mirror of
https://github.com/justinian/jsix.git
synced 2025-12-10 00:14:32 -08:00
4f4a35a7be
Set up initial page tables for both the offset-mapped area and the loaded kernel code and data. * Got rid of the `loaded_elf` struct - the loader now runs after the initial PML4 is created and maps the ELF sections itself. * Copied in the `page_table` and `page_table_indices` from the kernel, still need to clean this up and extract it into shared code. * Added `page_table_cache` to the kernel args to pass along free pages that can be used for initial page tables. Tags: paging
84 lines
2.2 KiB
C++
84 lines
2.2 KiB
C++
#include <uefi/boot_services.h>
|
|
#include <uefi/types.h>
|
|
|
|
#include "loader.h"
|
|
#include "console.h"
|
|
#include "elf.h"
|
|
#include "error.h"
|
|
#include "memory.h"
|
|
#include "paging.h"
|
|
|
|
namespace boot {
|
|
namespace loader {
|
|
|
|
static bool
|
|
is_elfheader_valid(const elf::header *header)
|
|
{
|
|
return
|
|
header->magic[0] == 0x7f &&
|
|
header->magic[1] == 'E' &&
|
|
header->magic[2] == 'L' &&
|
|
header->magic[3] == 'F' &&
|
|
header->word_size == elf::word_size &&
|
|
header->endianness == elf::endianness &&
|
|
header->os_abi == elf::os_abi &&
|
|
header->machine == elf::machine &&
|
|
header->header_version == elf::version;
|
|
}
|
|
|
|
static void
|
|
map_pages(
|
|
paging::page_table *pml4,
|
|
kernel::args::header *args,
|
|
uintptr_t phys, uintptr_t virt,
|
|
size_t bytes)
|
|
{
|
|
}
|
|
|
|
kernel::entrypoint
|
|
load(
|
|
const void *data, size_t size,
|
|
kernel::args::header *args,
|
|
uefi::boot_services *bs)
|
|
{
|
|
status_line status(L"Loading kernel ELF binary");
|
|
const elf::header *header = reinterpret_cast<const elf::header*>(data);
|
|
|
|
if (size < sizeof(elf::header) || !is_elfheader_valid(header))
|
|
error::raise(uefi::status::load_error, L"Kernel ELF not valid");
|
|
|
|
paging::page_table *pml4 = reinterpret_cast<paging::page_table*>(args->pml4);
|
|
|
|
for (int i = 0; i < header->ph_num; ++i) {
|
|
ptrdiff_t offset = header->ph_offset + i * header->ph_entsize;
|
|
const elf::program_header *pheader =
|
|
offset_ptr<elf::program_header>(data, offset);
|
|
|
|
if (pheader->type != elf::PT_LOAD)
|
|
continue;
|
|
|
|
size_t num_pages = memory::bytes_to_pages(pheader->mem_size);
|
|
void *pages = nullptr;
|
|
|
|
try_or_raise(
|
|
bs->allocate_pages(uefi::allocate_type::any_pages,
|
|
memory::kernel_type, num_pages, &pages),
|
|
L"Failed allocating space for kernel code");
|
|
|
|
void *data_start = offset_ptr<void>(data, pheader->offset);
|
|
bs->copy_mem(pages, data_start, pheader->mem_size);
|
|
|
|
console::print(L" Kernel section %d physical addr: 0x%lx\r\n", i, pages);
|
|
console::print(L" Kernel section %d virtual addr: 0x%lx\r\n", i, pheader->vaddr);
|
|
|
|
// TODO: map these pages into kernel args' page tables
|
|
// remember to set appropriate RWX permissions
|
|
map_pages(pml4, args, reinterpret_cast<uintptr_t>(pages), pheader->vaddr, pheader->mem_size);
|
|
}
|
|
|
|
return reinterpret_cast<kernel::entrypoint>(header->entrypoint);
|
|
}
|
|
|
|
} // namespace loader
|
|
} // namespace boot
|