[U-Boot] [PATCH 2/2] lib: Add hexdump

Alexey Brodkin Alexey.Brodkin at synopsys.com
Fri Jun 10 14:39:31 CEST 2016


Often during debugging session it's very interesting to see
what data we were dealing with. For example what we write or read
to/from memory or peripherals.

This change introduces functions that allow to dump binary
data with one simple function invocation like:
------------------->8----------------
print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, buf, len);
------------------->8----------------

which gives us the following:
------------------->8----------------
00000000: f2 b7 c9 88 62 61 75 64 72 61 74 65 3d 31 31 35  ....baudrate=115
00000010: 32 30 30 00 62 6f 6f 74 61 72 67 73 3d 63 6f 6e  200.bootargs=con
00000020: 73 6f 6c 65 3d 74 74 79 53 33 2c 31 31 35 32 30  sole=ttyS3,11520
00000030: 30 6e 38 00 62 6f 6f 74 64 65 6c 61 79 3d 33 00  0n8.bootdelay=3.
00000040: 62 6f 6f 74 66 69 6c 65 3d 75 49 6d 61 67 65 00  bootfile=uImage.
00000050: 66 64 74 63 6f 6e 74 72 6f 6c 61 64 64 72 3d 39  fdtcontroladdr=9
00000060: 66 66 62 31 62 61 30 00 6c 6f 61 64 61 64 64 72  ffb1ba0.loadaddr
00000070: 3d 30 78 38 32 30 30 30 30 30 30 00 73 74 64 65  =0x82000000.stde
00000080: 72 72 3d 73 65 72 69 61 6c 30 40 65 30 30 32 32  rr=serial0 at e0022
00000090: 30 30 30 00 73 74 64 69 6e 3d 73 65 72 69 61 6c  000.stdin=serial
000000a0: 30 40 65 30 30 32 32 30 30 30 00 73 74 64 6f 75  0 at e0022000.stdou
000000b0: 74 3d 73 65 72 69 61 6c 30 40 65 30 30 32 32 30  t=serial0 at e00220
000000c0: 30 30 00 00 00 00 00 00 00 00 00 00 00 00 00 00  00..............
...
------------------->8----------------

Source of hexdump.c was copied from Linux kernel v4.7-rc2.

Signed-off-by: Alexey Brodkin <abrodkin at synopsys.com>
Reviewed-by: Stefan Roese <sr at denx.de>
Cc: Tom Rini <trini at konsulko.com>

---

Changes v1 -> v2:
 * Move hexdump definitions to a separate header.
 * Move helper funcions to the header so they might be used even if
   CONFIG_HEXDUMP is not enabled and if not used they will not occupy
   extra bytes of memory being "static inline" ones.
 * While at it replace its own hex_asc[], hex_asc_{lo|hi}() and
   pack_hex_byte() in lib/vsprintf.c with generic ones from hexdump.
 * In print_hex_dump() revert back first parametr for debug level,
   otherwise existing users of the function will be broken.

 include/common.h       |   1 +
 include/hexdump.h      | 108 +++++++++++++++++++++++
 include/linux/compat.h |   1 -
 lib/Kconfig            |   5 ++
 lib/Makefile           |   1 +
 lib/hexdump.c          | 233 +++++++++++++++++++++++++++++++++++++++++++++++++
 lib/vsprintf.c         |  17 +---
 7 files changed, 351 insertions(+), 15 deletions(-)
 create mode 100644 include/hexdump.h
 create mode 100644 lib/hexdump.c

