cmd: mbr: Allow 4 MBR partitions without need for extended

Current code allows up to 3 MBR partitions without extended one.
If more than 3 partitions are required, then extended partition(s)
must be used.
This commit allows up to 4 primary MBR partitions without the
need for extended partition.

Add mbr test unit. In order to run the test manually, mmc6.img file
of size 12 MiB or greater is required in the same directory as u-boot.
Test also runs automatically via ./test/py/test.py tool.
Running mbr test is only supported in sandbox mode.

Signed-off-by: Alex Gendin <agendin@matrox.com>
[ And due to some further changes for testing ]
Signed-off-by: Simon Glass <sjg@chromium.org>

10 files changed, 506 insertions, 4 deletions

diff --git a/arch/Kconfig b/arch/Kconfig
index 19f2891..4f5b751 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -208,6 +208,8 @@ config SANDBOX
 	imply PHYSMEM
 	imply GENERATE_ACPI_TABLE
 	imply BINMAN
+	imply CMD_MBR
+	imply CMD_MMC
 
 config SH
 	bool "SuperH architecture"
diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index e430347..577ef34 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -41,6 +41,7 @@
 		mmc3 = "/mmc3";
 		mmc4 = "/mmc4";
 		mmc5 = "/mmc5";
+		mmc6 = "/mmc6";
 		pci0 = &pci0;
 		pci1 = &pci1;
 		pci2 = &pci2;
@@ -1102,6 +1103,13 @@
 		filename = "mmc5.img";
 	};
 
+	/* This is used for mbr tests */
+	mmc6 {
+		status = "disabled";
+		compatible = "sandbox,mmc";
+		filename = "mmc6.img";
+	};
+
 	pch {
 		compatible = "sandbox,pch";
 	};
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index 03475a5..96cd701 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -73,8 +73,6 @@ CONFIG_CMD_IDE=y
 CONFIG_CMD_I2C=y
 CONFIG_CMD_LOADM=y
 CONFIG_CMD_LSBLK=y
-CONFIG_CMD_MBR=y
-CONFIG_CMD_MMC=y
 CONFIG_CMD_MUX=y
 CONFIG_CMD_OSD=y
 CONFIG_CMD_PCI=y
diff --git a/configs/sandbox_flattree_defconfig b/configs/sandbox_flattree_defconfig
index 29ae453..44ab807 100644
--- a/configs/sandbox_flattree_defconfig
+++ b/configs/sandbox_flattree_defconfig
@@ -47,10 +47,12 @@ CONFIG_CMD_MBR=y
 CONFIG_CMD_MMC=y
 CONFIG_CMD_OSD=y
 CONFIG_CMD_PCI=y
+CONFIG_CMD_READ=y
 CONFIG_CMD_REMOTEPROC=y
 CONFIG_CMD_SPI=y
 CONFIG_CMD_TEMPERATURE=y
 CONFIG_CMD_USB=y
+CONFIG_CMD_WRITE=y
 CONFIG_BOOTP_DNS2=y
 CONFIG_CMD_TFTPPUT=y
 CONFIG_CMD_TFTPSRV=y
diff --git a/disk/part_dos.c b/disk/part_dos.c
index 3337438..567ead7 100644
--- a/disk/part_dos.c
+++ b/disk/part_dos.c
@@ -466,7 +466,7 @@ int layout_mbr_partitions(struct disk_partition *p, int count,
 			ext = &p[i];
 	}
 
-	if (count < 4)
+	if (count <= 4)
 		return 0;
 
 	if (!ext) {
diff --git a/include/test/suites.h b/include/test/suites.h
index 1c7dc65..51acbe4 100644
--- a/include/test/suites.h
+++ b/include/test/suites.h
@@ -45,6 +45,7 @@ int do_ut_font(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
 int do_ut_lib(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
 int do_ut_loadm(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
 int do_ut_log(struct cmd_tbl *cmdtp, int flag, int argc, char * const argv[]);
+int do_ut_mbr(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
 int do_ut_mem(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
 int do_ut_optee(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
