cmd: xxd: add new command

Add xxd command to print file content as hexdump to standard out

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Roger Knecht <rknecht@pm.me>

MAINTAINERS

@@ -1519,6 +1519,13 @@ M:	Max Filippov <jcmvbkbc@gmail.com>
 S:	Maintained
 F:	arch/xtensa/
 
+XXD
+M:	Roger Knecht <rknecht@pm.me>
+S:	Maintained
+F:	cmd/xxd.c
+F:	doc/usage/cmd/xxd.rst
+F:	test/py/tests/test_xxd/
+
 THE REST
 M:	Tom Rini <trini@konsulko.com>
 L:	u-boot@lists.denx.de

cmd/Kconfig

@@ -469,6 +469,11 @@ config CMD_XIMG
 	help
 	  Extract a part of a multi-image.
 
+config CMD_XXD
+	bool "xxd"
+	help
+	  Print file as hexdump to standard output
+
 config CMD_SPL
 	bool "spl export - Export boot information for Falcon boot"
 	depends on SPL

cmd/Makefile

@@ -185,6 +185,7 @@ obj-$(CONFIG_CMD_USB_SDP) += usb_gadget_sdp.o
 obj-$(CONFIG_CMD_THOR_DOWNLOAD) += thordown.o
 obj-$(CONFIG_CMD_VBE) += vbe.o
 obj-$(CONFIG_CMD_XIMG) += ximg.o
+obj-$(CONFIG_CMD_XXD) += xxd.o
 obj-$(CONFIG_CMD_YAFFS2) += yaffs2.o
 obj-$(CONFIG_CMD_SPL) += spl.o
 obj-$(CONFIG_CMD_W1) += w1.o

cmd/xxd.c

@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2022
+ * Roger Knecht <rknecht@pm.de>
+ */
+
+#include <common.h>
+#include <command.h>
+#include <display_options.h>
+#include <fs.h>
+#include <malloc.h>
+#include <mapmem.h>
+
+static int do_xxd(struct cmd_tbl *cmdtp, int flag, int argc,
+		  char *const argv[])
+{
+	char *ifname;
+	char *dev;
+	char *file;
+	char *buffer;
+	phys_addr_t addr;
+	loff_t file_size;
+
+	if (argc < 4)
+		return CMD_RET_USAGE;
+
+	ifname = argv[1];
+	dev = argv[2];
+	file = argv[3];
+
+	// check file exists
+	if (fs_set_blk_dev(ifname, dev, FS_TYPE_ANY))
+		return CMD_RET_FAILURE;
+
+	if (!fs_exists(file)) {
+		log_err("File does not exist: ifname=%s dev=%s file=%s\n", ifname, dev, file);
+		return CMD_RET_FAILURE;
+	}
+
+	// get file size
+	if (fs_set_blk_dev(ifname, dev, FS_TYPE_ANY))
+		return CMD_RET_FAILURE;
+
+	if (fs_size(file, &file_size)) {
+		log_err("Cannot read file size: ifname=%s dev=%s file=%s\n", ifname, dev, file);
+		return CMD_RET_FAILURE;
+	}
+
+	// allocate memory for file content
+	buffer = calloc(sizeof(char), file_size);
+	if (!buffer) {
+		log_err("Out of memory\n");
+		return CMD_RET_FAILURE;
+	}
+
+	// map pointer to system memory
+	addr = map_to_sysmem(buffer);
+
+	// read file to memory
+	if (fs_set_blk_dev(ifname, dev, FS_TYPE_ANY))
+		return CMD_RET_FAILURE;
+
+	if (fs_read(file, addr, 0, 0, &file_size)) {
+		log_err("Cannot read file: ifname=%s dev=%s file=%s\n", ifname, dev, file);
+		return CMD_RET_FAILURE;
+	}
+
+	// print file content
+	print_buffer(0, buffer, sizeof(char), file_size, 0);
+
+	free(buffer);
+
+	return 0;
+}
+
+#ifdef CONFIG_SYS_LONGHELP
+static char xxd_help_text[] =
+	"<interface> <dev[:part]> <file>\n"
+	"  - Print file from 'dev' on 'interface' as hexdump to standard output\n";
+#endif
+
+U_BOOT_CMD(xxd, 4, 1, do_xxd,
+	   "Print file as hexdump to standard output",
+	   xxd_help_text
+);

