printf: Convert %h to %ph

In order to make printf more standard, use %ph. Pass a pointer to
a struct describing the buffer, including its size. Add a convenience
macro so that conversion between the old style and new style is purely
mechanical. The old style of %h cannot be converted directly to %ph as-is
because the C standard doesn't allow flags, precision, or field width on
%p.

Ultimately the goal is to enable compile-time printf format checking.
This gets us one step closer to that.

BUG=chromium:984041
TEST=make -j buildall
BRANCH=None

Cq-Depend:chrome-internal:1559798,chrome-internal:1560598
Change-Id: I9c0ca124a048314c9b62d64bd55b36be55034e0e
Signed-off-by: Evan Green <evgreen@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1730605

20 files changed, 139 insertions, 94 deletions

diff --git a/board/cr50/usb_spi.c b/board/cr50/usb_spi.c
index 9392bec8f7..66083de4b1 100644
--- a/board/cr50/usb_spi.c
+++ b/board/cr50/usb_spi.c
@@ -754,9 +754,9 @@ static int hash_command_wrapper(int argc, char *argv[])
 		rv = EC_SUCCESS;
 
 		if (req.subcmd == SPI_HASH_SUBCMD_DUMP)
-			ccprintf("data: %.*h\n", req.size, p);
+			ccprintf("data: %ph\n", HEX_BUF(p, req.size));
 		else if (req.subcmd == SPI_HASH_SUBCMD_SHA256)
-			ccprintf("hash: %.32h\n", p);
+			ccprintf("hash: %ph\n", HEX_BUF(p, 32));
 	}
 
 	return rv;
diff --git a/chip/g/dcrypto/app_cipher.c b/chip/g/dcrypto/app_cipher.c
index 2d95173c8f..e465598718 100644
--- a/chip/g/dcrypto/app_cipher.c
+++ b/chip/g/dcrypto/app_cipher.c
@@ -282,7 +282,7 @@ static int basic_check(struct test_info *pinfo)
 	int i;
 	uint32_t *p;
 
-	ccprintf("original data  %.16h\n", pinfo->p);
+	ccprintf("original data  %ph\n", HEX_BUF(pinfo->p, 16));
 
 	half = (pinfo->test_blob_size/2) & ~3;
 	if (!DCRYPTO_app_cipher(NVMEM, pinfo->p, pinfo->p,
@@ -301,7 +301,7 @@ static int basic_check(struct test_info *pinfo)
 			return EC_ERROR_UNKNOWN;
 		}
 
-	ccprintf("hashed data    %.16h\n", pinfo->p);
+	ccprintf("hashed data    %ph\n", HEX_BUF(pinfo->p, 16));
 
 	return EC_SUCCESS;
 }
@@ -407,7 +407,7 @@ static void run_cipher_cmd(void)
 		report_stats("Encryption", &info.enc_stats);
 		report_stats("Decryption", &info.dec_stats);
 	} else if (info.p) {
-		ccprintf("current data   %.16h\n", info.p);
+		ccprintf("current data   %ph\n", HEX_BUF(info.p, 16));
 	}
 
 	if (info.p)
diff --git a/chip/g/dcrypto/dcrypto_bn.c b/chip/g/dcrypto/dcrypto_bn.c
index cae54e6adf..2696d37669 100644
--- a/chip/g/dcrypto/dcrypto_bn.c
+++ b/chip/g/dcrypto/dcrypto_bn.c
@@ -1484,8 +1484,8 @@ static int command_genp(int argc, char **argv)
 	result = call_on_bigger_stack(genp_core);
 
 	if (result == EC_SUCCESS) {
-		ccprintf("prime: %.*h (lsb first)\n", sizeof(prime_buf),
-			 prime_buf);
+		ccprintf("prime: %ph (lsb first)\n",
+			 HEX_BUF(prime_buf, sizeof(prime_buf));
 		ccprintf("μs   : %lu\n", genp_end.val - genp_start.val);
 	}
 