 int do_ut_overlay(struct cmd_tbl *cmdtp, int flag, int argc,
diff --git a/test/cmd/Makefile b/test/cmd/Makefile
index 8d70ac5..e296ba1 100644
--- a/test/cmd/Makefile
+++ b/test/cmd/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_CMD_PINMUX) += pinmux.o
 obj-$(CONFIG_CMD_PWM) += pwm.o
 obj-$(CONFIG_CMD_SEAMA) += seama.o
 ifdef CONFIG_SANDBOX
+obj-$(CONFIG_CMD_MBR) += mbr.o
 obj-$(CONFIG_CMD_READ) += rw.o
 obj-$(CONFIG_CMD_SETEXPR) += setexpr.o
 obj-$(CONFIG_ARM_FFA_TRANSPORT) += armffa.o
diff --git a/test/cmd/mbr.c b/test/cmd/mbr.c
new file mode 100644
index 0000000..5d74021
--- /dev/null
+++ b/test/cmd/mbr.c
@@ -0,0 +1,481 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Tests for mbr command
+ *
+ * Copyright 2023 Matrox Video
+ * Written by Alex Gendin <agendin@matrox.com>
+ */
+
+#include <dm.h>
+#include <console.h>
+#include <dm/test.h>
+#include <mapmem.h>
+#include <part.h>
+#include <asm/global_data.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <test/suites.h>
+#include <test/ut.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+/*
+ * Requirements for running test manually:
+ * mmc6.img - File size needs to be at least 12 MiB
+ *
+ * Command to create mmc6.img:
+ * $ dd if=/dev/zero of=mmc6.img bs=12M count=1
+ *
+ * To run this test manually, place mmc6.img into the same directory as u-boot,
+ * then run:
+ * $ ./u-boot -Tc 'ut mbr'
+ *
+ * To run this test as part of U-Boot test:
+ * $ ./test/py/test.py --bd sandbox --build -k ut_dm -v
+ * Note: mmc6.img will be created by the test suit.
+ */
+
+static char * mbr_parts_header = "setenv mbr_parts '";
+static char * mbr_parts_p1 = "uuid_disk=0x12345678;name=p1,start=8M,bootable,size=1M,id=0x0e";
+static char * mbr_parts_p2 = ";name=p2,size=1M,id=0x0e";
+static char * mbr_parts_p3 = ";name=p3,size=1M,id=0x0e";
+static char * mbr_parts_p4 = ";name=p4,size=1M,id=0x0e";
+static char * mbr_parts_p5 = ";name=[ext],size=2M,id=0x05;name=p5,size=1M,id=0x0e";
+static char * mbr_parts_tail = "'";
+
+/*
+ * One MBR partition
+000001b0  00 00 00 00 00 00 00 00  78 56 34 12 00 00 80 05  |........xV4.....|
+000001c0  05 01 0e 25 24 01 00 40  00 00 00 08 00 00 00 00  |...%$..@........|
+000001d0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
+000001e0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
+000001f0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 55 aa  |..............U.|
+*/
+static unsigned mbr_cmp_start = 0x1B8;
+static unsigned mbr_cmp_size = 0x48;
+static unsigned char mbr_parts_ref_p1[] = {
+                                                0x78, 0x56, 0x34, 0x12, 0x00, 0x00, 0x80, 0x05,
+0x05, 0x01, 0x0e, 0x25, 0x24, 0x01, 0x00, 0x40, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00,
+0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x55, 0xaa
+};
+
+/*
+ * Two MBR partitions
+000001b0  00 00 00 00 00 00 00 00  78 56 34 12 00 00 80 05  |........xV4.....|
+000001c0  05 01 0e 25 24 01 00 40  00 00 00 08 00 00 00 25  |...%$..@.......%|
+000001d0  25 01 0e 46 05 01 00 48  00 00 00 08 00 00 00 00  |%..F...H........|
+000001e0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
+000001f0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 55 aa  |..............U.|
+*/
