PSDHLP_VMALLOC

PSDHLP_VMALLOC keywords

May Block

Description
Allocate memory.

This function is used to allocate virtual memory, or map virtual memory to physical memory, depending on the value of the flags. All virtual addresses are allocated from the system arena (i.e. global address space).

Mode
Callable in Init and Kernel mode.

Parameters
Pointer to a VMALLOC structure.

Exit
Return code.

Structures

typedef struct vmalloc_s
{
   ulong_t addr;    (Input/Output)
   ulong_t cbsize;  (Input)
   ulong_t flags;   (Input)
} VMALLOC;

addr

is filled with the linear address of the allocated or mapped memory on return from the help.

If VMALLOC_LOCSPECIFIC is specified, this field must contain the virtual address to map before calling the help.

If VMALLOC_PHYS is specified, this field must contain the physical address to map before calling the help.

cbsize
is the size of the allocation, or mapping in bytes.
flags
indicate which type of operation is to be performed.

VMALLOC_FIXED

indicates that the allocated memory is to be fixed in memory (not-swappable or movable). If this flag is omitted, the allocated memory will be swappable by default.
VMALLOC_CONTIG
indicates that the allocation must use contigous physical memory. If this flag is specified VMALLOC_FIXED must also be used.
VMALLOC_LOCSPECIFIC
indicates a request for a memory allocation at a specific virtual address. If this flag is specified, the addr field must contain the virtual address to map.

Note: This flag can be used with the VMALLOC_PHYS flag to allocate memory where linear = physical.

VMALLOC_PHYS
indicates a request for a virtual mapping of physical memory. If this flag is specified, the addr field must contain the physical address to map.

Note: This flag can be used with the VMALLOC_LOCSPECIFIC flag to allocate memory where linear = physical.

VMALLOC_1M
indicates a request for a memory allocation below the 1MB boundary.
Notes
None.

---

[Back: PSD Helps]
[Next: PSDHLP_VMFREE]