Configuration — Platform-specific Configuration Options
The ADS512101 platform HAL package is loaded automatically when
eCos is configured for an
ads512101 target. It
should never be necessary to load this package
explicitly. Unloading the package should only happen as a side
effect of switching target hardware.
The ADS512101 platform HAL package supports four separate startup types:
- This is the startup type which is normally used during application development. The board has ROMRAM RedBoot running from 0x00000000 and applications will be loaded from 0x00100000. powerpc-eabi-gdb is then used to load a RAM startup application into memory and debug it. It is assumed that the hardware has already been initialized by RedBoot. By default the application will use the eCos virtual vectors mechanism to obtain certain services from RedBoot, including diagnostic output.
- This startup type can be used for finished applications which will be programmed into flash at location 0xFFF00000. The application will be self-contained with no dependencies on services provided by other software. eCos startup code will perform all necessary hardware initialization.
- This startup type can be used for finished applications which will be programmed into flash at location 0xFFF00000. The first thing the application does is to relocate itself to RAM at location 0x00000000. The application will be self-contained with no dependencies on services provided by other software. eCos startup code will perform all necessary hardware initialization.
- This startup type can be used for finished applications which will be loaded into external RAM via a JTAG debugger. The application will be self-contained with no dependencies on services provided by other software. The JTAG debugger should initialize the hardware enough to load the code into RAM, eCos startup code will perform any further hardware initialization.
RedBoot and Virtual Vectors
If the application is intended to act as a ROM monitor, providing
services for other applications, then the configuration option
CYGSEM_HAL_ROM_MONITOR should be set. Typically
this option is set only when building RedBoot.
If the application is supposed to make use of services provided by
a ROM monitor, via the eCos virtual vector mechanism, then the
should be set. By default this option is enabled when building for
a RAM startup, disabled otherwise. It can be manually disabled for
a RAM startup, making the application self-contained, as a testing
step before switching to ROM startup.
If the application does not rely on a ROM monitor for diagnostic services then the serial port will be claimed for HAL diagnostics.
The ADS512101 board contains 64MiB of flash memory. The
contains all the code necessary to support access to the
flash. The ADS512101 platform HAL package contains definitions
that customize the driver to the ADS512101 board.
By default, the system clock interrupts once every 10ms,
corresponding to a 100Hz clock. This can be changed by the
which corresponds to the clock frequency. Other clock-related
settings are recalculated automatically if the denominator is
The ADS512101 board uses the MPC5121e's internal FEC ethernet
device attached to an external PHY. The
CYGPKG_DEVS_ETH_POWERPC_FEC package contains
all the code necessary to support this device. The
contains definitions that customize the driver to the ADS512101
board. This driver is not active until the generic Ethernet
included in the configuration.
The ADS512101 board uses an ST M41T662 I²C Real Time Clock. The
contains all the code necessary to support this device. This
device also needs the
CYGPKG_IO_I2C package to
be loaded. This driver is not active until the generic wallclock
device support package,
included in the configuration.
The ADS512101 board uses the MPC5121e's internal watchdog
package contains all the code necessary to support this
device. Within that package the
configuration option controls the watchdog timeout, and by default
will force a reset of the board upon timeout. This driver is not
active until the generic watchdog device support package,
CYGPKG_IO_WATCHDOG, is included in the
UART Serial Driver
The ADS512101 board uses the MPC5121e's Programmable Serial Controllers (PSC's) configured for UART mode. Two serial UART adaptors are available on the board. However, only PSC3 is attached to a ( pin D-Sub connector. PSC4 is connected to header P8.
The MPC512X HAL contains a driver for the I²C busses on the board. There are several devices attached to the busses, of which, only the RTC on Bus0 is actually used bt eCos.
The MPC512X contains four Freescale MSCAN devices, although only
one of these is brought out to an external connector. The package
CYGPKG_DEVS_CAN_MSCAN is a general driver for
the MSCAN, and the package
CYGPKG_DEVS_CAN_ADS512101 configures this for the
The platform HAL defines the default compiler and linker flags for all packages, although it is possible to override these on a per-package basis. Most of the flags used are the same as for other architectures supported by eCos. There is one flag specific to this port:
The powerpc-eabi-gcc compiler supports many
variants of the PowerPC architecture.
-moption should be used to select the specific variant in use. The MPC5121e is a e300c4 processor, and the current tools do not have an option to select this processor directly so instead we select a processor that is identical as far as the compiler is concerned, the e300c3.
|2018-06-19||eCosPro Non-Commercial Public License|