diff --git a/chip/g/dcrypto/hmac_drbg.c b/chip/g/dcrypto/hmac_drbg.c
index 64b47a13f5..bf49103e93 100644
--- a/chip/g/dcrypto/hmac_drbg.c
+++ b/chip/g/dcrypto/hmac_drbg.c
@@ -202,7 +202,7 @@ static int cmd_rfc6979(int argc, char **argv)
 	hmac_drbg_init_rfc6979(&drbg, x, &h1);
 	do {
 		hmac_drbg_generate_p256(&drbg, &k);
-		ccprintf("K = %.32h\n", &k);
+		ccprintf("K = %ph\n", HEX_BUF(&k, 32));
 	} while (p256_cmp(&SECP256r1_nMin2, &k) < 0);
 	drbg_exit(&drbg);
 	result = p256_cmp(&k, reference_k);
diff --git a/chip/g/loader/launch.c b/chip/g/loader/launch.c
index cf701a21cb..823e29489b 100644
--- a/chip/g/loader/launch.c
+++ b/chip/g/loader/launch.c
@@ -79,7 +79,7 @@ void tryLaunch(uint32_t adr, size_t max_size)
 			hdr->image_size - offsetof(struct SignedHeader, tag),
 			(uint8_t *) hashes.img_hash);
 
-	VERBOSE("img_hash  : %.32h\n", hashes.img_hash);
+	VERBOSE("img_hash  : %ph\n", HEX_BUF(hashes.img_hash, 32));
 
 	/* Sense fuses into RAM array; hash array. */
 	/* TODO: is this glitch resistant enough? Certainly is simple.. */
@@ -104,7 +104,7 @@ void tryLaunch(uint32_t adr, size_t max_size)
 	DCRYPTO_SHA256_hash((uint8_t *) fuses, sizeof(fuses),
 			(uint8_t *) hashes.fuses_hash);
 
-	VERBOSE("fuses_hash: %.32h\n", hashes.fuses_hash);
+	VERBOSE("fuses_hash: %ph\n", HEX_BUF(hashes.fuses_hash, 32));
 
 	/* Sense info into RAM array; hash array. */
 	for (i = 0; i < INFO_MAX; ++i)
@@ -122,7 +122,7 @@ void tryLaunch(uint32_t adr, size_t max_size)
 
 	DCRYPTO_SHA256_hash((uint8_t *) info, sizeof(info),
 			(uint8_t *) hashes.info_hash);
-	VERBOSE("info_hash : %.32h\n", hashes.info_hash);
+	VERBOSE("info_hash : %ph\n", HEX_BUF(hashes.info_hash, 32));
 
 	/* Hash our set of hashes to get final hash. */
 	DCRYPTO_SHA256_hash((uint8_t *) &hashes, sizeof(hashes),
diff --git a/chip/g/loader/verify.c b/chip/g/loader/verify.c
index 41b1c6cddd..54be724f10 100644
--- a/chip/g/loader/verify.c
+++ b/chip/g/loader/verify.c
@@ -103,7 +103,7 @@ void LOADERKEY_verify(const uint32_t *key, const uint32_t *signature,
 	int i;
 
 	modpow3(key, signature, buf);
-	VERBOSE("sig %.384h\n", buf);
+	VERBOSE("sig %ph\n", HEX_BUF(buf, 384));
 
 	/*
 	 * If key was not 3Kb, assume 2Kb and expand for subsequent
@@ -142,12 +142,12 @@ void LOADERKEY_verify(const uint32_t *key, const uint32_t *signature,
 		offset = (offset + step) % SHA256_DIGEST_WORDS;
 	}
 
-	VERBOSE("\nsig^ %.384h\n\n", buf);
+	VERBOSE("\nsig^ %ph\n\n", HEX_BUF(buf, 384));
 
