https://www.xilinx.com/html_docs/xilinx2017_3/SDK_Doc/xsct/intro/xsct_introduction.html
Graphical development environments such as the Xilinx® Software Development Kit (Xilinx SDK) are useful for getting up to speed on development for a new processor architecture. It helps to abstract away and group most of the common functions into logical wizards that even the novice can use. However, scriptability of a tool is also essential for providing the flexibility to extend what is done with that tool. It is particularly useful when developing regression tests that will be run nightly or running a set of commands that are used often by the developer.

Xilinx Software Command-line Tool (XSCT) is an interactive and scriptable command-line interface to Xilinx SDK. As with other Xilinx tools, the scripting language for XSCT is based on Tools Command Language (Tcl). You can run XSCT commands interactively or script the commands for automation. XSCT supports the following actions:
Create hardware, board support packages (BSPs), and application projects
Manage repositories
Set toolchain preferences
Configure and build BSPs/applications
Download and run applications on hardware targets
Create and flash boot images by running Bootgen and program_flash tools.
This reference guide is intended to provide information you need to develop scripts for software development and debug targeting the Xilinx family of processors.

As you read the document you will notice usage of some abbreviations for various products produced by Xilinx. For example:
Use of ps7 in the source code implies that these files are targeting the Zynq® - 7000 AP SoC family of products, and specifically the dual-core Cortex™ ARM® A9 processors in the SoC.
Use of psu in the source code implies that this code is targeting a Zynq UltraScale+™ MPSoC device, which contains a Cortex Quad-core ARM A53, dual-core ARM R5, ARM Mali 400 GPU, and a MicroBlaze™ processor based platform management unit (PMU).
Hardware definition files (HDF) are used to transfer the information about the hardware system that includes a processor to the embedded software development tools such as Xilinx SDK (XSDK) and Xilinx Software Command-Line Tools (XSCT). It includes information about which peripherals are instantiated, clocks, memory interfaces, and memory maps.
Microprocessor Software Specification (MSS) files are used to store information about the BSP. They contain OS information for the BSP, software drivers associated with each peripheral of the hardware design, STDIO settings, and compiler flags like optimization and debug information level

google翻譯：
Xilinx軟體命令列工具（XSCT）
諸如Xilinx®軟體開發套件（Xilinx SDK）等圖形開發環境對於快速開發新的處理器架構非常有用。它有助於抽象並將大多數常見功能組合成邏輯嚮導，即使是初學者也可以使用。但是，工具的可程式設計性對於提供擴充套件該工具的靈活性也是必不可少的。在開發將每晚執行的迴歸測試或執行開發人員經常使用的一組命令時，它尤其有用。

Xilinx軟體命令列工具（XSCT）是Xilinx SDK的互動式指令碼命令列介面。與其他Xilinx工具一樣，XSCT的指令碼語言基於工具命令語言（Tcl）。您可以互動方式執行XSCT命令，也可以編寫自動化命令指令碼。XSCT支援以下操作：
建立硬體，板級支援包（BSP）和應用程式專案
管理儲存庫
設定工具鏈首選項
配置和構建BSP /應用程式
在硬體目標上下載並執行應用程式
通過執行Bootgen和program_flash工具建立和重新整理啟動映像。
本參考指南旨在提供開發針對Xilinx系列處理器的軟體開發和除錯指令碼所需的資訊。

在閱讀本文件時，您會注意到Xilinx生產的各種產品的縮寫。例如：
使用ps7原始碼意味著這些檔案針對Zynq® - 7000 AP SoC系列產品，並在SoC特別是雙核Cortex™ARM®A9處理器。
使用的psu原始碼中的指的是此程式碼的目標是一個ZYNQ的UltraScale +™片上多核裝置，其包含的Cortex四核ARM A53，雙核ARM R5，ARM馬裡400 GPU，和一個的MicroBlaze™處理器基於平臺管理單元（ PMU）。
硬體定義檔案（HDF）用於將包含處理器的硬體系統的資訊傳輸到嵌入式軟體開發工具，如Xilinx SDK（XSDK）和Xilinx軟體命令列工具（XSCT）。它包括有關例項化哪些外設，時鐘，儲存器介面和儲存器對映的資訊。
微處理器軟體規範（MSS）檔案用於儲存有關BSP的資訊。它們包含BSP的OS資訊，與硬體設計的每個外圍裝置相關的軟體驅動程式，STDIO設定以及優化和除錯資訊級別等編譯器標誌。