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Memory management functions. Currently, only only MAP_ANONYMOUS is supported. It is possible to request memory from a specific pool by supplying a file descriptor to the appropriate /kfs/mem/bank*/ file.

mmap

Map a section of memory into the current process address space.

Syntax

#include <sys/mman.h>

void *mmap (void *addr, size_t length, int prot, int flags, int fd, off_t offset);

Parameters

• addr

  The offset of where to place the mapping. A value of zero means that the kernel is free to select the offset. Only a value of zero is currently allowed.

• length

  The length (size) of memory to allocate.

• prot

  Memory protection to apply. Must be a combination of PROT_READ and PROT_WRITE. PROT_EXEC is not supported.

• flags

  Flags describing the memory allocation. Must be (MAP_PRIVATE | MAP_ANONYMOUS), since only "regular" memory allocation is supported.

• fd

  File descriptor to map in. Currently only available for specifying the memory bank to allocate from, by giving a file descriptor for a file in /kfs/mem/bank*.

  A value of zero means that the kernel is free to choose what memory pool to allocate from.

• offset

  Offset whithin the file. Must be zero.

Return Value

The return value is a pointer to the mapped memory if successful. Otherwise, the return value is null and errno is set:

• EINVAL

  Operation not supported. May be returned if there was an internal system call error or the API is not available because it has been disabled.

  The length is zero.

  Invalid or unknown flags.

  Flags are not (MAP_PRIVATE | MAP_ANONYMOUS) (unsupported).

• ENOTSUP

  Non-null address is not supported.

  Executable memory is not allowed.

• ENOMEM

  Out of memory.

Remarks

None

munmap

Un-map a section of memory.

Syntax

#include <sys/mman.h>

int munmap (void *addr, size_t length);

Parameters

• addr

  The offset/address of the memory to unmap.

• length

  The length (size) of memory to de-allocate.

Return Value

The return value is zero successful. Otherwise, the return value is negative and errno is set:

• EINVAL

  Operation not supported. May be returned if there was an internal system call error or the API is not available because it has been disabled.

  The address is not valid.

Remarks

None