 	/* Hash resulting buffer. */
 	DCRYPTO_SHA256_hash((uint8_t *) buf, RSA_NUM_BYTES, (uint8_t *) hash);
 
-	VERBOSE("hash %.32h\n", hash);
+	VERBOSE("hash %ph\n", HEX_BUF(hash, 32));
 
 	/*
 	 * Write computed hash to unlock register to unlock execution, iff
diff --git a/chip/it83xx/i2c_slave.c b/chip/it83xx/i2c_slave.c
index 1902285959..adfa794d77 100644
--- a/chip/it83xx/i2c_slave.c
+++ b/chip/it83xx/i2c_slave.c
@@ -173,8 +173,9 @@ void i2c_slave_read_write_data(int port)
 			 * TODO(b:129360157): Handle master write
 			 * data by "in_data" array.
 			 */
-					CPRINTS("WData: %.*h",
-					I2C_MAX_BUFFER_SIZE, in_data[idx]);
+					CPRINTS("WData: %ph",
+						HEX_BUF(in_data[idx],
+							I2C_MAX_BUFFER_SIZE));
 					wr_done[idx] = 0;
 				}
 			}
diff --git a/chip/stm32/trng.c b/chip/stm32/trng.c
index fcc0f5432e..eff3ca0181 100644
--- a/chip/stm32/trng.c
+++ b/chip/stm32/trng.c
@@ -111,7 +111,7 @@ static int command_rand(int argc, char **argv)
 	rand_bytes(data, sizeof(data));
 	exit_trng();
 
-	ccprintf("rand %.*h\n", sizeof(data), data);
+	ccprintf("rand %ph\n", HEX_BUF(data, sizeof(data)));
 
 	return EC_SUCCESS;
 }
diff --git a/common/ccd_config.c b/common/ccd_config.c
index fc9409a13f..91232df295 100644
--- a/common/ccd_config.c
+++ b/common/ccd_config.c
@@ -714,7 +714,7 @@ static int command_ccd_info(void)
 	ccprintf("Password: %s\n", raw_has_password() ? "set" : "none");
 	ccprintf("Flags: 0x%06x\n", raw_get_flags());
 
-	ccprintf("Capabilities: %.8h\n", config.capabilities);
+	ccprintf("Capabilities: %ph\n", HEX_BUF(config.capabilities, 8));
 	for (i = 0; i < CCD_CAP_COUNT; i++) {
 		int c = raw_get_cap(i, 0);
 
diff --git a/common/host_command.c b/common/host_command.c
index be178f7b6c..eff1fac56b 100644
--- a/common/host_command.c
+++ b/common/host_command.c
@@ -666,8 +666,9 @@ static void host_command_debug_request(struct host_cmd_handler_args *args)
 	}
 
 	if (hcdebug >= HCDEBUG_PARAMS && args->params_size)
-		CPRINTS("HC 0x%02x.%d:%.*h", args->command,
-			args->version, args->params_size, args->params);
+		CPRINTS("HC 0x%02x.%d:%ph", args->command,
+			args->version,
+			HEX_BUF(args->params, args->params_size));
 	else
 		CPRINTS("HC 0x%02x", args->command);
 }
@@ -711,8 +712,8 @@ uint16_t host_command_process(struct host_cmd_handler_args *args)
 		CPRINTS("HC 0x%02x err %d", args->command, rv);
 
 	if (hcdebug >= HCDEBUG_PARAMS && args->response_size)
-		CPRINTS("HC resp:%.*h", args->response_size,
-			args->response);
+		CPRINTS("HC resp:%ph",
+			HEX_BUF(args->response, args->response_size));
 
 	return rv;
 }
@@ -892,7 +893,8 @@ static int command_host_command(int argc, char **argv)
 	if (res != EC_RES_SUCCESS)
 		ccprintf("Command returned %d\n", res);
 	else if (args.response_size)
-		ccprintf("Response: %.*h\n", args.response_size, cmd_params);
+		ccprintf("Response: %ph\n",
+			 HEX_BUF(cmd_params, args.response_size));
 	else
 		ccprintf("Command succeeded; no response.\n");
 
