROR: reserving");
+	ut_assert_console_end();
+
+	/* Loading a new_blob device tree should be allowed */
+	fdt_sz = fdt_totalsize(gd->fdt_blob);
+	new_blob = malloc(fdt_sz);
+	ut_assertnonnull(new_blob);
+	memcpy(new_blob, gd->fdt_blob, fdt_sz);
+
+	nodeoffset = fdt_path_offset(new_blob, "/reserved-memory");
+	if (nodeoffset < 0)
+		goto free_blob;
+
+	if (fdt_del_node(new_blob, nodeoffset))
+		goto free_blob;
+
+	boot_fdt_add_mem_rsv_regions(new_blob);
+	gd->fdt_blob = new_blob;
+
+	if (ut_check_console_end(uts)) {
+		ut_failf(uts, __FILE__, __LINE__, __func__, "console",
+			 "Expected no more output, got '%s'", uts->actual_str);
+		goto switch_fdt;
+	}
+
+	/* Reservation should not exist now */
+	if (!lmb_is_reserved_flags(start, LMB_NOMAP))
+		ret = 0;
+
+	/* Cleanup */
+switch_fdt:
+	boot_fdt_add_mem_rsv_regions(old_blob);
+	gd->fdt_blob = old_blob;
+free_blob:
+	free(new_blob);
+	return ret;
+}
+IMAGE_FDT_TEST(test_boot_fdt_add_mem_rsv_regions, UTF_CONSOLE);

test/cmd_ut.c

@@ -61,6 +61,7 @@ SUITE_DECL(fdt);
 SUITE_DECL(fdt_overlay);
 SUITE_DECL(font);
 SUITE_DECL(hush);
+SUITE_DECL(image_fdt);
 SUITE_DECL(lib);
 SUITE_DECL(loadm);
 SUITE_DECL(log);
@@ -88,6 +89,7 @@ static struct suite suites[] = {
 	SUITE(fdt_overlay, "device tree overlays"),
 	SUITE(font, "font command"),
 	SUITE(hush, "hush behaviour"),
+	SUITE(image_fdt, "image fdt parsing"),
 	SUITE(lib, "library functions"),
 	SUITE(loadm, "loadm command parameters and loading memory blob"),
 	SUITE(log, "logging functions"),

test/py/tests/test_suite.py

@@ -8,7 +8,7 @@ import re
 EXPECTED_SUITES = [
     'addrmap', 'bdinfo', 'bloblist', 'bootm', 'bootstd',
     'cmd', 'common', 'dm', 'env', 'exit', 'fdt_overlay',
-    'fdt', 'font', 'hush', 'lib',
+    'fdt', 'font', 'hush', 'image_fdt', 'lib',
     'loadm', 'log', 'mbr', 'measurement', 'mem',
     'pci_mps', 'setexpr', 'upl',
     ]