+static unsigned char mbr_parts_ref_p2[] = {
+                                                0x78, 0x56, 0x34, 0x12, 0x00, 0x00, 0x80, 0x05,
+0x05, 0x01, 0x0e, 0x25, 0x24, 0x01, 0x00, 0x40, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x25,
+0x25, 0x01, 0x0e, 0x46, 0x05, 0x01, 0x00, 0x48, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00,
+0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x55, 0xaa
+};
+
+/*
+ * Three MBR partitions
+000001b0  00 00 00 00 00 00 00 00  78 56 34 12 00 00 80 05  |........xV4.....|
+000001c0  05 01 0e 25 24 01 00 40  00 00 00 08 00 00 00 25  |...%$..@.......%|
+000001d0  25 01 0e 46 05 01 00 48  00 00 00 08 00 00 00 46  |%..F...H.......F|
+000001e0  06 01 0e 66 25 01 00 50  00 00 00 08 00 00 00 00  |...f%..P........|
+000001f0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 55 aa  |..............U.|
+*/
+static unsigned char mbr_parts_ref_p3[] = {
+                                                0x78, 0x56, 0x34, 0x12, 0x00, 0x00, 0x80, 0x05,
+0x05, 0x01, 0x0e, 0x25, 0x24, 0x01, 0x00, 0x40, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x25,
+0x25, 0x01, 0x0e, 0x46, 0x05, 0x01, 0x00, 0x48, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x46,
+0x06, 0x01, 0x0e, 0x66, 0x25, 0x01, 0x00, 0x50, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00,
+0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x55, 0xaa
+};
+
+/*
+ * Four MBR partitions
+000001b0  00 00 00 00 00 00 00 00  78 56 34 12 00 00 80 05  |........xV4.....|
+000001c0  05 01 0e 25 24 01 00 40  00 00 00 08 00 00 00 25  |...%$..@.......%|
+000001d0  25 01 0e 46 05 01 00 48  00 00 00 08 00 00 00 46  |%..F...H.......F|
+000001e0  06 01 0e 66 25 01 00 50  00 00 00 08 00 00 00 66  |...f%..P.......f|
+000001f0  26 01 0e 87 06 01 00 58  00 00 00 08 00 00 55 aa  |&......X......U.|
+*/
+static unsigned char mbr_parts_ref_p4[] = {
+                                                0x78, 0x56, 0x34, 0x12, 0x00, 0x00, 0x80, 0x05,
+0x05, 0x01, 0x0e, 0x25, 0x24, 0x01, 0x00, 0x40, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x25,
+0x25, 0x01, 0x0e, 0x46, 0x05, 0x01, 0x00, 0x48, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x46,
+0x06, 0x01, 0x0e, 0x66, 0x25, 0x01, 0x00, 0x50, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x66,
+0x26, 0x01, 0x0e, 0x87, 0x06, 0x01, 0x00, 0x58, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x55, 0xaa
+};
+
+/*
+ * Five MBR partitions
+000001b0  00 00 00 00 00 00 00 00  78 56 34 12 00 00 80 05  |........xV4.....|
+000001c0  05 01 0e 25 24 01 00 40  00 00 00 08 00 00 00 25  |...%$..@.......%|
+000001d0  25 01 0e 46 05 01 00 48  00 00 00 08 00 00 00 46  |%..F...H.......F|
+000001e0  06 01 0e 66 25 01 00 50  00 00 00 08 00 00 00 66  |...f%..P.......f|
+000001f0  26 01 05 a7 26 01 00 58  00 00 00 10 00 00 55 aa  |&...&..X......U.|
+*/
+static unsigned char mbr_parts_ref_p5[] = {
+                                                0x78, 0x56, 0x34, 0x12, 0x00, 0x00, 0x80, 0x05,
+0x05, 0x01, 0x0e, 0x25, 0x24, 0x01, 0x00, 0x40, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x25,
+0x25, 0x01, 0x0e, 0x46, 0x05, 0x01, 0x00, 0x48, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x46,
+0x06, 0x01, 0x0e, 0x66, 0x25, 0x01, 0x00, 0x50, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x66,
