modularkernel-developer

[Modularkernel-developer] linkerscript.ld

[Tomas K. <tom...@gm...>]

Hi,

I am trying to understand the following part of the linker script:

        __RealStartOfLinkedMemory = ALIGN(4096);
        . = 0xFFC00000;
        __StartOfLinkedMemory = .;
        .linked : AT (__RealStartOfLinkedMemory)
        {
                *(.linked)
                *(.linked_data)
        }
        __EndOfLinkedMemory = .;
        ____KERNELEND = (__EndOfLinkedMemory -
__StartOfLinkedMemory)+(__RealStartOfLinkedMemory);

This is what I think it does:
- the .linked section is copied to frames immediatelly following the
.bss section.
- the .linked section is available starting at virtual address 0xFFC00000

Why is it done this way?
Is the .linked section going to contain kernel data to be shared by
every user-space process?

Tomas

[Modularkernel-developer] linkerscript.ld

[Daniel O. <mus...@go...>]

Hi, yes, that's exactly whats done there.
The linked section is the section which contains code (and data in the 
*_data section) that must be available to every task in the later 
operating system. So i will link that section into every virtual address 
space.
Perhaps it is important to add that this "linked section" is somehow 
different from other operating systems such as linux (or windows), 
because only a very small part of the kernel code is linked and not 
(nearly?) all of it.