From patchwork Tue Feb 20 11:05:22 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 128866 Delivered-To: patch@linaro.org Received: by 10.46.124.24 with SMTP id x24csp4509397ljc; Tue, 20 Feb 2018 03:05:54 -0800 (PST) X-Google-Smtp-Source: AH8x225KLzuUGhzujd58HInAnnTCTtrWAjBm+UVMXC/LRVXjlYcTnbcTl9y0aV889ms899DF4CER X-Received: by 10.99.102.1 with SMTP id a1mr14801798pgc.452.1519124754123; Tue, 20 Feb 2018 03:05:54 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1519124754; cv=none; d=google.com; s=arc-20160816; b=U2+RRPXFRTyireinMUBMBZsDNcqG0ZGP+AcAPg215VL+ZgkMrqEsP4XPo66Ym2mWWV Z30oPsKN/jzFoGU0gW6/vPuLLvDRANZBYN/NN3rCkB9wijmfn+jm5tUSNToaLj3XIqos gkZPcaGdsotwRjJgB8XMGoEzrbTgVnXr+6+1Zq33IUxqzjEkkY37Ox2dYureYLlM+pRV X6dfQN3A9Ev0EJC/TSoQdki5kyn9GBSBT6WKeUdqbGUXcuzzoR/NEYT4oK6syplNEM+7 1cLVCS0uvI07EOay9U830pUWHorgO++OqWh6niXY3W4PyjA51G/HjqWkbX7cXhZP/rDx ErcA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:content-transfer-encoding:mime-version:cc :list-subscribe:list-help:list-post:list-archive:list-unsubscribe :list-id:precedence:subject:references:in-reply-to:message-id:date :to:from:dkim-signature:delivered-to:arc-authentication-results; bh=UyU+cTGwHP+Ul93l1oiW8y5U/VQtoe1Ap496FzjHyuE=; b=SfWrc6hTzo2k7Xw/+lOqnpryGouQCNRhLgupf8zZbZqUSVAzTyRbazmPPE+n9GVvJ7 TwR0ThX77bJaoeTjsaVUX7sOuaZH7ex/VTa6gK4DFPyfjQax5wWL98oWKDynkb8BoQfP eVQANCv6PXL9iBVA0Dhxp42U6kjm5UrTb4PJmaYiVxYu6Pqx6ZBoBlIvmAbKUa1n4GtE D6s21w0xavN/dwQWIa4zd3SDfktueucKe/e5wzQa9U9oDla846TquKRXWbGHZYsgD61J St6vMVuv5XWqJaU3I5i7no1kc5xzZ4wqCuOERBcOdY6DzTdF2Lany2OtHCSNYGOftkMp MrRA== ARC-Authentication-Results: i=1; mx.google.com; dkim=neutral (body hash did not verify) header.i=@linaro.org header.s=google header.b=d2+MG53g; spf=pass (google.com: best guess record for domain of edk2-devel-bounces@lists.01.org designates 2001:19d0:306:5::1 as permitted sender) smtp.mailfrom=edk2-devel-bounces@lists.01.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from ml01.01.org (ml01.01.org. [2001:19d0:306:5::1]) by mx.google.com with ESMTPS id g128si6606546pgc.574.2018.02.20.03.05.53 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 20 Feb 2018 03:05:54 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of edk2-devel-bounces@lists.01.org designates 2001:19d0:306:5::1 as permitted sender) client-ip=2001:19d0:306:5::1; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@linaro.org header.s=google header.b=d2+MG53g; spf=pass (google.com: best guess record for domain of edk2-devel-bounces@lists.01.org designates 2001:19d0:306:5::1 as permitted sender) smtp.mailfrom=edk2-devel-bounces@lists.01.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 39B4C223C1785; Tue, 20 Feb 2018 02:59:55 -0800 (PST) X-Original-To: edk2-devel@lists.01.org Delivered-To: edk2-devel@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=2a00:1450:400c:c0c::243; helo=mail-wr0-x243.google.com; envelope-from=ard.biesheuvel@linaro.org; receiver=edk2-devel@lists.01.org Received: from mail-wr0-x243.google.com (mail-wr0-x243.google.com [IPv6:2a00:1450:400c:c0c::243]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 1C5D5223C1769 for ; Tue, 20 Feb 2018 02:59:51 -0800 (PST) Received: by mail-wr0-x243.google.com with SMTP id 34so13122780wre.13 for ; Tue, 20 Feb 2018 