more work on linker , closer to load to memory

This commit is contained in:
georgemoralis 2023-05-23 19:39:24 +03:00
parent b27942c46b
commit 5d0a5af495
4 changed files with 48 additions and 28 deletions

View File

@ -4,30 +4,6 @@
namespace Memory
{
static u64 get_aligned_size(const elf_program_header* phdr)
{
return (phdr->p_align != 0 ? (phdr->p_memsz + (phdr->p_align - 1)) & ~(phdr->p_align - 1) : phdr->p_memsz);
}
static u64 calculate_base_size(const elf_header* ehdr, const elf_program_header* phdr)
{
u64 base_size = 0;
for (u16 i = 0; i < ehdr->e_phnum; i++)
{
if (phdr[i].p_memsz != 0 && (phdr[i].p_type == PT_LOAD || phdr[i].p_type == PT_SCE_RELRO))
{
auto phdrh = phdr + i;
u64 last_addr = phdr[i].p_vaddr + get_aligned_size(phdrh);
if (last_addr > base_size)
{
base_size = last_addr;
}
}
}
return base_size;
}
namespace VirtualMemory {
u64 memory_alloc(u64 address, u64 size)

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@ -2,9 +2,6 @@
namespace Memory
{
static u64 get_aligned_size(const elf_program_header* phdr);
static u64 calculate_base_size(const elf_header* ehdr, const elf_program_header* phdr);
namespace VirtualMemory {
u64 memory_alloc(u64 address, u64 size);
}

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@ -1,4 +1,5 @@
#include "Linker.h"
#include "../Memory.h"
Linker::Linker()
{
@ -8,12 +9,43 @@ Linker::~Linker()
{
}
static u64 get_aligned_size(const elf_program_header* phdr)
{
return (phdr->p_align != 0 ? (phdr->p_memsz + (phdr->p_align - 1)) & ~(phdr->p_align - 1) : phdr->p_memsz);
}
static u64 calculate_base_size(const elf_header* ehdr, const elf_program_header* phdr)
{
u64 base_size = 0;
for (u16 i = 0; i < ehdr->e_phnum; i++)
{
if (phdr[i].p_memsz != 0 && (phdr[i].p_type == PT_LOAD || phdr[i].p_type == PT_SCE_RELRO))
{
auto phdrh = phdr + i;
u64 last_addr = phdr[i].p_vaddr + get_aligned_size(phdrh);
if (last_addr > base_size)
{
base_size = last_addr;
}
}
}
return base_size;
}
Module* Linker::LoadModule(const std::string& elf_name)
{
auto* m = new Module;
m->elf = new Elf;
m->elf->Open(elf_name);//load elf
if (m->elf->isElfFile())
{
LoadModuleToMemory(m);
}
else
{
return nullptr;//it is not a valid elf file //TODO check it why!
}
m_modules.push_back(m);//added it to load modules
return m;
@ -29,4 +61,16 @@ Module* Linker::FindModule(/*u32 id*/)
return m;
}
return nullptr;
}
void Linker::LoadModuleToMemory(Module* m)
{
//get elf header, program header
auto* elf_header = m->elf->GetElfHeader();
auto* elf_pheader = m->elf->GetProgramHeader();
u64 base_size = calculate_base_size(elf_header,elf_pheader);
m->aligned_base_size = (base_size & ~(static_cast<u64>(0x1000) - 1)) + 0x1000;//align base size to 0x1000 block size (TODO is that the default block size or it can be changed?
}

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@ -6,6 +6,8 @@
struct Module
{
Elf* elf = nullptr;
u64 aligned_base_size = 0;
u64 base_virtual_addr = 0; //base virtual address
};
class Linker
@ -16,6 +18,7 @@ public:
Module* LoadModule(const std::string& elf_name);
Module* FindModule(/*u32 id*/);
void LoadModuleToMemory(Module* m);
private:
std::vector<Module*> m_modules;