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homepage/content/projects/noxos/docs/codebase/mm/page_frame.h.md

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page_frame.h physical memory management

PFRAME_SIZE - macro

The size of one page (4KB).

page_frame_manager_T - struct

Name Type Description
free_memory uint64_t The amount of free/usable memory in bytes
reserved_memory uint64_t The amount of reserved memory in bytes
used_memory uint64_t The amount of memory used by noxos in bytes
page_bitmap_index uint64_t The index to the first free page
page_bitmap bitmap_T A huge bitmap, that stores, which pages are claimable and which are already in use
blocked bool Thread safety guard

pframe_manager_init() - function (void)

Initializes the page frame manager, needs to be called once at kernel init.

pframe_reserve(address) - function (void) [Thread Safe]

Blocks a page, so it can't be requested or anything else. If the page is already blocked by anything else, e.g. by a request, it won't be reserved.

pframe_reserve_multi(address, n) - function (void) [Thread Safe]

Reserves the page at the given address, plus n pages after that page.

pframe_unreserve(address) - function (void) [Thread Safe]

Unreserves a reserved page and makes it accessible again.

pframe_unreserve_multi(address, n) - function (void) [Thread Safe]

Unreserves the page at the given address, plus n pages after that page.

pframe_request() - function (void*) [Thread Safe]

Returns the physical address of a page. This is kind of the low level version of memory_allocate.

pframe_free(address) - function (void) [Thread Safe]

Needs a valid page address produced by pframe_request as argument. Invalidates the address and frees it, so it can be requested again. This is kind of the low level version of memory_free.

pframe_free_multi(address, n) - function (void) [Thread Safe]

Frees the page at the given address, plus n pages after that page.