diff --git a/common/i2c_master.c b/common/i2c_master.c
index ea33b6f533..091ea7f423 100644
--- a/common/i2c_master.c
+++ b/common/i2c_master.c
@@ -1145,7 +1145,7 @@ static int command_i2cxfer(int argc, char **argv)
 			      (uint8_t *)&offset, 1, data, v);
 
 		if (!rv)
-			ccprintf("Data: %.*h\n", v, data);
+			ccprintf("Data: %ph\n", HEX_BUF(data, v));
 
 	} else if (strcasecmp(argv[1], "w") == 0) {
 		/* 8-bit write */
diff --git a/common/peci.c b/common/peci.c
index b4422de05e..e0f03c95dd 100644
--- a/common/peci.c
+++ b/common/peci.c
@@ -140,7 +140,7 @@ static int peci_cmd(int argc, char **argv)
 		ccprintf("PECI transaction error\n");
 		return EC_ERROR_UNKNOWN;
 	}
-	ccprintf("PECI read data: %.*h\n", peci.r_len, r_buf);
+	ccprintf("PECI read data: %ph\n", HEX_BUF(r_buf, peci.r_len));
 	return EC_SUCCESS;
 }
 DECLARE_CONSOLE_COMMAND(peci, peci_cmd,
diff --git a/common/printf.c b/common/printf.c
index 89ee004452..777c78b471 100644
--- a/common/printf.c
+++ b/common/printf.c
@@ -5,6 +5,7 @@
 
 /* Printf-like functionality for Chrome EC */
 
+#include "console.h"
 #include "printf.h"
 #include "timer.h"
 #include "util.h"
@@ -18,6 +19,7 @@ static inline int divmod(uint64_t *n, int d)
 {
 	return uint64divmod(n, d);
 }
+
 #else /* CONFIG_DEBUG_PRINTF */
 /* if we are optimizing for size, remove the 64-bit support */
 #define NO_UINT64_SUPPORT
@@ -48,7 +50,55 @@ static int hexdigit(int c)
 #define PF_LEFT		BIT(0)  /* Left-justify */
 #define PF_PADZERO	BIT(1)  /* Pad with 0's not spaces */
 #define PF_SIGN		BIT(2)  /* Add sign (+) for a positive number */
+
+/* Deactivate the PF_64BIT flag is 64-bit support is disabled. */
+#ifdef NO_UINT64_SUPPORT
+#define PF_64BIT	0
+#else
 #define PF_64BIT	BIT(3)  /* Number is 64-bit */
+#endif
+
+/*
+ * Print the buffer as a string of bytes in hex.
+ * Returns 0 on success or an error on failure.
+ */
+static int print_hex_buffer(int (*addchar)(void *context, int c),
+			    void *context, const char *vstr, int precision,
+			    int pad_width, int flags)
+
+{
+
+	/*
+	 * Divide pad_width instead of multiplying precision to avoid overflow
+	 * error in the condition. The "/2" and "2*" can be optimized by
+	 * the compiler.
+	 */
+
+	if ((pad_width / 2) >= precision)
+		pad_width -= 2 * precision;
+	else
+		pad_width = 0;
+
+	while (pad_width > 0 && !(flags & PF_LEFT)) {
+		if (addchar(context, flags & PF_PADZERO ? '0' : ' '))
+			return EC_ERROR_OVERFLOW;
+		pad_width--;
+	}
+
+	for (; precision; precision--, vstr++) {
+		if (addchar(context, hexdigit(*vstr >> 4)) ||
+		    addchar(context, hexdigit(*vstr)))
+			return EC_ERROR_OVERFLOW;
+	}
+
+	while (pad_width > 0 && (flags & PF_LEFT)) {
+		if (addchar(context, ' '))
+			return EC_ERROR_OVERFLOW;
+		pad_width--;
+	}
+
+	return EC_SUCCESS;
+}
 
