“Cross-compile with OpenSTLinux SDK”的版本间的差异
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2020年11月2日 (一) 14:07的最新版本
目录
Article purpose
The pieces of software delivered as source code within the OpenSTLinux Developer Package (for example the Linux kernel) can be modified. External out-of-tree Linux kernel modules, and pieces of applicative software (for example Linux applications) can also be developed thanks to this Developer Package, and loaded onto the board.
The build of all these pieces of software by means of the SDK for OpenSTLinux distribution, and the deployment on-target of the resulting images is explained below.
To use the cross-compilation efficiently with the OpenSTLinux SDK, it is recommended that you read the Developer Package article relative to the Series of your STM32 microprocessor: Category:Developer Package |
Modifying the Linux kernel
Prerequisites:
The <Linux kernel installation directory>/README.HOW_TO.txt helper file gives the commands to:
☐ configure the Linux kernel
☐ cross-compile the Linux kernel
☐ deploy the Linux kernel (that is, update the software on board)
You can refer to the following simple examples:
Adding external out-of-tree Linux kernel modules
Prerequisites:
Most device drivers (or modules) in the Linux kernel can be compiled either into the kernel itself (built-in, or internal module) or as Loadable Kernel Modules (LKMs, or external modules) that need to be placed in the root file system under the /lib/modules directory. An external module can be in-tree (in the kernel tree structure), or out-of-tree (outside the kernel tree structure).
External Linux kernel modules are compiled taking reference to a Linux kernel source tree and a Linux kernel configuration file (.config).
Thus, a makefile for an external Linux kernel module points to the Linux kernel directory that contains the source code and the configuration file, with the "-C <Linux kernel path>" option.
This makefile also points to the directory that contains the source file(s) of the Linux kernel module to compile, with the "M=<Linux kernel module path>" option.
A generic makefile for an external out-of-tree Linux kernel module looks like the following:
# Makefile for external out-of-tree Linux kernel module # Object file(s) to be built obj-m := <module source file(s)>.o # Path to the directory that contains the Linux kernel source code # and the configuration file (.config) KERNEL_DIR ?= <Linux kernel path> # Path to the directory that contains the generated objects DESTDIR ?= <Linux kernel installation directory> # Path to the directory that contains the source file(s) to compile PWD := $(shell pwd) default: $(MAKE) -C $(KERNEL_DIR) M=$(PWD) modules install: $(MAKE) -C $(KERNEL_DIR) M=$(PWD) INSTALL_MOD_PATH=$(DESTDIR) modules_install clean: $(MAKE) -C $(KERNEL_DIR) M=$(PWD) clean
Such module is then cross-compiled with the following commands:
$ make clean $ make $ make install
You can refer to the following simple example:
Adding Linux user space applications
Prerequisites:
- the SDK is installed
- the SDK is started up
Once a suitable cross-toolchain (OpenSTLinux SDK) is installed, it is easy to develop a project outside of the OpenEmbedded build system.
There are different ways to use the SDK toolchain directly, among which Makefile and Autotools.
Whatever the method, it relies on:
- the sysroot that is associated with the cross-toolchain, and that contains the header files and libraries needed for generating binaries (see target sysroot)
- the environment variables created by the SDK environment setup script (see SDK startup)
You can refer to the following simple example:
Modifying the U-Boot
Prerequisites:
- the SDK is installed
- the SDK is started up
- the U-Boot is installed
The <U-Boot installation directory>/README.HOW_TO.txt helper file gives the commands to:
☐ cross-compile the U-Boot
☐ deploy the U-Boot (that is, update the software on board)
You can refer to the following simple example:
Modifying the TF-A
Prerequisites:
- the SDK is installed
- the SDK is started up
- the TF-A is installed
The <TF-A installation directory>/README.HOW_TO.txt helper file gives the commands to:
☐ cross-compile the TF-A
☐ deploy the TF-A (that is, update the software on board)
You can refer to the following simple example:
Modifying the OP-TEE
Prerequisites:
- the SDK is installed
- the SDK is started up
- the OP-TEE is installed
The <OP-TEE installation directory>/README.HOW_TO.txt helper file gives the commands to:
☐ cross-compile the OP-TEE
☐ deploy the OP-TEE (that is, update the software on board)
<securetransclude src="ProtectedTemplate:ReviewsComments" params="YCO 15-Feb-19 : link missing "Modification of the OP-TEE"<br>
There is no link because the page "How_to_cross-compile_with_the_Developer_Package" doesn't contain a paragraph for TEE, <br> SO THIS PARAGRAH "Modifying the OP-TEE" is not useful, it gives no more informations.<br> The paragraph "5.5 Installing the OP-TEE" is enough"></securetransclude>{{#set:Has reviews comments=true}}