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Diffstat (limited to 'doc/mach.texi')
| -rw-r--r-- | doc/mach.texi | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/doc/mach.texi b/doc/mach.texi index dcf0f93c..91ec96ee 100644 --- a/doc/mach.texi +++ b/doc/mach.texi @@ -3056,6 +3056,30 @@ specified and @code{KERN_NO_SPACE} if there was not enough space left to satisfy the request. @end deftypefun +@deftypefun kern_return_t vm_allocate_contiguous (@w{host_priv_t @var{host_priv}}, @w{vm_task_t @var{target_task}}, @w{vm_address_t *@var{vaddr}}, @w{phys_addr_t *@var{paddr}}, @w{vm_size_t @var{size}}, @w{phys_addr_t @var{pmin}}, @w{phys_addr_t @var{pmax}}, @w{phys_addr_t @var{palign}}) +The function @code{vm_allocate} allocates a region of physical memory, +placing virtual mapping of the physical pages in the specified @var{task}'s +address space. + +The virtual space will be allocated wherever it is available. The virtual +address at which the physical memory was mapped will be returned in +@var{vaddr}. The physical address of the start of the allocated physical +memory will be returned in @var{paddr}. + +@var{size} is the number of bytes to allocate (rounded by the system in +a machine dependent way to an integral number of virtual pages). + +Constraints can be set on the physical address, to cope with hardware physical +memory access constraints, e.g. DMAs. @var{pmin} is the minimum physical address +at which the allocated memory should start. @var{pmax} is the maximum physical +address at which the allocated memory should end. @var{palign} is the alignment +restriction, which has to be a power of two. + +The function returns @code{KERN_SUCCESS} if the memory was successfully +allocated, @code{KERN_RESOURCE_SHORTAGE} if there was not enough physical memory +left to satisfy the request, and @code{KERN_NO_SPACE} if there was not enough +virtual space left to satisfy the request. +@end deftypefun @node Memory Deallocation @section Memory Deallocation |