diff --git a/include/common.h b/include/common.h
index f9f4605..51a438c 100644
--- a/include/common.h
+++ b/include/common.h
@@ -23,6 +23,7 @@ typedef volatile unsigned char	vu_char;
 #include <linux/stringify.h>
 #include <asm/ptrace.h>
 #include <stdarg.h>
+#include <hexdump.h>
 #include <linux/kernel.h>
 #if defined(CONFIG_PCI) && defined(CONFIG_4xx)
 #include <pci.h>
diff --git a/include/hexdump.h b/include/hexdump.h
new file mode 100644
index 0000000..de2e565
--- /dev/null
+++ b/include/hexdump.h
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2016 Synopsys, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef HEXDUMP_H
+#define HEXDUMP_H
+
+#include <linux/ctype.h>
+
+enum {
+	DUMP_PREFIX_NONE,
+	DUMP_PREFIX_ADDRESS,
+	DUMP_PREFIX_OFFSET
+};
+
+extern const char hex_asc[];
+#define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
+#define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
+
+static inline char *hex_byte_pack(char *buf, u8 byte)
+{
+	*buf++ = hex_asc_hi(byte);
+	*buf++ = hex_asc_lo(byte);
+	return buf;
+}
+
+/**
+ * hex_to_bin - convert a hex digit to its real value
+ * @ch: ascii character represents hex digit
+ *
+ * hex_to_bin() converts one hex digit to its actual value or -1 in case of bad
+ * input.
+ */
+static inline int hex_to_bin(char ch)
+{
+	if ((ch >= '0') && (ch <= '9'))
+		return ch - '0';
+	ch = tolower(ch);
+	if ((ch >= 'a') && (ch <= 'f'))
+		return ch - 'a' + 10;
+	return -1;
+}
+
+/**
+ * hex2bin - convert an ascii hexadecimal string to its binary representation
+ * @dst: binary result
+ * @src: ascii hexadecimal string
+ * @count: result length
+ *
+ * Return 0 on success, -1 in case of bad input.
+ */
+static inline int hex2bin(u8 *dst, const char *src, size_t count)
+{
+	while (count--) {
+		int hi = hex_to_bin(*src++);
+		int lo = hex_to_bin(*src++);
+
+		if ((hi < 0) || (lo < 0))
+			return -1;
+
+		*dst++ = (hi << 4) | lo;
+	}
+	return 0;
+}
+
+/**
+ * bin2hex - convert binary data to an ascii hexadecimal string
+ * @dst: ascii hexadecimal result
+ * @src: binary data
+ * @count: binary data length
+ */
+static inline char *bin2hex(char *dst, const void *src, size_t count)
+{
+	const unsigned char *_src = src;
+
+	while (count--)
+		dst = hex_byte_pack(dst, *_src++);
+	return dst;
+}
+
+
+#ifdef CONFIG_HEXDUMP
+int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
+		       char *linebuf, size_t linebuflen, bool ascii);
+void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
+		    int rowsize, int groupsize, const void *buf, size_t len,
+		    bool ascii);
+void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
+			  const void *buf, size_t len);
+#else /* !CONFIG_HEXDUMP */
+/*
+ * Some code in U-Boot copy-pasted from Linux kernel uses both
+ * functions below so to keep stuff compilable we keep these stubs here.
+ */
+static inline void print_hex_dump(const char *level, const char *prefix_str,
+				  int prefix_type, int rowsize, int groupsize,
+				  const void *buf, size_t len, bool ascii)
+{
+}
+static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
+					const void *buf, size_t len)
+{
+}
+#endif /* CONFIG_HEXDUMP */
+
+#endif /* HEXDUMP_H */
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 0ce7d65..074a85e 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -193,7 +193,6 @@ typedef unsigned long blkcnt_t;
 #define init_waitqueue_head(...)	do { } while (0)
 #define wait_event_interruptible(...)	0
 #define wake_up_interruptible(...)	do { } while (0)
-#define print_hex_dump(...)		do { } while (0)
 #define dump_stack(...)			do { } while (0)
 
 #define task_pid_nr(x)			0
diff --git a/lib/Kconfig b/lib/Kconfig
index 2b97c2b..a563b5e 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -128,6 +128,11 @@ config ERRNO_STR
 	  - if errno is null or positive number - a pointer to "Success" message
 	  - if errno is negative - a pointer to errno related message
 