configs/sandbox64_defconfig

@@ -55,6 +55,7 @@ CONFIG_CMD_READ=y
 CONFIG_CMD_REMOTEPROC=y
 CONFIG_CMD_SPI=y
 CONFIG_CMD_USB=y
+CONFIG_CMD_XXD=y
 CONFIG_BOOTP_DNS2=y
 CONFIG_CMD_TFTPPUT=y
 CONFIG_CMD_TFTPSRV=y

configs/sandbox_defconfig

@@ -61,6 +61,7 @@ CONFIG_CMD_MEM_SEARCH=y
 CONFIG_CMD_MX_CYCLIC=y
 CONFIG_CMD_MEMTEST=y
 CONFIG_CMD_UNZIP=y
+CONFIG_CMD_XXD=y
 CONFIG_CMD_BIND=y
 CONFIG_CMD_DEMO=y
 CONFIG_CMD_GPIO=y

doc/usage/cmd/xxd.rst

@@ -0,0 +1,50 @@
+.. SPDX-License-Identifier: GPL-2.0+:
+
+xxd command
+===============
+
+Synopsis
+--------
+
+::
+
+    xxd <interface> <dev[:part]> <file>
+
+Description
+-----------
+
+The xxd command prints the file content as hexdump to standard out.
+
+interface
+    interface for accessing the block device (mmc, sata, scsi, usb, ....)
+
+dev
+    device number
+
+part
+    partition number, defaults to 1
+
+file
+    path to file
+
+Example
+-------
+
+Here is the output for a example text file:
+
+::
+
+    => xxd mmc 0:1 hello
+    00000000: 68 65 6c 6c 6f 20 77 6f 72 6c 64 0a 00 01 02 03  hello world.....
+    00000010: 04 05                                            ..
+    =>
+
+Configuration
+-------------
+
+The xxd command is only available if CONFIG_CMD_XXD=y.
+
+Return value
+------------
+
+The return value $? is set to 0 (true) if the file is readable, otherwise it returns a non-zero error code.

doc/usage/index.rst

@@ -72,6 +72,7 @@ Shell commands
    cmd/true
    cmd/ums
    cmd/wdt
+   cmd/xxd
 
 Booting OS
 ----------

test/py/tests/test_xxd/conftest.py

@@ -0,0 +1,35 @@
+# SPDX-License-Identifier:      GPL-2.0+
+
+"""Fixture for xxd command test
+"""
+
+import os
+import shutil
+from subprocess import check_call, CalledProcessError
+import pytest
+
+@pytest.fixture(scope='session')
+def xxd_data(u_boot_config):
+    """Set up a file system to be used in xxd tests
+
+    Args:
+        u_boot_config -- U-boot configuration.
+    """
+    mnt_point = u_boot_config.persistent_data_dir + '/test_xxd'
+    image_path = u_boot_config.persistent_data_dir + '/xxd.img'
+
+    try:
+        os.mkdir(mnt_point, mode = 0o755)
+
+        with open(mnt_point + '/hello', 'w', encoding = 'ascii') as file:
+            file.write('hello world\n\x00\x01\x02\x03\x04\x05')
+
+        check_call(f'virt-make-fs --partition=gpt --size=+1M --type=vfat {mnt_point} {image_path}',
+                   shell=True)
+
+        yield image_path
+    except CalledProcessError:
+        pytest.skip('Setup failed')
+    finally:
+        shutil.rmtree(mnt_point)
+        os.remove(image_path)

test/py/tests/test_xxd/test_xxd.py

@@ -0,0 +1,23 @@
+# SPDX-License-Identifier:      GPL-2.0+
+
+""" Unit test for xxd command
+"""
+
+import pytest
+
+@pytest.mark.boardspec('sandbox')
+@pytest.mark.buildconfigspec('cmd_xxd')
+def test_xxd(u_boot_console, xxd_data):
+    """ Unit test for xxd
+
+    Args:
+        u_boot_console -- U-Boot console
+        xxd_data -- Path to the disk image used for testing.
+    """
+    response = u_boot_console.run_command_list([
+        f'host bind 0 {xxd_data}',
+        'xxd host 0 hello'])
+
+    assert '00000000: 68 65 6c 6c 6f 20 77 6f 72 6c 64 0a 00 01 02 03  hello world.....\r\r\n' + \
+           '00000010: 04 05                                            ..' \
+           in response