// 1) Mark physical page 0 as in use.// This way we preserve the real-mode IDT and BIOS structures// in case we ever need them. (Currently we don't, but...)// 2) The rest of base memory, [PGSIZE, npages_basemem * PGSIZE)// is free.// 3) Then comes the IO hole [IO...
Exercise 2. Look at chapters 5 and 6 of the Intel 80386 Reference Manual, if you haven't done so already. Read the sections about page translation and page-based protection closely (5.2 and 6.4). We recommend that you also skim the sections aboutsegmentation; while JOS uses the paging har...
How to manage memory when programming 80386-based personal computers. Challenges in the multitasking environment; Paging architecture; Microsoft OS/2 virtual memory management. INSET: Enabling and disabling paging on the 80386..MargulisN.DrMargulis, Advanced 80386 Memory Management, Dr. Dobb s Journal...
and cannot be directly used by applications which have not been made aware of its existence. Most likely this memory is mapped into a region using 386 memory management hardware and software or special chipsets
Handle pointers are a Digital Mars C++ extension to the far pointer type that support virtual memory management. You use handle pointers to access expanded memory (EMS or LIMS) in 16-bit programs. Like far pointers, handle pointers are 32 bits long in 16-bit applications. They let a data...
In fact, it is a really great memory management scheme. What is bad is Intel's 1976 implementation of seg- mentation still in use today. You can't blame Intel for this – they fixed the problem in the 80's with the release of the 80386. The real culprit is MS-DOS that forces ...
Incomputing,virtual memory, orvirtual storage[b]is amemory managementtechnique that provides an "idealized abstraction of the storage resources that are actually available on a given machine"[3]which "creates the illusion to users of a very large (main) memory".[4] ...
Protected-Mode Memory Managementby Yariv KaplanWhen the processor is running in protected-mode, two mechanisms are involvedin the memory translation process:SegmentationandPaging. Althoughworking in tandem, these two mechanisms are completely independent of eachother. In fact, the paging unit can be di...
Software emulation of bank-switched memory using a virtual DOS monitor and paged memory management A virtual DOS monitor uses the paging hardware of a processor such as the Intel 80386 microprocessor in conjunction with its Virtual- 8086 mode of operation to emulate expanded memory using extended ...
When the CPU is in Protected Mode,System Management Mode(SMM) is still invisibly active, and cannot be shut off. SMM also seems to use the EBDA. So the EBDA memory area shouldneverbe overwritten. Note: the EBDA is a variable-sized memory area (on different BIOSes). If it exists, ...