03:05:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=hbbmCOe2BcUU3NIfixTwhEpEH7g+2mjs1eWBBZWBKbM=; b=d2+MG53gbAsnd4g5kM9hsNN7qreGqZgXkR5riYUf2lY6AEHD5jfv7eh5RdoUjAzega 1f7l3M/kgBghIPJAriPVFPs9L5wW/VzBbwqxPJCe0sY1HVsl/KL7d2BxtYKZQhjZVlSG qt9tegUxTckYzEYZl25yyn9QFAAh6apobCuis= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=hbbmCOe2BcUU3NIfixTwhEpEH7g+2mjs1eWBBZWBKbM=; b=WH1AB1/kjCNrktAVezpLymC13KLAQ9IfZgHYC2pIolgaCq4G53OR5ppdGshKDMRsQ5 lvyZeCoog4XbqtZWGXUU95B0vDxYtjEhMwlGt0cUaK1kgIsQb6eTxBrXh3My7ZCvFwvH FySSoYl4ANjk7KNL8GG/VYtebc64Kf9JysJqr6BEmOif4hx+B3qj68e6jpp6lVdxU7AM FCwext0Lr5dnBwgCwzLJINWcn6UMNV90I+fSy5eHVQXqGOAthd1rygcU41xHCETHVDC5 MwnlEaDVh3pwsiKmvV7baOxGs3hae24PAcZiNkl9L9+OISH4uDti4giRLq6L3MU5YcEs v+oQ== X-Gm-Message-State: APf1xPDmiTYSp11Z9Z7W78hEqBb9jB7jbxfJd2rNm2V9tb0gK0XcQ0Om dR5niJWni2RR0TTQWIX+3FoUpFPTMBk= X-Received: by 10.28.88.70 with SMTP id m67mr14954713wmb.134.1519124748263; Tue, 20 Feb 2018 03:05:48 -0800 (PST) Received: from localhost.localdomain ([105.149.187.179]) by smtp.gmail.com with ESMTPSA id u198sm7417343wmu.44.2018.02.20.03.05.46 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 20 Feb 2018 03:05:47 -0800 (PST) From: Ard Biesheuvel To: edk2-devel@lists.01.org Date: Tue, 20 Feb 2018 11:05:22 +0000 Message-Id: <20180220110524.9050-2-ard.biesheuvel@linaro.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180220110524.9050-1-ard.biesheuvel@linaro.org> References: <20180220110524.9050-1-ard.biesheuvel@linaro.org> Subject: [edk2] [PATCH 1/3] MdePkg: introduce DxeRuntimeDebugLibSerialPort X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: ruiyu.ni@intel.com, Ard Biesheuvel , afish@apple.com, leif.lindholm@linaro.org, liming.gao@intel.com, michael.d.kinney@intel.com, lersek@redhat.com, star.zeng@intel.com MIME-Version: 1.0 Errors-To: edk2-devel-bounces@lists.01.org Sender: "edk2-devel" Introduce a variant of BaseDebugLibSerialPort that behaves correctly wrt to use of the serial port after ExitBootServices(). Also, it uses fixed PCDs for all the parameterized values so that no calls into PcdLib are made at runtime. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ard Biesheuvel --- MdePkg/Library/DxeRuntimeDebugLibSerialPort/DebugLib.c | 342 ++++++++++++++++++++ MdePkg/Library/DxeRuntimeDebugLibSerialPort/DxeRuntimeDebugLibSerialPort.inf | 46 +++ MdePkg/Library/DxeRuntimeDebugLibSerialPort/DxeRuntimeDebugLibSerialPort.uni | 21 ++ 3 files changed, 409 insertions(+) -- 2.11.0 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel diff --git a/MdePkg/Library/DxeRuntimeDebugLibSerialPort/DebugLib.c b/MdePkg/Library/DxeRuntimeDebugLibSerialPort/DebugLib.c new file mode 100644 index 000000000000..d18267d91322 --- /dev/null +++ b/MdePkg/Library/DxeRuntimeDebugLibSerialPort/DebugLib.c @@ -0,0 +1,342 @@ +/** @file + DXE runtime Debug library instance based on Serial Port library. + It uses PrintLib to send debug messages to serial port device. + + NOTE: If the Serial Port library enables hardware flow control, then a call + to DebugPrint() or DebugAssert() may hang if writes to the serial port are + being blocked. This may occur if a key(s) are pressed in a terminal emulator + used to monitor the DEBUG() and ASSERT() messages. + + Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.
