ZealOS/zealbooter/zealbooter.c
2022-09-11 07:12:31 +02:00

338 lines
9.9 KiB
C

#include <stdint.h>
#include <stddef.h>
#include <limine.h>
#include <lib.h>
#include <idt.h>
static volatile struct limine_module_request module_request = {
.id = LIMINE_MODULE_REQUEST,
.revision = 0
};
static volatile struct limine_hhdm_request hhdm_request = {
.id = LIMINE_HHDM_REQUEST,
.revision = 0
};
static volatile struct limine_memmap_request memmap_request = {
.id = LIMINE_MEMMAP_REQUEST,
.revision = 0
};
static volatile struct limine_framebuffer_request framebuffer_request = {
.id = LIMINE_FRAMEBUFFER_REQUEST,
.revision = 0
};
static volatile struct limine_smbios_request smbios_request = {
.id = LIMINE_SMBIOS_REQUEST,
.revision = 0
};
struct CZXE {
uint16_t jmp;
uint8_t module_align_bits;
uint8_t reserved;
uint32_t signature;
int64_t org;
int64_t patch_table_offset;
int64_t file_size;
} __attribute__((packed));
struct CDate {
uint32_t time;
int32_t date;
} __attribute__((packed));
#define MEM_E820_ENTRIES_NUM 48
#define MEM_E820T_USABLE 1
#define MEM_E820T_RESERVED 2
#define MEM_E820T_ACPI 3
#define MEM_E820T_ACPI_NVS 4
#define MEM_E820T_BAD_MEM 5
#define MEM_E820T_PERM_MEM 7
struct CMemE820 {
uint8_t *base;
int64_t len;
uint8_t type, pad[3];
} __attribute__((packed));
struct CGDTEntry {
uint64_t lo, hi;
} __attribute__((packed));
#define MP_PROCESSORS_NUM 128
struct CGDT {
struct CGDTEntry null;
struct CGDTEntry boot_ds;
struct CGDTEntry boot_cs;
struct CGDTEntry cs32;
struct CGDTEntry cs64;
struct CGDTEntry cs64_ring3;
struct CGDTEntry ds;
struct CGDTEntry ds_ring3;
struct CGDTEntry tr[MP_PROCESSORS_NUM];
struct CGDTEntry tr_ring3[MP_PROCESSORS_NUM];
} __attribute__((packed));
struct CSysLimitBase {
uint16_t limit;
uint8_t *base;
} __attribute__((packed));
struct CKernel {
struct CZXE h;
uint32_t jmp;
uint32_t boot_src;
uint32_t boot_blk;
uint32_t boot_patch_table_base;
uint32_t sys_run_level;
struct CDate compile_time;
// U0 start
uint32_t boot_base;
uint16_t mem_E801[2];
struct CMemE820 mem_E820[MEM_E820_ENTRIES_NUM];
uint64_t mem_physical_space;
struct CSysLimitBase sys_gdt_ptr;
uint16_t sys_pci_buses;
struct CGDT sys_gdt __attribute__((aligned(16)));
uint64_t sys_framebuffer_addr;
uint64_t sys_framebuffer_width;
uint64_t sys_framebuffer_height;
uint64_t sys_framebuffer_pitch;
uint8_t sys_framebuffer_bpp;
uint64_t sys_smbios_entry;
uint32_t sys_disk_uuid_a;
uint16_t sys_disk_uuid_b;
uint16_t sys_disk_uuid_c;
uint8_t sys_disk_uuid_d[8];
uint32_t sys_boot_stack;
} __attribute__((packed));
#define BOOT_SRC_RAM 2
#define BOOT_SRC_HDD 3
#define BOOT_SRC_DVD 4
#define RLF_16BIT 0b001
#define RLF_VESA 0b010
#define RLF_32BIT 0b100
extern symbol trampoline, trampoline_end;
struct E801 {
size_t lowermem;
size_t uppermem;
};
static struct E801 get_E801(void) {
struct E801 E801 = {0};
for (size_t i = 0; i < memmap_request.response->entry_count; i++) {
