RAM 6.0 BUX II Series Guia do Utilizador descarregar pdf (Página 38)

VxWorks

BSP Developer’s Guide, 6.0

initialized statically during compile time, but it may also be initialized

dynamically early in the boot process.

Values for statically defined sysPhysMemDesc[ ] entries are assigned using

descriptive macro names.

The kinds of memory described by sysPhysMemDesc[ ] entries include system

RAM, flash or ROM, memory mapped processor registers, board registers,

memory mapped device registers including PCI memory space, vector table, static

RAM, or anything else that uses a memory mapped address range.

The fields included in the

PHYS_MEM_DESC structure are, in order:

virtualAddr

The virtual address of the beginning of the memory region.

physicalAddr

The physical address of the beginning of the memory region.

len

The length, in bytes, of the memory region.

initialStateMask

A mask for the initial VM state.

initialState

The initial state that the memory management library should set the memory

to.

The masks used in initalStateMask are defined in vmLib.h:

VM_STATE_MASK_VALID

VM_STATE_MASK_WRITABLE

VM_STATE_MASK_CACHEABLE

VM_STATE_MASK_MEM_COHERENCY

VM_STATE_MASK_GUARDED

Additional mask values may be available on some architectures. Check

vmLib.h and the appropriate architecture supplement for more information.

NOTE: VxWorks is a 32-bit OS, so it supports 32-bit virtual addressing.

However, on hardware that provides address space larger than 32 bits,

VxWorks does support a physical addressing space of up to 64 bits.

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