+ Copyright (c) 2018, Linaro, Ltd. All rights reserved.
+ + This program and the accompanying materials + are licensed and made available under the terms and conditions of the BSD License + which accompanies this distribution. The full text of the license may be found at + http://opensource.org/licenses/bsd-license.php. + + THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, + WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. + +**/ + +#include +#include +#include +#include +#include +#include +#include +#include + +STATIC EFI_EVENT mEfiExitBootServicesEvent; +STATIC BOOLEAN mEfiAtRuntime; + +// +// Define the maximum debug and assert message length that this library supports +// +#define MAX_DEBUG_MESSAGE_LENGTH 0x100 + +/** + Set AtRuntime flag as TRUE after ExitBootServices. + + @param[in] Event The Event that is being processed. + @param[in] Context The Event Context. + +**/ +STATIC +VOID +EFIAPI +RuntimeLibExitBootServicesEvent ( + IN EFI_EVENT Event, + IN VOID *Context + ) +{ + mEfiAtRuntime = TRUE; +} + +/** + The constructor function initialize the Serial Port Library + + @retval EFI_SUCCESS The constructor always returns RETURN_SUCCESS. + +**/ +EFI_STATUS +EFIAPI +DxeRuntimeDebugLibSerialPortConstructor ( + IN EFI_HANDLE ImageHandle, + IN EFI_SYSTEM_TABLE *SystemTable + ) +{ + EFI_STATUS Status; + + Status = SerialPortInitialize (); + if (EFI_ERROR (Status)) { + return Status; + } + + return SystemTable->BootServices->CreateEventEx ( + EVT_NOTIFY_SIGNAL, + TPL_NOTIFY, + RuntimeLibExitBootServicesEvent, + NULL, + &gEfiEventExitBootServicesGuid, + &mEfiExitBootServicesEvent); +} + +/** + Prints a debug message to the debug output device if the specified error level + is enabled. + + If any bit in ErrorLevel is also set in DebugPrintErrorLevelLib function + GetDebugPrintErrorLevel (), then print the message specified by Format and the + associated variable argument list to the debug output device. + + If Format is NULL, then ASSERT(). + + @param ErrorLevel The error level of the debug message. + @param Format Format string for the debug message to print. + @param ... Variable argument list whose contents are accessed + based on the format string specified by Format. + +**/ +VOID +EFIAPI +DebugPrint ( + IN UINTN ErrorLevel, + IN CONST CHAR8 *Format, + ... + ) +{ + CHAR8 Buffer[MAX_DEBUG_MESSAGE_LENGTH]; + VA_LIST Marker; + + if (mEfiAtRuntime) { + return; + } + + // + // Check driver debug mask value and global mask + // + if ((ErrorLevel & GetDebugPrintErrorLevel ()) == 0) { + return; + } + + // + // Convert the DEBUG() message to an ASCII String + // + VA_START (Marker, Format); + AsciiVSPrint (Buffer, sizeof (Buffer), Format, Marker); + VA_END (Marker); + + // + // Send the print string to a Serial Port + // + SerialPortWrite ((UINT8 *)Buffer, AsciiStrLen (Buffer)); +} + + +/** + Prints an assert message containing a filename, line number, and description. + This may be followed by a breakpoint or a dead loop. + + Print a message of the form "ASSERT (): \n" + to the debug output device. If DEBUG_PROPERTY_ASSERT_BREAKPOINT_ENABLED bit + of PcdDebugProperyMask is set then CpuBreakpoint() is called. Otherwise, if + DEBUG_PROPERTY_ASSERT_DEADLOOP_ENABLED bit of PcdDebugProperyMask is set then + CpuDeadLoop() is called. If neither of these bits are set, then this function + returns immediately after the message is printed to the debug output device. + DebugAssert() must actively prevent recursion. If DebugAssert() is called + while processing another DebugAssert(), then DebugAssert() must return + immediately. + + If FileName is NULL, then a string of "(NULL) Filename" is printed. + If Description is NULL, then a string of "(NULL) Description" is + printed. + + @param FileName The pointer to the name of the source file that generated + the assert condition. + @param LineNumber The line number in the source file that generated the + assert condition + @param Description The pointer to the description of the assert condition. + +**/ +VOID +EFIAPI +DebugAssert ( + IN CONST CHAR8 *FileName, + IN UINTN LineNumber, + IN CONST CHAR8 *Description + ) +{ + CHAR8 Buffer[MAX_DEBUG_MESSAGE_LENGTH]; + + if (!mEfiAtRuntime) { + // + // Generate the ASSERT() message in Ascii format + // + AsciiSPrint (Buffer, sizeof (Buffer), "ASSERT [%a] %a(%d): %a\n", + gEfiCallerBaseName, FileName, LineNumber, Description); + + // + // Send the print string to the Console Output device + // + SerialPortWrite ((UINT8 *)Buffer, AsciiStrLen (Buffer)); + } + + // + // Generate a Breakpoint, DeadLoop, or NOP based on PCD settings + // + if ((FixedPcdGet8 (PcdDebugPropertyMask) & + DEBUG_PROPERTY_ASSERT_BREAKPOINT_ENABLED) != 0) { + CpuBreakpoint (); + } else if ((FixedPcdGet8 (PcdDebugPropertyMask) & + DEBUG_PROPERTY_ASSERT_DEADLOOP_ENABLED) != 0) { + CpuDeadLoop (); + } +} + + +/** + Fills a target buffer with PcdDebugClearMemoryValue, and returns the target + buffer. + + This function fills Length bytes of Buffer with the value specified by + PcdDebugClearMemoryValue, and returns Buffer. + + If Buffer is NULL, then ASSERT(). + If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT(). + + @param Buffer The pointer to the target buffer to be filled with + PcdDebugClearMemoryValue. + @param Length The number of bytes in Buffer to fill with + PcdDebugClearMemoryValue. + + @return Buffer The pointer to the target buffer filled with + PcdDebugClearMemoryValue. + +**/ +VOID * +EFIAPI +DebugClearMemory ( + OUT VOID *Buffer, + IN UINTN Length + ) +{ + // + // SetMem() checks for the the ASSERT() condition on Length and returns Buffer + // + return SetMem (Buffer, Length, FixedPcdGet8 (PcdDebugClearMemoryValue)); +} + + +/** + Returns TRUE if ASSERT() macros are enabled. + + This function returns TRUE if the DEBUG_PROPERTY_DEBUG_ASSERT_ENABLED bit of + PcdDebugProperyMask is set. Otherwise FALSE is returned. + + @retval TRUE The DEBUG_PROPERTY_DEBUG_ASSERT_ENABLED bit of + PcdDebugProperyMask is set. + @retval FALSE The DEBUG_PROPERTY_DEBUG_ASSERT_ENABLED bit of + PcdDebugProperyMask is clear. + +**/ +BOOLEAN +EFIAPI +DebugAssertEnabled ( + VOID + ) +{ + return (FixedPcdGet8 (PcdDebugPropertyMask) & + DEBUG_PROPERTY_DEBUG_ASSERT_ENABLED) != 0; +} + + +/** + Returns TRUE if DEBUG() macros are enabled. + + This function returns TRUE if the DEBUG_PROPERTY_DEBUG_PRINT_ENABLED bit of + PcdDebugProperyMask is set. Otherwise FALSE is returned. + + @retval TRUE The DEBUG_PROPERTY_DEBUG_PRINT_ENABLED bit of + PcdDebugProperyMask is set. + @retval FALSE The DEBUG_PROPERTY_DEBUG_PRINT_ENABLED bit of + PcdDebugProperyMask is clear. + +**/ +BOOLEAN +EFIAPI +DebugPrintEnabled ( + VOID + ) +{ + return (FixedPcdGet8 (PcdDebugPropertyMask) & + DEBUG_PROPERTY_DEBUG_PRINT_ENABLED) != 0; +} + + +/** + Returns TRUE if DEBUG_CODE() macros are enabled. + + This function returns TRUE if the DEBUG_PROPERTY_DEBUG_CODE_ENABLED bit of + PcdDebugProperyMask is set. Otherwise FALSE is returned. + + @retval TRUE The DEBUG_PROPERTY_DEBUG_CODE_ENABLED bit of + PcdDebugProperyMask is set. + @retval FALSE The DEBUG_PROPERTY_DEBUG_CODE_ENABLED bit of + PcdDebugProperyMask is clear. + +**/ +BOOLEAN +EFIAPI +DebugCodeEnabled ( + VOID + ) +{ + return (FixedPcdGet8 (PcdDebugPropertyMask) & + DEBUG_PROPERTY_DEBUG_CODE_ENABLED) != 0; +} + + +/** + Returns TRUE if DEBUG_CLEAR_MEMORY() macro is enabled. + + This function returns TRUE if the DEBUG_PROPERTY_CLEAR_MEMORY_ENABLED