Chapter 3
Machine Specific Layer (MSL)
3.1 Introduction
The Machine Specific Layer (MSL) provides the Linux kernel with the following
machine-dependent components:
• Interrupts including GPIO and EDIO (only on certain platforms)
• Timer
• Memory map
• General Purpose Input/Output (GPIO) including IOMUX on certain platforms
• Shared Peripheral Bus Arbiter (SPBA)
• Smart Direct Memory Access (SDMA)
These modules are normally available in the following directory:
<ltib_dir>/rpm/BUILD/linux/arch/arm/mach-mx6 for i.MX 6 platform
The header files are implemented under the following directory:
<ltib_dir>/rpm/BUILD/linux/arch/arm/plat-mxc/include/mach
The MSL layer contains not only the modules common to all the boards using the same
processor, such as the interrupts and timer, but it also contains modules specific to each
board, such as the memory map. The following sections describe the basic hardware and
software operations and the software interfaces for MSL modules. First, the common
modules, such as Interrupts and Timer are discussed. Next, the board-specific modules,
such as Memory Map and General Purpose Input/Output (GPIO) (including IOMUX on
some platforms) are detailed. Because of the complexity of the SDMA module, its design
is explained in SDMA relevant chapter.
Each of the following sections contains an overview of the hardware operation. For more
information, see the corresponding device documentation.
i.MX 6Solo/6DualLite Linux Reference Manual, Rev. L3.0.35_4.1.0, 09/2013
Freescale Semiconductor, Inc.
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