Freescale Semiconductor i.MX 6DualLite, Справочное руководство

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3.3.3 Timer Source Code Structure
The timer module is implemented in the arch/arm/plat-mxc/time.c file.
3.3.4 Timer Programming Interface
The timer module utilizes four hardware timers, to implement clock source and clock
event objects.
This is done with the clocksource_mxc structure of struct clocksource type and
clockevent_mxc structure of struct clockevent_device type. Both structures provide
routines required for reading current timer values and scheduling the next timer event.
The module implements a timer interrupt routine that services the Linux OS with timer
events for the purposes mentioned in the beginning of this chapter.
3.4 Memory Map
A predefined virtual-to-physical memory map table is required for the device drivers to
access to the device registers since the Linux kernel is running under the virtual address
space with the Memory Management Unit (MMU) enabled.
3.4.1 Memory Map Hardware Operation
The MMU, as a part of the ARM core, provides the virtual-to-physical address mapping
defined by the page table. For more information, see the ARM Technical Reference
Manual
(TRM) from ARM Limited.
3.4.2 Memory Map Software Operation
A table mapping the virtual memory to physical memory is implemented for i.MX
platforms as defined in the file in <ltib_dir>/rpm/BUILD/linux/arch/arm/mach-mx6/
mm.c .
Chapter 3 Machine Specific Layer (MSL)
i.MX 6Solo/6DualLite Linux Reference Manual, Rev. L3.0.35_4.1.0, 09/2013
Freescale Semiconductor, Inc. 37