Re: [Prex-devel] Use of phys_to_virt()

[Kohsuke O. <ko...@us...>]

Giovanni Visciano wrote:
> 1) Why does loader_main() [boot/common/main.c] use "phys_to_virt" to get  
> the
>     "kernel_entry" (address of kernel_start()) ?

We have to translate address to the physical address until we enable 
paging. Please check locore.S in i386 kernel.

> 2) Why does elf_load() [boot/common/elf.c] get the initial load address by  
> taking
>     the virtual address from "p_paddr" (Physical address) field of the  
> Elf_Program_Header
>     instead of taking it from "p_vaddr" (Virtual address in memory image) ?

p_paddr of the kernel module is just used to point the kernel load 
address. So, we can put the kernel anywhere regardless of p_vaddr if 
it's needed.

- Kohsuke