+0x26, 0x01, 0x05, 0xa7, 0x26, 0x01, 0x00, 0x58, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x55, 0xaa
+};
+static unsigned ebr_cmp_start = 0x1B8;
+static unsigned ebr_cmp_size = 0x48;
+/*
+ * EBR
+00b001b0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 87  |................|
+00b001c0  07 01 0e a7 26 01 00 08  00 00 00 08 00 00 00 00  |....&...........|
+00b001d0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
+00b001e0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
+00b001f0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 55 aa  |..............U.|
+*/
+static unsigned char ebr_parts_ref_p5[] = {
+                                                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x87,
+0x07, 0x01, 0x0e, 0xa7, 0x26, 0x01, 0x00, 0x08, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00,
+0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x55, 0xaa
+};
+
+/* Fill write buffers with pseudo-random data */
+static void init_write_buffers(char *mbr_wb, size_t mbr_wb_size,
+			char *ebr_wb, size_t ebr_wb_size, unsigned seed)
+{
+	while (mbr_wb_size--) {
+		*mbr_wb++ = seed;
+		seed *= 43;
+		seed += 17 + mbr_wb_size/4;
+	}
+	while (ebr_wb_size--) {
+		*ebr_wb++ = seed;
+		seed *= 43;
+		seed += 17 + ebr_wb_size/4;
+	}
+}
+
+/* Build string with MBR partition(s) layout */
+static unsigned build_mbr_parts(char *buf, size_t buf_size, unsigned num_parts)
+{
+	size_t bytes_remaining, cur_str_size;
+	char * cur_buf;
+
+	if (!num_parts || num_parts > 5 || !buf)
+		return 1;
+
+	cur_buf = buf;
+	*cur_buf = '\0';
+	bytes_remaining = buf_size;
+
+	cur_str_size = sizeof(mbr_parts_header);
+	if (cur_str_size + 1 > bytes_remaining)
+		return 1;
+	strcat(cur_buf, mbr_parts_header);
+	bytes_remaining -= cur_str_size;
+
+	if (num_parts >= 1) {
+		cur_str_size = sizeof(mbr_parts_p1);
+		if (cur_str_size + 1 > bytes_remaining)
+			return 1;
+		strcat(cur_buf, mbr_parts_p1);
+		bytes_remaining -= cur_str_size;
+
+		if (num_parts >= 2) {
+			cur_str_size = sizeof(mbr_parts_p2);
+			if (cur_str_size + 1 > bytes_remaining)
+				return 1;
+			strcat(cur_buf, mbr_parts_p2);
+			bytes_remaining -= cur_str_size;
+
+			if (num_parts >= 3) {
+				cur_str_size = sizeof(mbr_parts_p3);
+				if (cur_str_size + 1 > bytes_remaining)
+					return 1;
+				strcat(cur_buf, mbr_parts_p3);
+				bytes_remaining -= cur_str_size;
+
+				if (num_parts == 4) {
+					cur_str_size = sizeof(mbr_parts_p4);
+					if (cur_str_size + 1 > bytes_remaining)
+						return 1;
+					strcat(cur_buf, mbr_parts_p4);
+					bytes_remaining -= cur_str_size;
+
+				}
+			else if (num_parts == 5) {
+				cur_str_size = sizeof(mbr_parts_p5);
+				if (cur_str_size + 1 > bytes_remaining)
+					return 1;
+				strcat(cur_buf, mbr_parts_p5);
+				bytes_remaining -= cur_str_size;
+
+			}
+			else if (num_parts > 5)
+				return 1;
+			}
+		}
+	}
+
+	cur_str_size = sizeof(mbr_parts_tail);
+	if (cur_str_size + 1 > bytes_remaining)
+		return 1;
+	strcat(cur_buf, mbr_parts_tail);
+
+	return 0;
+}
+
+static int mbr_test_run(struct unit_test_state *uts)
+{
+	struct blk_desc *mmc_dev_desc;
+	unsigned char mbr_wbuf[512], ebr_wbuf[512], rbuf[512];
+	char mbr_parts_buf[256];
+	ulong mbr_wa, ebr_wa, ra, ebr_blk, mbr_parts_max;