struct limine_memmap_entry *entry = memmap_request.response->entries[i];
if (entry->type == LIMINE_MEMMAP_USABLE) {
if (entry->base == 0x100000) {
if (entry->length > 0xf00000) {
E801.lowermem = 0x3c00;
} else {
E801.lowermem = entry->length / 1024;
}
}
if (entry->base <= 0x1000000 && entry->base + entry->length > 0x1000000) {
E801.uppermem = ((entry->length - (0x1000000 - entry->base)) / 1024) / 64;
}
}
}
return E801;
}
void _start(void) {
printf("ZealBooter prekernel\n");
printf("____________________\n\n");
idt_init();
struct limine_file *module_kernel = module_request.response->modules[0];
struct CKernel *kernel = module_kernel->address;
const size_t trampoline_size = (uintptr_t)trampoline_end - (uintptr_t)trampoline;
const size_t boot_stack_size = 32768;
const size_t final_size = align_up_u64(module_kernel->size + trampoline_size, 16) + boot_stack_size;
uintptr_t final_address = (uintptr_t)-1;
for (size_t i = 0; i < memmap_request.response->entry_count; i++) {
struct limine_memmap_entry *entry = memmap_request.response->entries[i];
if (entry->type != LIMINE_MEMMAP_USABLE) {
continue;
}
if (entry->length >= final_size) {
final_address = entry->base;
break;
}
}
if (final_address == (uintptr_t)-1) {
printf("ERROR: could not find valid final address");
for (;;) { asm("hlt"); }
}
printf("final_address: 0x%X\n", final_address);
struct limine_framebuffer *fb = framebuffer_request.response->framebuffers[0];
kernel->sys_framebuffer_pitch = fb->pitch;
kernel->sys_framebuffer_width = fb->width;
kernel->sys_framebuffer_height = fb->height;
kernel->sys_framebuffer_bpp = fb->bpp;
kernel->sys_framebuffer_addr = (uintptr_t)fb->address - hhdm_request.response->offset;
void *entry_point; // to CORE0_32BIT_INIT
for (uint64_t *p = (uint64_t *)kernel; ; p++) {
if (*p != 0xaa23c08ed10bd4d7) {
continue;
}
p++;
if (*p != 0xf6ceba7d4b74179a) {
continue;
}
p++;
entry_point = p;
break;
}
entry_point -= (uintptr_t)module_kernel->address;
entry_point += final_address;
printf("entry_point: 0x%X\n", entry_point);
if (module_kernel->media_type == LIMINE_MEDIA_TYPE_OPTICAL)
kernel->boot_src = BOOT_SRC_DVD;
else if (module_kernel->media_type == LIMINE_MEDIA_TYPE_GENERIC)
kernel->boot_src = BOOT_SRC_HDD;
else
kernel->boot_src = BOOT_SRC_RAM;
kernel->boot_blk = 0;
kernel->boot_patch_table_base = (uintptr_t)kernel + kernel->h.patch_table_offset;
kernel->boot_patch_table_base -= (uintptr_t)module_kernel->address;
kernel->boot_patch_table_base += final_address;
printf("kernel->boot_patch_table_base: 0x%X\n", kernel->boot_patch_table_base);
kernel->sys_run_level = RLF_VESA | RLF_16BIT | RLF_32BIT;
kernel->boot_base = (uintptr_t)&kernel->jmp - (uintptr_t)module_kernel->address;
kernel->boot_base += final_address;
printf("kernel->boot_base: 0x%X\n", kernel->boot_base);
kernel->sys_gdt_ptr.limit = sizeof(kernel->sys_gdt) - 1;
kernel->sys_gdt_ptr.base = (void *)&kernel->sys_gdt - (uintptr_t)module_kernel->address;
