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Kernel/x86: Bake the Prekernel and the Kernel into one image

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The new baked image is a Prekernel and a Kernel baked together now, so
essentially we no longer need to pass the Prekernel as -kernel and the
actual  kernel image as -initrd to QEMU, leaving the option to pass an
actual initrd or initramfs module later on with multiboot.
This commit is contained in:
Liav A 2023-03-24 20:31:53 +03:00 • committed by Jelle Raaijmakers
parent 2a1e58f8cc
commit 897c4e5145
10 changed files with 81 additions and 50 deletions
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27
Kernel/Prekernel/init.cpp
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@ -27,6 +27,9 @@ extern "C" [[noreturn]] void __stack_chk_fail();
extern "C" u8 start_of_prekernel_image[];
extern "C" u8 end_of_prekernel_image[];
extern "C" u8 _binary_Kernel_standalone_start[];
extern "C" u8 end_of_prekernel_image_after_kernel_image[];
extern "C" u8 gdt64ptr[];
extern "C" u16 code64_sel;
extern "C" u64 boot_pml4t[512];
@ -76,12 +79,7 @@ u64 generate_secure_seed();
extern "C" [[noreturn]] void init()
{
if (multiboot_info_ptr->mods_count < 1)
halt();
multiboot_module_entry_t* kernel_module = (multiboot_module_entry_t*)(FlatPtr)multiboot_info_ptr->mods_addr;
u8* kernel_image = (u8*)(FlatPtr)kernel_module->start;
u8* kernel_image = _binary_Kernel_standalone_start;
// copy the ELF header and program headers because we might end up overwriting them
ElfW(Ehdr) kernel_elf_header = *(ElfW(Ehdr)*)kernel_image;
ElfW(Phdr) kernel_program_headers[16];
@ -89,8 +87,8 @@ extern "C" [[noreturn]] void init()
halt();
__builtin_memcpy(kernel_program_headers, kernel_image + kernel_elf_header.e_phoff, sizeof(ElfW(Phdr)) * kernel_elf_header.e_phnum);
FlatPtr kernel_physical_base = 0x200000;
FlatPtr default_kernel_load_base = KERNEL_MAPPING_BASE + 0x200000;
FlatPtr kernel_physical_base = (FlatPtr)kernel_image;
FlatPtr default_kernel_load_base = KERNEL_MAPPING_BASE + kernel_physical_base;
FlatPtr kernel_load_base = default_kernel_load_base;
@ -168,9 +166,6 @@ extern "C" [[noreturn]] void init()
__builtin_memset((u8*)kernel_load_base + kernel_program_header.p_vaddr + kernel_program_header.p_filesz, 0, kernel_program_header.p_memsz - kernel_program_header.p_filesz);
}
multiboot_info_ptr->mods_count--;
multiboot_info_ptr->mods_addr += sizeof(multiboot_module_entry_t);
auto adjust_by_mapping_base = [kernel_mapping_base](auto ptr) {
return (decltype(ptr))((FlatPtr)ptr + kernel_mapping_base);
};
@ -194,8 +189,16 @@ extern "C" [[noreturn]] void init()
info.multiboot_flags = multiboot_info_ptr->flags;
info.multiboot_memory_map = adjust_by_mapping_base((FlatPtr)multiboot_info_ptr->mmap_addr);
info.multiboot_memory_map_count = multiboot_info_ptr->mmap_length / sizeof(multiboot_memory_map_t);
info.multiboot_modules = adjust_by_mapping_base((FlatPtr)multiboot_info_ptr->mods_addr);
info.multiboot_modules_physical_ptr = (FlatPtr)multiboot_info_ptr->mods_addr;
info.multiboot_modules_count = multiboot_info_ptr->mods_count;
if (info.multiboot_modules_count > 0) {
auto* entry = reinterpret_cast<multiboot_module_entry*>(multiboot_info_ptr->mods_addr);
info.multiboot_module_ramdisk_physical_start = entry->start;
info.multiboot_module_ramdisk_physical_end = entry->end;
info.multiboot_module_ramdisk_physical_string_addr = entry->string_addr;
}
if ((multiboot_info_ptr->flags & MULTIBOOT_INFO_FRAMEBUFFER_INFO) != 0) {
info.multiboot_framebuffer_addr = multiboot_info_ptr->framebuffer_addr;
info.multiboot_framebuffer_pitch = multiboot_info_ptr->framebuffer_pitch;