Configuration

Name

Configuration -- Platform-specific Configuration Options

Overview

The IQ80321 platform HAL package is loaded automatically when eCos is configured for a iq80321 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.

Startup

The IQ80321 platform HAL package supports two separate startup types:

RAM

This is the startup type which is normally used during application development. The board has RedBoot programmed into flash and boots into that initially. arm-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.

ROM

This startup type can be used for finished applications which will be programmed into flash at physical address 0xF0000000. The application will be self-contained with no dependencies on services provided by other software. eCos startup code will perform all necessary 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 required to make use of services provided by a ROM monitor, via the eCos virtual vector mechanism, then the configuration option CYGSEM_HAL_USE_ROM_MONITOR should be set. By default this option is enabled when building for RAM startup, disabled otherwise. It can be manually disabled for 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.

Flash Driver

The IQ80321 board contains an 8MB Intel StrataFlash flash device. The CYGPKG_DEVS_FLASH_STRATA package contains all the code necessary to support these parts and the CYGPKG_DEVS_FLASH_IQ80321 package contains definitions that customize the driver to the IQ80321 board.

Ethernet Driver

The IQ80321 board contains an Intel i82544 ethernet controller. The CYGPKG_DEVS_ETH_INTEL_I82544 package contains all the code necessary to support this device and the CYGPKG_DEVS_ETH_ARM_IQ80321 package contains definitions that customize the driver to the IQ80321 board.

System Clock

By default, the system clock interrupts once every 10ms, corresponding to a 100Hz clock. This can be changed by the configuration option CYGNUM_HAL_RTC_DENOMINATOR which corresponds to the clock frequency. Other clock-related settings are recalculated automatically if the denominator is changed.

Compiler Flags

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 just one flag specific to this port:

-mcpu=xscale

The arm-eabi-gcc compiler supports many variants of the ARM architecture. A -m option should be used to select the specific variant in use, and with current tools -mcpu=xscale is the correct option for the XScale CPU on the IOP321.

2017-02-09
Documentation license for this page: eCosPro License