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>

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
+);