eduardvercaemer / osakauss

our supper awesome kernel and user space system

osakauss

our super awesome kernel and user space system

memory layout

• The kernel is loaded at 0x00100000.
• kmalloc initially uses 'placement' allocation at the end of the kernel (this allocations are not kfree'ed).
• paging_init creates the kernel directory, identity-mapping everything currently in use (i.e. from 0x00000000 to wherever the placement allocator is currently).
• At this point, kmalloc works as intended, heap allocation, mapped at 0x00800000.

phys. memory bookkeeping

• After initializing paging, the physical memory bookkeper keeps track of the free memory after the 'placement' allocator.

Boot process

• paging init
  • physmem alloc's
    • pre physmem init
    • early allocs
    • non free-able
  • kernel map page
    • more physmem alloc's
  • switch dir
• physmem init
  • reserves more phys memory (identity mapped)
  • sets physmem ready
  • at this point, physmem allocs are free-able
• heap init
  • todo
• syscall init
  • broken