HAL Port — Implementation Details
This documentation explains how the eCos HAL specification has been mapped onto the M5282EVB hardware, and should be read in conjunction with that specification. The M5282EVB platform HAL package complements the M68K architectural HAL, the MCFxxxx variant HAL, and the MCF5282 processor HAL. It provides functionality which is specific to the target board.
Following a hard or soft reset the HAL will initialize or
reinitialize most of the on-chip peripherals. There is an exception
for RAM startup applications which depend on a ROM monitor for certain
services: the UARTs and the ethernet device will not be reinitialized
because they may be in use by RedBoot for communication with the host.
Full details of this initialization can be found in the function
For a ROM or ROMFFE startup the HAL will perform additional
initialization, setting up the external DRAM and programming the
various internal registers. The values used for some of these
registers are configurable. Full
details can be found in the exported header
The platform HAL provides configuration options for the eCos system clock. This always uses the hardware timer PIT3, which should not be used directly by application code. The actual HAL macros for managing the clock are provided by the MCF5282 processor HAL. The specific numbers used are a characteristic of the platform because they depend on the processor speed. The gprof-based profiling code uses PIT2. Timers PIT0 and PIT1 are not used by eCos so application code is free to manipulate these as required.
The M5282EVB platform HAL does not affect the implementation of other parts of the eCos HAL specification. The MCF5282 processor HAL, the MCFxxxx variant HAL, and the M68K architectural HAL documentation should be consulted for further details.
The platform HAL package also provides a flash driver for the off-chip
AMD AM29LV160 flash chip. This driver is inactive by default, and
only becomes active if the configuration includes the generic flash
The platform HAL provides one additional function to manipulate the
which argument specifies the
LED and should be either 0 or 1. The
should be non-zero to switch the LED on, zero to switch it off. Note
that only two of the four user LEDs can be manipulated in this way:
the other two are normally connected to signals needed by one of the
|2022-03-29||eCosPro Non-Commercial Public License|