 int vfnprintf(int (*addchar)(void *context, int c), void *context,
 	      const char *format, va_list args)
@@ -162,54 +212,14 @@ int vfnprintf(int (*addchar)(void *context, int c), void *context,
 			vstr = va_arg(args, char *);
 			if (vstr == NULL)
 				vstr = "(NULL)";
-		} else if (c == 'h') {
-			/* Hex dump output */
-			vstr = va_arg(args, char *);
-
-			if (precision < 0) {
-				/* Hex dump requires precision */
-				format = error_str;
-				continue;
-			}
-
-			/*
-			 * Divide pad_width instead of multiplying
-			 * precision to avoid overflow error
-			 * in the condition.
-			 * The "/2" and "2*" can be optimized by
-			 * the compiler.
-			 */
-			if ((pad_width/2) >= precision)
-				pad_width -= 2*precision;
-			else
-				pad_width = 0;
-
-			while (pad_width > 0 && !(flags & PF_LEFT)) {
-				if (addchar(context,
-					    flags & PF_PADZERO ? '0' : ' '))
-					return EC_ERROR_OVERFLOW;
-				pad_width--;
-			}
-			for (; precision; precision--, vstr++) {
-				if (addchar(context, hexdigit(*vstr >> 4)) ||
-				    addchar(context, hexdigit(*vstr)))
-					return EC_ERROR_OVERFLOW;
-			}
-			while (pad_width > 0 && (flags & PF_LEFT)) {
-				if (addchar(context, ' '))
-					return EC_ERROR_OVERFLOW;
-				pad_width--;
-			}
 
-			continue;
 		} else {
 			int base = 10;
 #ifdef NO_UINT64_SUPPORT
 			uint32_t v;
-
-			v = va_arg(args, uint32_t);
-#else /* NO_UINT64_SUPPORT */
+#else
 			uint64_t v;
+#endif
 			int ptrspec;
 			void *ptrval;
 
@@ -223,7 +233,8 @@ int vfnprintf(int (*addchar)(void *context, int c), void *context,
 				ptrspec = *format++;
 				ptrval = va_arg(args, void *);
 				/* %pT - print a timestamp. */
-				if (ptrspec == 'T') {
+				if (ptrspec == 'T' &&
+				    !IS_ENABLED(NO_UINT64_SUPPORT)) {
 					flags |= PF_64BIT;
 					/* NULL uses the current time. */
 					if (ptrval == NULL)
@@ -239,8 +250,26 @@ int vfnprintf(int (*addchar)(void *context, int c), void *context,
 						v /= 1000;
 					}
 
+				} else if (ptrspec == 'h') {
+					/* %ph - Print a hex byte buffer. */
+					struct hex_buffer_params *hexbuf =
+						ptrval;
+					int rc;
+
+					rc = print_hex_buffer(addchar,
+							      context,
+							      hexbuf->buffer,
+							      hexbuf->size,
+							      0,
+							      0);
+
+					if (rc != EC_SUCCESS)
+						return rc;
+
+					continue;
+
 				} else if (ptrspec == 'P') {
-					/* Print a raw pointer. */
+					/* %pP - Print a raw pointer. */
 					v = (unsigned long)ptrval;
 					if (sizeof(unsigned long) ==
 					    sizeof(uint64_t))
@@ -255,7 +284,6 @@ int vfnprintf(int (*addchar)(void *context, int c), void *context,
 			} else {
 				v = va_arg(args, uint32_t);
 			}
-#endif
 
 			switch (c) {
 #ifdef CONFIG_PRINTF_LEGACY_LI_FORMAT
diff --git a/common/spi_commands.c b/common/spi_commands.c
index 9fdc721d40..1a70a5be82 100644
--- a/common/spi_commands.c
+++ b/common/spi_commands.c
@@ -46,7 +46,7 @@ static int command_spixfer(int argc, char **argv)
 		rv = spi_transaction(&spi_devices[dev_id], &cmd, 1, data, v);
 
 		if (!rv)
-			ccprintf("Data: %.*h\n", v, data);
+			ccprintf("Data: %ph\n", HEX_BUF(data, v));
 