+	struct udevice *dev;
+	ofnode root, node;
+
+	/* Enable the mmc6 node for this test */
+	root = oftree_root(oftree_default());
+	node = ofnode_find_subnode(root, "mmc6");
+	ut_assert(ofnode_valid(node));
+	ut_assertok(lists_bind_fdt(gd->dm_root, node, &dev, NULL, false));
+
+	mbr_parts_max = sizeof('\0') + 2 +
+		strlen(mbr_parts_header) +
+		strlen(mbr_parts_p1) +
+		strlen(mbr_parts_p2) +
+		strlen(mbr_parts_p3) +
+		max(strlen(mbr_parts_p4), strlen(mbr_parts_p5)) +
+		strlen(mbr_parts_tail);
+	ut_assertf(sizeof(mbr_parts_buf) >= mbr_parts_max, "Buffer avail: %ld; buffer req: %ld\n",
+		sizeof(mbr_parts_buf), mbr_parts_max);
+
+	mbr_wa = map_to_sysmem(mbr_wbuf);
+	ebr_wa = map_to_sysmem(ebr_wbuf);
+	ra = map_to_sysmem(rbuf);
+	ebr_blk = (ulong)0xB00000 / 0x200;
+
+	/* Make sure mmc6 exists */
+	ut_asserteq(6, blk_get_device_by_str("mmc", "6", &mmc_dev_desc));
+	ut_assertok(console_record_reset_enable());
+	ut_assertok(run_commandf("mmc dev 6"));
+	ut_assert_nextline("switch to partitions #0, OK");
+	ut_assert_nextline("mmc6 is current device");
+	ut_assertok(ut_check_console_end(uts));
+
+	/* Make sure mmc6 is 12+ MiB in size */
+	ut_assertok(run_commandf("mmc read 0x%lx 0x%lx 1", ra, (ulong)0xBFFE00 / 0x200));
+
+	/* Test one MBR partition */
+	init_write_buffers(mbr_wbuf, sizeof(mbr_wbuf), ebr_wbuf, sizeof(ebr_wbuf), __LINE__);
+	ut_assertok(build_mbr_parts(mbr_parts_buf, sizeof(mbr_parts_buf), 1));
+	ut_assertok(run_commandf("write mmc 6:0 0x%lx 0 1", mbr_wa));
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0 1", ra));
+	ut_assertok(memcmp(mbr_wbuf, rbuf, 512));
+	ut_assertok(run_commandf("write mmc 6:0 0x%lx 0x%lx 1", ebr_wa, ebr_blk));
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0x%lx 1", ra, ebr_blk));
+	ut_assertok(memcmp(ebr_wbuf, rbuf, 512));
+	ut_assertok(console_record_reset_enable());
+	ut_assertf(0 == run_commandf(mbr_parts_buf), "Invalid partitions string: %s\n", mbr_parts_buf);
+	ut_assertok(run_commandf("mbr write mmc 6"));
+	ut_assert_nextline("MBR: write success!");
+	ut_assertok(run_commandf("mbr verify mmc 6"));
+	ut_assert_nextline("MBR: verify success!");
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0x%lx 1", ra, ebr_blk));
+	ut_assertok(memcmp(ebr_wbuf, rbuf, 512));
+	ut_assertok(ut_check_console_end(uts));
+	/*
+	000001b0  00 00 00 00 00 00 00 00  78 56 34 12 00 00 80 05  |........xV4.....|
+	000001c0  05 01 0e 25 24 01 00 40  00 00 00 08 00 00 00 00  |...%$..@........|
+	000001d0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
+	000001e0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
+	000001f0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 55 aa  |..............U.|
+	*/
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0 1", ra));
+	for (unsigned i = 0; i < mbr_cmp_size; i++) {
+		ut_assertf(rbuf[mbr_cmp_start + i] == mbr_parts_ref_p1[i],
+			"1P MBR+0x%04X: expected 0x%02X, actual: 0x%02X\n",
+			mbr_cmp_start + i, mbr_parts_ref_p1[i], rbuf[mbr_cmp_start + i]);
+	}
+
+	/* Test two MBR partitions */
+	init_write_buffers(mbr_wbuf, sizeof(mbr_wbuf), ebr_wbuf, sizeof(ebr_wbuf), __LINE__);
+	ut_assertok(build_mbr_parts(mbr_parts_buf, sizeof(mbr_parts_buf), 2));
+	ut_assertok(run_commandf("write mmc 6:0 0x%lx 0 1", mbr_wa));