kernel->sys_gdt_ptr.base += final_address;
printf("kernel->sys_gdt_ptr.limit: 0x%X\n", kernel->sys_gdt_ptr.limit);
printf("kernel->sys_gdt_ptr.base: 0x%X\n", kernel->sys_gdt_ptr.base);
kernel->sys_pci_buses = 256;
struct E801 E801 = get_E801();
kernel->mem_E801[0] = E801.lowermem;
kernel->mem_E801[1] = E801.uppermem;
kernel->mem_physical_space = 0;
printf("memory map:\n");
for (size_t i = 0; i < memmap_request.response->entry_count; i++) {
struct limine_memmap_entry *entry = memmap_request.response->entries[i];
int our_type;
printf(" ");
switch (entry->type) {
case LIMINE_MEMMAP_BOOTLOADER_RECLAIMABLE:
case LIMINE_MEMMAP_KERNEL_AND_MODULES:
case LIMINE_MEMMAP_USABLE:
our_type = MEM_E820T_USABLE;
printf(" USABLE: ");
break;
case LIMINE_MEMMAP_ACPI_RECLAIMABLE:
our_type = MEM_E820T_ACPI;
printf(" ACPI: ");
break;
case LIMINE_MEMMAP_ACPI_NVS:
our_type = MEM_E820T_ACPI_NVS;
printf(" NVS: ");
break;
case LIMINE_MEMMAP_BAD_MEMORY:
our_type = MEM_E820T_BAD_MEM;
printf(" BAD: ");
break;
case LIMINE_MEMMAP_RESERVED:
default:
our_type = MEM_E820T_RESERVED;
printf("RESERVED: ");
break;
}
kernel->mem_E820[i].base = (void *)entry->base;
kernel->mem_E820[i].len = entry->length;
kernel->mem_E820[i].type = our_type;
if (kernel->mem_physical_space < entry->base + entry->length) {
kernel->mem_physical_space = entry->base + entry->length;
}
printf("0x%08X-0x%08X", entry->base, entry->base + entry->length - 1);
if (i % 3 == 0)
{
printf("\n");
}
}
printf("\n");
kernel->mem_E820[memmap_request.response->entry_count].type = 0;
kernel->mem_physical_space = align_up_u64(kernel->mem_physical_space, 0x200000);
void *sys_gdt_ptr = (void *)&kernel->sys_gdt_ptr - (uintptr_t)module_kernel->address;
sys_gdt_ptr += final_address;
printf("sys_gdt_ptr: 0x%X\n", sys_gdt_ptr);
void *sys_smbios_entry = smbios_request.response->entry_32;
if (sys_smbios_entry != NULL) {
kernel->sys_smbios_entry = (uintptr_t)sys_smbios_entry - hhdm_request.response->offset;
}
kernel->sys_disk_uuid_a = module_kernel->gpt_disk_uuid.a;
kernel->sys_disk_uuid_b = module_kernel->gpt_disk_uuid.b;
kernel->sys_disk_uuid_c = module_kernel->gpt_disk_uuid.c;
memcpy(kernel->sys_disk_uuid_d, module_kernel->gpt_disk_uuid.d, sizeof(struct limine_uuid));
void *const trampoline_phys = (void *)final_address + module_kernel->size;
printf("trampoline_phys: 0x%X\n", trampoline_phys);
const uintptr_t boot_stack = final_address + final_size;
printf("boot_stack: 0x%X\n", boot_stack);
kernel->sys_boot_stack = boot_stack;
memcpy(trampoline_phys, trampoline, trampoline_size);
memcpy((void *)final_address, kernel, module_kernel->size);
// printf("\nDEBUG: halting."); for (;;);
asm volatile (
"jmp *%0"
:
: "a"(trampoline_phys), "b"(entry_point),
"c"(sys_gdt_ptr), "d"(boot_stack),
"S"(kernel->boot_patch_table_base), "D"(kernel->boot_base)
: "memory");
__builtin_unreachable();
}