 	} else if (strcasecmp(argv[1], "w") == 0) {
 		/* 8-bit write */
diff --git a/common/vboot_hash.c b/common/vboot_hash.c
index 4d12af7c7b..0642e09e3c 100644
--- a/common/vboot_hash.c
+++ b/common/vboot_hash.c
@@ -141,7 +141,7 @@ static void vboot_hash_next_chunk(void)
 	if (curr_pos >= data_size) {
 		/* Store the final hash */
 		hash = SHA256_final(&ctx);
-		CPRINTS("hash done %.*h", SHA256_PRINT_SIZE, hash);
+		CPRINTS("hash done %ph", HEX_BUF(hash, SHA256_PRINT_SIZE));
 
 		in_progress = 0;
 
@@ -331,7 +331,7 @@ static int command_hash(int argc, char **argv)
 		else if (in_progress)
 			ccprintf("(in progress)\n");
 		else if (hash)
-			ccprintf("%.*h\n", SHA256_DIGEST_SIZE, hash);
+			ccprintf("%ph\n", HEX_BUF(hash, SHA256_DIGEST_SIZE));
 		else
 			ccprintf("(invalid)\n");
 
diff --git a/driver/touchpad_st.c b/driver/touchpad_st.c
index 5fbeeb45ea..d3381bd92c 100644
--- a/driver/touchpad_st.c
+++ b/driver/touchpad_st.c
@@ -600,15 +600,16 @@ static void dump_memory(void)
 				(uint8_t *)&rx_buf, rx_len);
 
 		for (i = 0; i < rx_len - ST_TP_DUMMY_BYTE; i += 32) {
-			CPRINTF("%.4h %.4h %.4h %.4h %.4h %.4h %.4h %.4h\n",
-				rx_buf.bytes + i + 4 * 0,
-				rx_buf.bytes + i + 4 * 1,
-				rx_buf.bytes + i + 4 * 2,
-				rx_buf.bytes + i + 4 * 3,
-				rx_buf.bytes + i + 4 * 4,
-				rx_buf.bytes + i + 4 * 5,
-				rx_buf.bytes + i + 4 * 6,
-				rx_buf.bytes + i + 4 * 7);
+			CPRINTF("%ph %ph %ph %ph "
+				"%ph %ph %ph %ph\n",
+				HEX_BUF(rx_buf.bytes + i + 4 * 0, 4),
+				HEX_BUF(rx_buf.bytes + i + 4 * 1, 4),
+				HEX_BUF(rx_buf.bytes + i + 4 * 2, 4),
+				HEX_BUF(rx_buf.bytes + i + 4 * 3, 4),
+				HEX_BUF(rx_buf.bytes + i + 4 * 4, 4),
+				HEX_BUF(rx_buf.bytes + i + 4 * 5, 4),
+				HEX_BUF(rx_buf.bytes + i + 4 * 6, 4),
+				HEX_BUF(rx_buf.bytes + i + 4 * 7, 4));
 			msleep(8);
 		}
 	}
@@ -1264,7 +1265,7 @@ int touchpad_debug(const uint8_t *param, unsigned int param_size,
 		*data_size = 8;
 		st_tp_read_host_buffer_header();
 		memcpy(buf, rx_buf.bytes, *data_size);
-		CPRINTS("header: %.*h", *data_size, buf);
+		CPRINTS("header: %ph", HEX_BUF(buf, *data_size));
 		return EC_SUCCESS;
 	case ST_TP_DEBUG_CMD_READ_EVENTS:
 		num_events = st_tp_read_all_events(0);
diff --git a/fuzz/host_command_fuzz.c b/fuzz/host_command_fuzz.c
index 9ac7955aed..5d490bc192 100644
--- a/fuzz/host_command_fuzz.c
+++ b/fuzz/host_command_fuzz.c
@@ -113,8 +113,8 @@ static int hostcmd_fill(const uint8_t *data, size_t size)
 	 * issues.
 	 */
 	if (first) {
-		ccprintf("Request: cmd=%04x data=%.*h\n",
-			req->command, req_size, req_buf);
+		ccprintf("Request: cmd=%04x data=%ph\n",
+			req->command, HEX_BUF(req_buf, req_size));
 		first = 0;
 	}
 