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0 1", ra));
+	ut_assertok(memcmp(mbr_wbuf, rbuf, 512));
+	ut_assertok(run_commandf("write mmc 6:0 0x%lx 0x%lx 1", ebr_wa, ebr_blk));
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0x%lx 1", ra, ebr_blk));
+	ut_assertok(memcmp(ebr_wbuf, rbuf, 512));
+	ut_assertok(console_record_reset_enable());
+	ut_assertf(0 == run_commandf(mbr_parts_buf), "Invalid partitions string: %s\n", mbr_parts_buf);
+	ut_assertok(run_commandf("mbr write mmc 6"));
+	ut_assert_nextline("MBR: write success!");
+	ut_assertok(run_commandf("mbr verify mmc 6"));
+	ut_assert_nextline("MBR: verify success!");
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0x%lx 1", ra, ebr_blk));
+	ut_assertok(memcmp(ebr_wbuf, rbuf, 512));
+	ut_assertok(ut_check_console_end(uts));
+	/*
+	000001b0  00 00 00 00 00 00 00 00  78 56 34 12 00 00 80 05  |........xV4.....|
+	000001c0  05 01 0e 25 24 01 00 40  00 00 00 08 00 00 00 25  |...%$..@.......%|
+	000001d0  25 01 0e 46 05 01 00 48  00 00 00 08 00 00 00 00  |%..F...H........|
+	000001e0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
+	000001f0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 55 aa  |..............U.|
+	*/
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0 1", ra));
+	for (unsigned i = 0; i < mbr_cmp_size; i++) {
+		ut_assertf(rbuf[mbr_cmp_start + i] == mbr_parts_ref_p2[i],
+			"2P MBR+0x%04X: expected 0x%02X, actual: 0x%02X\n",
+			mbr_cmp_start + i, mbr_parts_ref_p2[i], rbuf[mbr_cmp_start + i]);
+	}
+
+	/* Test three MBR partitions */
+	init_write_buffers(mbr_wbuf, sizeof(mbr_wbuf), ebr_wbuf, sizeof(ebr_wbuf), __LINE__);
+	ut_assertok(build_mbr_parts(mbr_parts_buf, sizeof(mbr_parts_buf), 3));
+	ut_assertok(run_commandf("write mmc 6:0 0x%lx 0 1", mbr_wa));
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0 1", ra));
+	ut_assertok(memcmp(mbr_wbuf, rbuf, 512));
+	ut_assertok(run_commandf("write mmc 6:0 0x%lx 0x%lx 1", ebr_wa, ebr_blk));
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0x%lx 1", ra, ebr_blk));
+	ut_assertok(memcmp(ebr_wbuf, rbuf, 512));
+	ut_assertok(console_record_reset_enable());
+	ut_assertf(0 == run_commandf(mbr_parts_buf), "Invalid partitions string: %s\n", mbr_parts_buf);
+	ut_assertok(run_commandf("mbr write mmc 6"));
+	ut_assert_nextline("MBR: write success!");
+	ut_assertok(run_commandf("mbr verify mmc 6"));
+	ut_assert_nextline("MBR: verify success!");
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0x%lx 1", ra, ebr_blk));
+	ut_assertok(memcmp(ebr_wbuf, rbuf, 512));
+	ut_assertok(ut_check_console_end(uts));
+	/*
+	000001b0  00 00 00 00 00 00 00 00  78 56 34 12 00 00 80 05  |........xV4.....|
+	000001c0  05 01 0e 25 24 01 00 40  00 00 00 08 00 00 00 25  |...%$..@.......%|
+	000001d0  25 01 0e 46 05 01 00 48  00 00 00 08 00 00 00 46  |%..F...H.......F|
+	000001e0  06 01 0e 66 25 01 00 50  00 00 00 08 00 00 00 00  |...f%..P........|
+	000001f0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 55 aa  |..............U.|
+	*/
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0 1", ra));
+	for (unsigned i = 0; i < mbr_cmp_size; i++) {
+		ut_assertf(rbuf[mbr_cmp_start + i] == mbr_parts_ref_p3[i],
+			"3P MBR+0x%04X: expected 0x%02X, actual: 0x%02X\n",
