25 lines
889 B
Markdown
25 lines
889 B
Markdown
*Concepts you may want to Google beforehand: malloc*
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**Goal: Implement a memory allocator**
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We will add a kernel memory allocator to `libc/mem.c`. It is
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implemented as a simple pointer to free memory, which keeps
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growing.
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The `kmalloc()` function can be used to request an aligned page,
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and it will also return the real, physical address, for later use.
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We'll change the `kernel.c` leaving all the "shell" code there,
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Let's just try out the new `kmalloc()`, and check out that
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our first page starts at 0x10000 (as hardcoded on `mem.c`) and
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subsequent `kmalloc()`'s produce a new address which is
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aligned 4096 bytes or 0x1000 from the previous one.
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Note that we added a new `strings.c:hex_to_ascii()` for
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nicer printing of hex numbers.
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Another cosmetic modification is to rename `types.c` to
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`type.c` for language consistency.
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The rest of the files are unchanged from last lesson.
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