diff --git a/include/console.h b/include/console.h
index 73e9d9094c..dc15e5b6d3 100644
--- a/include/console.h
+++ b/include/console.h
@@ -10,6 +10,22 @@
 
 #include "common.h"
 
+/*
+ * The EC code base has been using %h to print a hex buffer. Encode the
+ * parameters to do that in a pointer to a structure that's passed as the
+ * printf argument. This is done rather than something like %.123ph because
+ * the C standard doesn't allow flags, precision, and field width on %p.
+ */
+struct hex_buffer_params {
+	const void *buffer;
+	uint16_t size;
+};
+
+#define HEX_BUF(_buffer, _size) (&(const struct hex_buffer_params){ \
+	.buffer = (_buffer), \
+	.size = (_size) \
+})
+
 #define PRINTF_TIMESTAMP_NOW NULL
 
 /* Console command; used by DECLARE_CONSOLE_COMMAND macro. */
diff --git a/include/printf.h b/include/printf.h
index c55c8f7d2b..6e245a3f2a 100644
--- a/include/printf.h
+++ b/include/printf.h
@@ -40,10 +40,6 @@
  * Type may be:
  *   - 'c' - character
  *   - 's' - null-terminated ASCII string
- *   - 'h' - binary data, print as hex; precision is length of data in bytes.
- *           So "%.8h" prints 8 bytes of binary data
- *   - 'pP'- raw pointer. %p followed by another character represents a %p
- *           extension.
  *   - 'd' - signed integer
  *   - 'i' - signed integer if CONFIG_PRINTF_LEGACY_LI_FORMAT is set (ignore l)
  *   - 'u' - unsigned integer
@@ -52,6 +48,9 @@
  *   - 'b' - unsigned integer, print as binary
  *
  * Special format codes:
+ *   - '%ph' - binary data, print as hex; Use HEX_BUF(buffer, size) to encode
+ *             parameters.
+ *   - '%pP' - raw pointer.
  *   - "%pT" - current time in seconds - interpreted as "%.6T" for precision.
  *           Supply PRINTF_TIMESTAMP_NOW to use the current time, or supply a
  *           pointer to a 64-bit timestamp to print.
diff --git a/test/printf.c b/test/printf.c
index cf20be7b31..c758d9bccb 100644
--- a/test/printf.c
+++ b/test/printf.c
@@ -253,11 +253,9 @@ test_static int test_vsnprintf_hexdump(void)
 {
 	const char bytes[] = {0x00, 0x5E};
 
-	T(expect_success(err_str,     "%h",      bytes));
-	T(expect_success("005e",      "%.*h",    2, bytes));
-	T(expect_success("",          "%.*h",    0, bytes));
-	T(expect_success(" 005e",     "%5.*h",   2, bytes));
-	T(expect_success("00",        "%0*.*h",  2, 0, bytes));
+	T(expect_success("005e",      "%ph",      HEX_BUF(bytes, 2)));
+	T(expect_success("",          "%ph",      HEX_BUF(bytes, 0)));
+	T(expect_success("00",        "%ph",      HEX_BUF(bytes, 1)));
 	return EC_SUCCESS;
 }