+			mbr_cmp_start + i, mbr_parts_ref_p3[i], rbuf[mbr_cmp_start + i]);
+	}
+
+	/* Test four MBR partitions */
+	init_write_buffers(mbr_wbuf, sizeof(mbr_wbuf), ebr_wbuf, sizeof(ebr_wbuf), __LINE__);
+	ut_assertok(build_mbr_parts(mbr_parts_buf, sizeof(mbr_parts_buf), 4));
+	ut_assertok(run_commandf("write mmc 6:0 0x%lx 0 1", mbr_wa));
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0 1", ra));
+	ut_assertok(memcmp(mbr_wbuf, rbuf, 512));
+	ut_assertok(run_commandf("write mmc 6:0 0x%lx 0x%lx 1", ebr_wa, ebr_blk));
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0x%lx 1", ra, ebr_blk));
+	ut_assertok(memcmp(ebr_wbuf, rbuf, 512));
+	ut_assertok(console_record_reset_enable());
+	ut_assertf(0 == run_commandf(mbr_parts_buf), "Invalid partitions string: %s\n", mbr_parts_buf);
+	ut_assertok(run_commandf("mbr write mmc 6"));
+	ut_assert_nextline("MBR: write success!");
+	ut_assertok(run_commandf("mbr verify mmc 6"));
+	ut_assert_nextline("MBR: verify success!");
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0x%lx 1", ra, ebr_blk));
+	ut_assertok(memcmp(ebr_wbuf, rbuf, 512));
+	ut_assertok(ut_check_console_end(uts));
+	/*
+	000001b0  00 00 00 00 00 00 00 00  78 56 34 12 00 00 80 05  |........xV4.....|
+	000001c0  05 01 0e 25 24 01 00 40  00 00 00 08 00 00 00 25  |...%$..@.......%|
+	000001d0  25 01 0e 46 05 01 00 48  00 00 00 08 00 00 00 46  |%..F...H.......F|
+	000001e0  06 01 0e 66 25 01 00 50  00 00 00 08 00 00 00 66  |...f%..P.......f|
+	000001f0  26 01 0e 87 06 01 00 58  00 00 00 08 00 00 55 aa  |&......X......U.|
+	*/
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0 1", ra));
+	for (unsigned i = 0; i < mbr_cmp_size; i++) {
+		ut_assertf(rbuf[mbr_cmp_start + i] == mbr_parts_ref_p4[i],
+			"4P MBR+0x%04X: expected 0x%02X, actual: 0x%02X\n",
+			mbr_cmp_start + i, mbr_parts_ref_p4[i], rbuf[mbr_cmp_start + i]);
+	}
+
+	/* Test five MBR partitions */
+	init_write_buffers(mbr_wbuf, sizeof(mbr_wbuf), ebr_wbuf, sizeof(ebr_wbuf), __LINE__);
+	ut_assertok(build_mbr_parts(mbr_parts_buf, sizeof(mbr_parts_buf), 5));
+	ut_assertok(run_commandf("write mmc 6:0 0x%lx 0 1", mbr_wa));
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0 1", ra));
+	ut_assertok(memcmp(mbr_wbuf, rbuf, 512));
+	ut_assertok(run_commandf("write mmc 6:0 0x%lx 0x%lx 1", ebr_wa, ebr_blk));
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0x%lx 1", ra, ebr_blk));
+	ut_assertok(memcmp(ebr_wbuf, rbuf, 512));
+	ut_assertok(console_record_reset_enable());
+	ut_assertf(0 == run_commandf(mbr_parts_buf), "Invalid partitions string: %s\n", mbr_parts_buf);
+	ut_assertf(0 == run_commandf("mbr write mmc 6"), "Invalid partitions string: %s\n", mbr_parts_buf);
+	ut_assert_nextline("MBR: write success!");
+	ut_assertok(run_commandf("mbr verify mmc 6"));
+	ut_assert_nextline("MBR: verify success!");
+	ut_assertok(ut_check_console_end(uts));
+	/*
+	000001b0  00 00 00 00 00 00 00 00  78 56 34 12 00 00 80 05  |........xV4.....|
+	000001c0  05 01 0e 25 24 01 00 40  00 00 00 08 00 00 00 25  |...%$..@.......%|
+	000001d0  25 01 0e 46 05 01 00 48  00 00 00 08 00 00 00 46  |%..F...H.......F|
+	000001e0  06 01 0e 66 25 01 00 50  00 00 00 08 00 00 00 66  |...f%..P.......f|
+	000001f0  26 01 05 a7 26 01 00 58  00 00 00 10 00 00 55 aa  |&...&..X......U.|
