Configuration

Overview

The Malta platform HAL package is loaded automatically when eCos is configured for a malta 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.

Target Selection

The exact processor type is determined by the target selected during configuration. The following targets are currently supported:

Startup

The Malta platform HAL package supports two startup types:

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 configuration option CYGSEM_HAL_USE_ROM_MONITOR 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.

Flash Driver

The Malta board contains two 16 bit Intel 28F160 flash devices arranged in parallel to form a 32 bit wide interface. The CYGPKG_DEVS_FLASH_INTEL_28FXXX package contains all the code necessary to support these parts and the CYGPKG_DEVS_FLASH_MALTA package contains definitions that customize the driver to the Malta board.

Ethernet Driver

The Malta board contains an AMD Am79C973 PCnet ethernet MAC. The CYGPKG_DEVS_ETH_AMD_PCNET package contains all the code necessary to support this device and the CYGPKG_DEVS_ETH_MIPS_MIPS32_MALTA package contains definitions that customize the driver to the Malta 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.