bit of + PcdDebugProperyMask is set. Otherwise FALSE is returned. + + @retval TRUE The DEBUG_PROPERTY_CLEAR_MEMORY_ENABLED bit of + PcdDebugProperyMask is set. + @retval FALSE The DEBUG_PROPERTY_CLEAR_MEMORY_ENABLED bit of + PcdDebugProperyMask is clear. + +**/ +BOOLEAN +EFIAPI +DebugClearMemoryEnabled ( + VOID + ) +{ + return (FixedPcdGet8 (PcdDebugPropertyMask) & + DEBUG_PROPERTY_CLEAR_MEMORY_ENABLED) != 0; +} + +/** + Returns TRUE if any one of the bit is set both in ErrorLevel and + PcdFixedDebugPrintErrorLevel. + + This function compares the bit mask of ErrorLevel and + PcdFixedDebugPrintErrorLevel. + + @retval TRUE Current ErrorLevel is supported. + @retval FALSE Current ErrorLevel is not supported. + +**/ +BOOLEAN +EFIAPI +DebugPrintLevelEnabled ( + IN CONST UINTN ErrorLevel + ) +{ + return (ErrorLevel & FixedPcdGet32 (PcdFixedDebugPrintErrorLevel)) != 0; +} diff --git a/MdePkg/Library/DxeRuntimeDebugLibSerialPort/DxeRuntimeDebugLibSerialPort.inf b/MdePkg/Library/DxeRuntimeDebugLibSerialPort/DxeRuntimeDebugLibSerialPort.inf new file mode 100644 index 000000000000..9f300f4f1b12 --- /dev/null +++ b/MdePkg/Library/DxeRuntimeDebugLibSerialPort/DxeRuntimeDebugLibSerialPort.inf @@ -0,0 +1,46 @@ +## @file +# +# Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.
+# Copyright (c) 2018, Linaro, Ltd. All rights reserved.
+# +# This program and the accompanying materials +# are licensed and made available under the terms and conditions of the BSD License +# which accompanies this distribution. The full text of the license may be found at +# http://opensource.org/licenses/bsd-license.php. +# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, +# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. +# +# +## + +[Defines] + INF_VERSION = 0x00010005 + BASE_NAME = DxeRuntimeDebugLibSerialPort + MODULE_UNI_FILE = DxeRuntimeDebugLibSerialPort.uni + FILE_GUID = 9D914E2F-7CCB-41DB-8E74-9AFF8F3BBFBF + MODULE_TYPE = DXE_RUNTIME_DRIVER + VERSION_STRING = 1.0 + LIBRARY_CLASS = DebugLib + CONSTRUCTOR = DxeRuntimeDebugLibSerialPortConstructor + +[Sources] + DebugLib.c + +[Packages] + MdePkg/MdePkg.dec + +[LibraryClasses] + BaseLib + BaseMemoryLib + DebugPrintErrorLevelLib + PcdLib + PrintLib + SerialPortLib + +[Guids] + gEfiEventExitBootServicesGuid + +[FixedPcd] + gEfiMdePkgTokenSpaceGuid.PcdDebugClearMemoryValue ## SOMETIMES_CONSUMES + gEfiMdePkgTokenSpaceGuid.PcdDebugPropertyMask ## CONSUMES + gEfiMdePkgTokenSpaceGuid.PcdFixedDebugPrintErrorLevel ## CONSUMES diff --git a/MdePkg/Library/DxeRuntimeDebugLibSerialPort/DxeRuntimeDebugLibSerialPort.uni b/MdePkg/Library/DxeRuntimeDebugLibSerialPort/DxeRuntimeDebugLibSerialPort.uni new file mode 100644 index 000000000000..cd65515c4177 --- /dev/null +++ b/MdePkg/Library/DxeRuntimeDebugLibSerialPort/DxeRuntimeDebugLibSerialPort.uni @@ -0,0 +1,21 @@ +// /** @file +// Instance of Debug Library based on Serial Port Library. +// +// It uses Print Library to produce formatted output strings to seiral port device. +// +// Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.
+// +// This program and the accompanying materials +// are licensed and made available under the terms and conditions of the BSD License +// which accompanies this distribution. The full text of the license may be found at +// http://opensource.org/licenses/bsd-license.php. +// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, +// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. +// +// **/ + + +#string STR_MODULE_ABSTRACT #language en-US "Instance of Debug Library based on Serial Port Library" + +#string STR_MODULE_DESCRIPTION #language en-US "It uses Print Library to produce formatted output strings to a serial port device." +