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US 2003/0126398 A1Published application
Memory protection control device and method
AssigneeSony Corporation
InventorIkuo Shinozaki
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AssigneeSony Corporation
InventorIkuo Shinozaki
Estimating the term…
The present invention provides a memory protective administrative apparatus for a computer for protecting memory access between programs. A virtual address administrative apparatus constituting the first mentioned apparatus receives size of a memory region prepared, and assigns a virtual address region larger than the size. At this time, a top address of a region smaller than size S1 covered by 1-entry of the minimum segment table performs virtual address assigning so as to be aligned to the size S1. In a region of size larger than the S1, hierarchies in which the size can be covered by 1-entry are searched from bottom, and likewise, a virtual address aligned is assigned. A page table is variable in length and has a page entry for a size part. The page table is linked to entry corresponding to the top virtual address of a segment table of a hierarchy used for alignment.
A memory protective administrative apparatus for a computer for using a page table and a segment table of a multi-hierarchy or a single hierarchy to protect and administer memory regions, wherein when a protected memory region is produced in response to a memory assigning request, a virtual address is assigned to said protected memory region so as to have a multiple of size of an address covered by 1-entry of a segment table of a predetermined hierarchy out of segment tables of said multi-hierarchy, and size closest to said memory region, or a multiple of size covered by 1-entry of said segment table of a single hierarchy, a page table for administering the correspondence between the virtual address assigned to said memory region and a physical page is produced, and the page table is linked to an entry of said segment table of a predetermined hierarchy or an entry of said segment table of a single hierarchy by the assigned virtual address.
A memory protective administrative method for a computer for using a page table and a segment table of a multi-hierarchy or a single hierarchy to protective administer memory regions, comprising the steps of:
Dependencies are inferred from the claim text.