rulimine/stage23/lib/blib.c
2021-07-20 13:35:43 +02:00

156 lines
3.7 KiB
C

#include <stdint.h>
#include <stddef.h>
#include <stdarg.h>
#include <lib/libc.h>
#include <lib/blib.h>
#include <lib/print.h>
#include <lib/trace.h>
#include <lib/real.h>
#include <fs/file.h>
#include <mm/pmm.h>
#if uefi == 1
EFI_SYSTEM_TABLE *gST;
EFI_BOOT_SERVICES *gBS;
EFI_RUNTIME_SERVICES *gRT;
EFI_HANDLE efi_image_handle;
EFI_MEMORY_DESCRIPTOR *efi_mmap = NULL;
UINTN efi_mmap_size = 0, efi_desc_size = 0, efi_desc_ver = 0;
#endif
bool verbose = false;
bool parse_resolution(int *width, int *height, int *bpp, const char *buf) {
int res[3] = {0};
const char *first = buf;
for (int i = 0; i < 3; i++) {
const char *last;
int x = strtoui(first, &last, 10);
if (first == last)
break;
res[i] = x;
if (*last == 0)
break;
first = last + 1;
}
if (res[0] == 0 || res[1] == 0)
return false;
if (res[2] == 0)
res[2] = 32;
*width = res[0], *height = res[1], *bpp = res[2];
return true;
}
// This integer sqrt implementation has been adapted from:
// https://stackoverflow.com/questions/1100090/looking-for-an-efficient-integer-square-root-algorithm-for-arm-thumb2
uint64_t sqrt(uint64_t a_nInput) {
uint64_t op = a_nInput;
uint64_t res = 0;
uint64_t one = (uint64_t)1 << 62;
// "one" starts at the highest power of four <= than the argument.
while (one > op) {
one >>= 2;
}
while (one != 0) {
if (op >= res + one) {
op = op - (res + one);
res = res + 2 * one;
}
res >>= 1;
one >>= 2;
}
return res;
}
size_t get_trailing_zeros(uint64_t val) {
for (size_t i = 0; i < 64; i++) {
if ((val & 1) != 0) {
return i;
}
val >>= 1;
}
return 64;
}
#if uefi == 1
bool efi_boot_services_exited = false;
bool efi_exit_boot_services(void) {
EFI_STATUS status;
EFI_MEMORY_DESCRIPTOR tmp_mmap[1];
efi_mmap_size = sizeof(tmp_mmap);
UINTN mmap_key = 0;
uefi_call_wrapper(gBS->GetMemoryMap, 5,
&efi_mmap_size, tmp_mmap, &mmap_key, &efi_desc_size, &efi_desc_ver);
efi_mmap_size += 4096;
status = uefi_call_wrapper(gBS->FreePool, 1, efi_mmap);
if (status)
goto fail;
status = uefi_call_wrapper(gBS->AllocatePool, 3,
EfiLoaderData, efi_mmap_size, (void **)&efi_mmap);
if (status)
goto fail;
status = uefi_call_wrapper(gBS->GetMemoryMap, 5,
&efi_mmap_size, efi_mmap, &mmap_key, &efi_desc_size, &efi_desc_ver);
if (status)
goto fail;
// Be gone, UEFI!
status = uefi_call_wrapper(gBS->ExitBootServices, 2, efi_image_handle, mmap_key);
asm volatile ("cli" ::: "memory");
if (status)
goto fail;
pmm_reclaim_uefi_mem();
// Go through new EFI memmap and free up bootloader entries
size_t entry_count = efi_mmap_size / efi_desc_size;
for (size_t i = 0; i < entry_count; i++) {
EFI_MEMORY_DESCRIPTOR *entry = (void *)efi_mmap + i * efi_desc_size;
uint64_t base = entry->PhysicalStart;
uint64_t length = entry->NumberOfPages * 4096;
// Find for a match in the untouched memory map
for (size_t j = 0; j < untouched_memmap_entries; j++) {
if (untouched_memmap[j].type != MEMMAP_USABLE)
continue;
if (untouched_memmap[j].base == base && untouched_memmap[j].length == length) {
// It's a match!
entry->Type = EfiConventionalMemory;
break;
}
}
}
efi_boot_services_exited = true;
printv("efi: Exited boot services.\n");
return true;
fail:
panic("efi: Failed to exit boot services");
}
#endif