How will first megabyte memory layout be changed in Protected Mode?
As far as I understand when we are in x86 Real Mode the first megabyte memory layot looks like that:
Will memory layot be changed once we jump to Protected Mode? I know that we can access video memory by the same address like we did it the Real Mode but what about other regions? Can we overwrite them? I suppose we don't need the IVT and the boot sector anymore. But I'm not sure about others.
Short answer: No.
Long answer: The layout of memory does not change depending on what mode you are in. However, when not in real mode, most of the memory in that region is irrelevant to you, and can be used. However, you must know that a LOT of memory in that region may be IO-mapped, and thus, it is a good idea to load your kernel >1M (2M is the optimal place) and to ignore the first 1M of memory.
Once you implement paging and page allocation, you will want to reserve the first megabyte of memory, thus not allowing it to be allocated.
- Why the memory content is not read? - verilog digital system design
- I see undefined output sequences reading a memory in simulation
- Custom vector class with CUDA backend
- Can madvise(addr, size, MADV_DONTNEED) cause segfaults?
- SpringBoot application memory consistently exceeds JVM configured heap size
- Variable address does not fall within the stack range in /proc/self/maps
- Stack and heap misunderstanding in Swift
- C++ deleting array on the heap
- How much of ‘What Every Programmer Should Know About Memory’ is still valid?
- How to assign more memory to Netbeans?
- Using "%d" to print double variable outputs differently in IA32 and IA32-64
- Using the layout of a different struct pointer
- serial memory pages (virtual memory) and TLB hit
- Memory Alignment in C/C++
- What role does min value and max value play in reducing memory usage?
- Why Linux has 4 layers of "page tables" and how it works exactly
- Alternative reasons for "out of memory" error than lack of free global memory?
- When deleting my circular linked list class, the L variable turns into random addresses
- asizeof appears to be inaccurate
- Arranging global/static objects sequentially in memory
- C++11 lambda implementation and memory model
- Do all programs need to have a stack and a heap?
- Is there a way to code data directly to the hard drive (similar to how one can do with RAM)?
- Where static objects are stored in Java?
- Visual studio 2022 highly used memory
- There is insufficient system memory in resource pool 'default' to run this query
- Python in-memory zip library
- Memory hacking / memory allocation : why does this work and how?
- Circular References Cause Memory Leak?
- memory sharing in .o file