How can I page align all sections in PT_LOAD program header?

Question

I am trying to implement custom loader with linker script and elf file.

I can successfully load PT_LOAD type program header which can contain .text, .data section in it.

But what I really want is loading each data and text "section" separately and page-aligned.

I could successfully locate each section included in the PT_LOAD program header so far.

However, I need this section be page-aligned(0x1000) to load it separated page.

How can I locate all section in the specific program header be page-aligned ?

Answer 1

make each section page aligned.

e.g. get each section check if it is equal to page size (e.g 0x1000) if its more than that of your page round it to page size. Have some routine similar to listed below.

#define ROUND_TO_PAGE(x,y) (((x) + (y)) & (~(y)))
x = your section
y = page_size - 1 & page_size = 4096 (i.e.yours - 0x1000)