+config HEXDUMP
+	bool "Enable hexdump"
+	help
+	  This enables functions for printing dumps of binary data.
+
 config OF_LIBFDT
 	bool "Enable the FDT library"
 	default y if OF_CONTROL
diff --git a/lib/Makefile b/lib/Makefile
index 02dfa29..1bf7c37 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -76,6 +76,7 @@ obj-y += membuff.o
 obj-$(CONFIG_REGEX) += slre.o
 obj-y += string.o
 obj-y += time.o
+obj-y += hexdump.o
 obj-$(CONFIG_TRACE) += trace.o
 obj-$(CONFIG_LIB_UUID) += uuid.o
 obj-$(CONFIG_LIB_RAND) += rand.o
diff --git a/lib/hexdump.c b/lib/hexdump.c
new file mode 100644
index 0000000..ffee5ce
--- /dev/null
+++ b/lib/hexdump.c
@@ -0,0 +1,233 @@
+/*
+ * lib/hexdump.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation. See README and COPYING for
+ * more details.
+ */
+
+#include <common.h>
+#include <linux/ctype.h>
+#include <linux/compat.h>
+#include <linux/log2.h>
+#include <asm/unaligned.h>
+
+const char hex_asc[] = "0123456789abcdef";
+const char hex_asc_upper[] = "0123456789ABCDEF";
+
+#ifdef CONFIG_HEXDUMP
+/**
+ * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory
+ * @buf: data blob to dump
+ * @len: number of bytes in the @buf
+ * @rowsize: number of bytes to print per line; must be 16 or 32
+ * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
+ * @linebuf: where to put the converted data
+ * @linebuflen: total size of @linebuf, including space for terminating NUL
+ * @ascii: include ASCII after the hex output
+ *
+ * hex_dump_to_buffer() works on one "line" of output at a time, i.e.,
+ * 16 or 32 bytes of input data converted to hex + ASCII output.
+ *
+ * Given a buffer of u8 data, hex_dump_to_buffer() converts the input data
+ * to a hex + ASCII dump at the supplied memory location.
+ * The converted output is always NUL-terminated.
+ *
+ * E.g.:
+ *   hex_dump_to_buffer(frame->data, frame->len, 16, 1,
+ *			linebuf, sizeof(linebuf), true);
+ *
+ * example output buffer:
+ * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f  @ABCDEFGHIJKLMNO
+ *
+ * Return:
+ * The amount of bytes placed in the buffer without terminating NUL. If the
+ * output was truncated, then the return value is the number of bytes
+ * (excluding the terminating NUL) which would have been written to the final
+ * string if enough space had been available.
+ */
+int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
+		       char *linebuf, size_t linebuflen, bool ascii)
+{
+	const u8 *ptr = buf;
+	int ngroups;
+	u8 ch;
+	int j, lx = 0;
+	int ascii_column;
+	int ret;
+
+	if (rowsize != 16 && rowsize != 32)
+		rowsize = 16;
+
+	if (len > rowsize)		/* limit to one line at a time */
+		len = rowsize;
+	if (!is_power_of_2(groupsize) || groupsize > 8)
+		groupsize = 1;
+	if ((len % groupsize) != 0)	/* no mixed size output */
+		groupsize = 1;
+
+	ngroups = len / groupsize;
+	ascii_column = rowsize * 2 + rowsize / groupsize + 1;
+
+	if (!linebuflen)
+		goto overflow1;
+
+	if (!len)
+		goto nil;
+
+	if (groupsize == 8) {
+		const u64 *ptr8 = buf;
+
+		for (j = 0; j < ngroups; j++) {
+			ret = snprintf(linebuf + lx, linebuflen - lx,
+				       "%s%16.16llx", j ? " " : "",
+				       get_unaligned(ptr8 + j));
+			if (ret >= linebuflen - lx)
+				goto overflow1;
+			lx += ret;
+		}
+	} else if (groupsize == 4) {
+		const u32 *ptr4 = buf;
+
+		for (j = 0; j < ngroups; j++) {
+			ret = snprintf(linebuf + lx, linebuflen - lx,
+				       "%s%8.8x", j ? " " : "",
+				       get_unaligned(ptr4 + j));
+			if (ret >= linebuflen - lx)
+				goto overflow1;
+			lx += ret;
+		}
+	} else if (groupsize == 2) {
+		const u16 *ptr2 = buf;
+
+		for (j = 0; j < ngroups; j++) {
+			ret = snprintf(linebuf + lx, linebuflen - lx,
+				       "%s%4.4x", j ? " " : "",
+				       get_unaligned(ptr2 + j));
+			if (ret >= linebuflen - lx)
+				goto overflow1;
+			lx += ret;
+		}
+	} else {
+		for (j = 0; j < len; j++) {
+			if (linebuflen < lx + 2)
+				goto overflow2;
+			ch = ptr[j];
+			linebuf[lx++] = hex_asc_hi(ch);
+			if (linebuflen < lx + 2)
+				goto overflow2;
+			linebuf[lx++] = hex_asc_lo(ch);
+			if (linebuflen < lx + 2)
+				goto overflow2;
+			linebuf[lx++] = ' ';
+		}
+		if (j)
+			lx--;
+	}
+	if (!ascii)
+		goto nil;
+
+	while (lx < ascii_column) {
+		if (linebuflen < lx + 2)
+			goto overflow2;
+		linebuf[lx++] = ' ';
+	}
+	for (j = 0; j < len; j++) {
+		if (linebuflen < lx + 2)
+			goto overflow2;
+		ch = ptr[j];
+		linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';
+	}
+nil:
+	linebuf[lx] = '\0';
+	return lx;
+overflow2:
+	linebuf[lx++] = '\0';
+overflow1:
+	return ascii ? ascii_column + len : (groupsize * 2 + 1) * ngroups - 1;
+}
+
+/**
+ * print_hex_dump - print a text hex dump to syslog for a binary blob of data
+ * @level: kernel log level (e.g. KERN_DEBUG)
+ * @prefix_str: string to prefix each line with;
+ *  caller supplies trailing spaces for alignment if desired
+ * @prefix_type: controls whether prefix of an offset, address, or none
+ *  is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
+ * @rowsize: number of bytes to print per line; must be 16 or 32
+ * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
+ * @buf: data blob to dump
+ * @len: number of bytes in the @buf
+ * @ascii: include ASCII after the hex output
+ *
+ * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump
+ * to the kernel log at the specified kernel log level, with an optional
+ * leading prefix.
+ *
+ * print_hex_dump() works on one "line" of output at a time, i.e.,
+ * 16 or 32 bytes of input data converted to hex + ASCII output.
+ * print_hex_dump() iterates over the entire input @buf, breaking it into
+ * "line size" chunks to format and print.
+ *
+ * E.g.:
+ *   print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS,
+ *		    16, 1, frame->data, frame->len, true);
+ *
+ * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode:
+ * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f  @ABCDEFGHIJKLMNO
+ * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode:
+ * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c  pqrstuvwxyz{|}~.
+ */
+void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
+		    int rowsize, int groupsize,
+		    const void *buf, size_t len, bool ascii)
+{
+	const u8 *ptr = buf;
+	int i, linelen, remaining = len;
+	char linebuf[32 * 3 + 2 + 32 + 1];
+
+	if (rowsize != 16 && rowsize != 32)
+		rowsize = 16;
+
+	for (i = 0; i < len; i += rowsize) {
+		linelen = min(remaining, rowsize);
+		remaining -= rowsize;
+
+		hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
+				   linebuf, sizeof(linebuf), ascii);
+
+		switch (prefix_type) {
+		case DUMP_PREFIX_ADDRESS:
+			printf("%s%p: %s\n", prefix_str, ptr + i, linebuf);
+			break;
+		case DUMP_PREFIX_OFFSET:
+			printf("%s%.8x: %s\n", prefix_str, i, linebuf);
+			break;
+		default:
+			printf("%s%s\n", prefix_str, linebuf);
+			break;
+		}
+	}
+}
+
+/**
+ * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params
+ * @prefix_str: string to prefix each line with;
+ *  caller supplies trailing spaces for alignment if desired
+ * @prefix_type: controls whether prefix of an offset, address, or none
+ *  is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
+ * @buf: data blob to dump
+ * @len: number of bytes in the @buf
+ *
+ * Calls print_hex_dump(), with log level of KERN_DEBUG,
+ * rowsize of 16, groupsize of 1, and ASCII output included.
+ */
+void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
+			  const void *buf, size_t len)
+{
+	print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1,
+		       buf, len, true);
+}
+
+#endif /* CONFIG_HEXDUMP */
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 874a295..c0a0aaa 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -271,17 +271,6 @@ static char *string(char *buf, char *end, char *s, int field_width,
 }
 