+	*/
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0 1", ra));
+	for (unsigned i = 0; i < mbr_cmp_size; i++) {
+		ut_assertf(rbuf[mbr_cmp_start + i] == mbr_parts_ref_p5[i],
+			"5P MBR+0x%04X: expected 0x%02X, actual: 0x%02X\n",
+			mbr_cmp_start + i, mbr_parts_ref_p5[i], rbuf[mbr_cmp_start + i]);
+	}
+	/*
+	00b001b0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 87  |................|
+	00b001c0  07 01 0e a7 26 01 00 08  00 00 00 08 00 00 00 00  |....&...........|
+	00b001d0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
+	00b001e0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
+	00b001f0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 55 aa  |..............U.|
+	*/
+	memset(rbuf, 0, sizeof(rbuf));
+	ut_assertok(run_commandf("read mmc 6:0 0x%lx 0x%lx 1", ra, ebr_blk));
+	for (unsigned i = 0; i < ebr_cmp_size; i++) {
+		ut_assertf(rbuf[ebr_cmp_start + i] == ebr_parts_ref_p5[i],
+			"5P EBR+0x%04X: expected 0x%02X, actual: 0x%02X\n",
+			ebr_cmp_start + i, ebr_parts_ref_p5[i], rbuf[ebr_cmp_start + i]);
+	}
+
+	return 0;
+}
+
+/* Declare mbr test */
+UNIT_TEST(mbr_test_run, UT_TESTF_CONSOLE_REC, mbr_test);
+
+int do_ut_mbr(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
+{
+	struct unit_test *tests = UNIT_TEST_SUITE_START(mbr_test);
+	const int n_ents = UNIT_TEST_SUITE_COUNT(mbr_test);
+
+	return cmd_ut_category("mbr", "mbr_test_", tests, n_ents, argc, argv);
+}
+
+static int dm_test_cmd_mbr(struct unit_test_state *uts)
+{
+	return mbr_test_run(uts);
+}
+
+DM_TEST(dm_test_cmd_mbr, UT_TESTF_SCAN_FDT | UT_TESTF_CONSOLE_REC);
diff --git a/test/cmd_ut.c b/test/cmd_ut.c
index 477d475..0343d47 100644
--- a/test/cmd_ut.c
+++ b/test/cmd_ut.c
@@ -87,6 +87,10 @@ static struct cmd_tbl cmd_ut_sub[] = {
 #ifdef CONFIG_UT_LOG
 	U_BOOT_CMD_MKENT(log, CONFIG_SYS_MAXARGS, 1, do_ut_log, "", ""),
 #endif
+#if defined(CONFIG_SANDBOX) && defined(CONFIG_CMD_MBR) && defined(CONFIG_CMD_MMC) \
+        && defined(CONFIG_MMC_SANDBOX) && defined(CONFIG_MMC_WRITE)
+	U_BOOT_CMD_MKENT(mbr, CONFIG_SYS_MAXARGS, 1, do_ut_mbr, "", ""),
+#endif
 	U_BOOT_CMD_MKENT(mem, CONFIG_SYS_MAXARGS, 1, do_ut_mem, "", ""),
 #if defined(CONFIG_SANDBOX) && defined(CONFIG_CMD_SETEXPR)
 	U_BOOT_CMD_MKENT(setexpr, CONFIG_SYS_MAXARGS, 1, do_ut_setexpr, "",
diff --git a/test/py/tests/test_ut.py b/test/py/tests/test_ut.py
index 82932a6..1d9149a 100644
--- a/test/py/tests/test_ut.py
+++ b/test/py/tests/test_ut.py
@@ -433,7 +433,6 @@ def setup_cedit_file(cons):
     u_boot_utils.run_and_log(
         cons, f'{expo_tool} -e {inhname} -l {infname} -o {outfname}')
 
-
 @pytest.mark.buildconfigspec('ut_dm')
 def test_ut_dm_init(u_boot_console):
     """Initialize data for ut dm tests."""
@@ -463,6 +462,12 @@ def test_ut_dm_init(u_boot_console):
     fs_helper.mk_fs(u_boot_console.config, 'ext2', 0x200000, '2MB')
     fs_helper.mk_fs(u_boot_console.config, 'fat32', 0x100000, '1MB')
 
+    mmc_dev = 6
+    fn = os.path.join(u_boot_console.config.source_dir, f'mmc{mmc_dev}.img')
+    data = b'\x00' * (12 * 1024 * 1024)
+    with open(fn, 'wb') as fh:
+        fh.write(data)
+
 @pytest.mark.buildconfigspec('cmd_bootflow')
 def test_ut_dm_init_bootstd(u_boot_console):
     """Initialise data for bootflow tests"""