 #ifdef CONFIG_CMD_NET
-static const char hex_asc[] = "0123456789abcdef";
-#define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
-#define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
-
-static inline char *pack_hex_byte(char *buf, u8 byte)
-{
-	*buf++ = hex_asc_hi(byte);
-	*buf++ = hex_asc_lo(byte);
-	return buf;
-}
-
 static char *mac_address_string(char *buf, char *end, u8 *addr, int field_width,
 				int precision, int flags)
 {
@@ -291,7 +280,7 @@ static char *mac_address_string(char *buf, char *end, u8 *addr, int field_width,
 	int i;
 
 	for (i = 0; i < 6; i++) {
-		p = pack_hex_byte(p, addr[i]);
+		p = hex_byte_pack(p, addr[i]);
 		if (!(flags & SPECIAL) && i != 5)
 			*p++ = ':';
 	}
@@ -310,8 +299,8 @@ static char *ip6_addr_string(char *buf, char *end, u8 *addr, int field_width,
 	int i;
 
 	for (i = 0; i < 8; i++) {
-		p = pack_hex_byte(p, addr[2 * i]);
-		p = pack_hex_byte(p, addr[2 * i + 1]);
+		p = hex_byte_pack(p, addr[2 * i]);
+		p = hex_byte_pack(p, addr[2 * i + 1]);
 		if (!(flags & SPECIAL) && i != 7)
 			*p++ = ':';
 	}
-- 
2.5.5



More information about the U-Boot mailing list