/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2021 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "ape/relocations.h"
#include "ape/sections.internal.h"
#include "libc/dce.h"
#include "libc/intrin/newbie.h"
#include "libc/intrin/weaken.h"
#include "libc/macros.h"
#include "libc/nt/efi.h"
#include "libc/nt/thunk/msabi.h"
#include "libc/runtime/e820.internal.h"
#include "libc/runtime/internal.h"
#include "libc/runtime/pc.internal.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#pragma GCC diagnostic ignored "-Warray-bounds"
#pragma GCC diagnostic ignored "-Wstringop-overflow"
#ifdef __x86_64__
/* TODO: Why can't we change CR3? Could it really need PML5T? */
/* TODO: Why does QEMU in UEFI mode take ten seconds to boot? */
struct EfiArgs {
char *Args[0x400 / sizeof(char *)];
char ArgBlock[0xC00];
};
static EFI_GUID kEfiLoadedImageProtocol = LOADED_IMAGE_PROTOCOL;
static EFI_GUID kEfiGraphicsOutputProtocol = GRAPHICS_OUTPUT_PROTOCOL;
static const EFI_GUID kEfiAcpi20TableGuid = ACPI_20_TABLE_GUID;
static const EFI_GUID kEfiAcpi10TableGuid = ACPI_10_TABLE_GUID;
extern const char vga_console[];
extern void _EfiPostboot(struct mman *, uint64_t *, uintptr_t, char **);
static void EfiInitVga(struct mman *mm, EFI_SYSTEM_TABLE *SystemTable) {
EFI_GRAPHICS_OUTPUT_PROTOCOL *GraphInfo;
EFI_GRAPHICS_OUTPUT_PROTOCOL_MODE *GraphMode;
EFI_PIXEL_BITMASK *PixelInfo;
unsigned vid_typ = PC_VIDEO_TEXT;
size_t bytes_per_pix = 0;
SystemTable->BootServices->LocateProtocol(&kEfiGraphicsOutputProtocol, NULL,
&GraphInfo);
GraphMode = GraphInfo->Mode;
switch (GraphMode->Info->PixelFormat) {
case PixelRedGreenBlueReserved8BitPerColor:
vid_typ = PC_VIDEO_RGBX8888;
bytes_per_pix = 4;
break;
case PixelBlueGreenRedReserved8BitPerColor:
vid_typ = PC_VIDEO_BGRX8888;
bytes_per_pix = 4;
break;
case PixelBitMask:
PixelInfo = &GraphMode->Info->PixelInformation;
switch (le32toh(PixelInfo->RedMask)) {
case 0x00FF0000U:
if (le32toh(PixelInfo->ReservedMask) >= 0x01000000U &&
le32toh(PixelInfo->GreenMask) == 0x0000FF00U &&
le32toh(PixelInfo->BlueMask) == 0x000000FFU) {
vid_typ = PC_VIDEO_BGRX8888;
bytes_per_pix = 4;
}
break;
case 0x000000FFU:
if (le32toh(PixelInfo->ReservedMask) >= 0x01000000U &&
le32toh(PixelInfo->GreenMask) == 0x0000FF00U &&
le32toh(PixelInfo->BlueMask) == 0x00FF0000U) {
vid_typ = PC_VIDEO_RGBX8888;
bytes_per_pix = 4;
}
break;
case 0x0000F800U:
if (le32toh(PixelInfo->ReservedMask) <= 0x0000FFFFU &&
le32toh(PixelInfo->GreenMask) == 0x000007E0U &&
le32toh(PixelInfo->BlueMask) == 0x0000001FU) {
vid_typ = PC_VIDEO_BGR565;
bytes_per_pix = 2;
}
break;
case 0x00007C00U:
if (le32toh(PixelInfo->ReservedMask) <= 0x0000FFFFU &&
le32toh(PixelInfo->GreenMask) == 0x000003E0U &&
le32toh(PixelInfo->BlueMask) == 0x0000001FU) {
vid_typ = PC_VIDEO_BGR555;
bytes_per_pix = 2;
}
break;
}
default:
notpossible;
}
if (!bytes_per_pix)
notpossible;
mm->pc_video_type = vid_typ;
mm->pc_video_stride = GraphMode->Info->PixelsPerScanLine * bytes_per_pix;
mm->pc_video_width = GraphMode->Info->HorizontalResolution;
mm->pc_video_height = GraphMode->Info->VerticalResolution;
mm->pc_video_framebuffer = GraphMode->FrameBufferBase;
mm->pc_video_framebuffer_size = GraphMode->FrameBufferSize;
mm->pc_video_curs_info.y = mm->pc_video_curs_info.x = 0;
SystemTable->BootServices->SetMem((void *)GraphMode->FrameBufferBase,
GraphMode->FrameBufferSize, 0);
}
static void EfiInitAcpi(struct mman *mm, EFI_SYSTEM_TABLE *SystemTable) {
void *rsdp1 = NULL, *rsdp2 = NULL;
uintptr_t n = SystemTable->NumberOfTableEntries, i;
EFI_CONFIGURATION_TABLE *tab;
for (i = 0, tab = SystemTable->ConfigurationTable; i < n; ++i, ++tab) {
EFI_GUID *guid = &tab->VendorGuid;
if (memcmp(guid, &kEfiAcpi20TableGuid, sizeof(EFI_GUID)) == 0) {
rsdp2 = tab->VendorTable;
} else if (memcmp(guid, &kEfiAcpi20TableGuid, sizeof(EFI_GUID)) == 0) {
rsdp1 = tab->VendorTable;
}
}
if (rsdp2) {
mm->pc_acpi_rsdp = (uintptr_t)rsdp2;
} else {
mm->pc_acpi_rsdp = (uintptr_t)rsdp1;
}
}
/**
* EFI Application Entrypoint.
*
* This entrypoint is mutually exclusive from WinMain since
* Windows apps and EFI apps use the same PE binary format.
* So if you want to trade away Windows so that you can use
* UEFI instead of the normal BIOS boot process, do this:
*
* __static_yoink("EfiMain");
* int main() { ... }
*
* You can use QEMU to test this, but please note that UEFI
* goes thousands of times slower than the normal BIOS boot
*
* qemu-system-x86_64 \
* -bios OVMF.fd \
* -nographic \
* -net none \
* -drive format=raw,file=fat:rw:o/tool/viz
* FS0:
* deathstar
*
* @see libc/dce.h
*/
__msabi EFI_STATUS EfiMain(EFI_HANDLE ImageHandle,
EFI_SYSTEM_TABLE *SystemTable) {
struct mman *mm;
uint32_t DescVersion;
uintptr_t i, j, MapSize;
struct EfiArgs *ArgBlock;
EFI_LOADED_IMAGE *ImgInfo;
EFI_MEMORY_DESCRIPTOR *Map, *Desc;
uint64_t Address;
uintptr_t Args, MapKey, DescSize;
uint64_t *pd, *pml4t, *pdt1, *pdt2, *pdpt1, *pdpt2;
const char16_t *CmdLine;
extern char os asm("__hostos");
os = _HOSTMETAL;
/*
* Allocates and clears PC-compatible memory and copies image. Marks the
* pages as EfiRuntimeServicesData, so that we can simply free up all
* EfiLoader... and EfiBootServices... pages later. The first page at
* address 0 is normally already allocated as EfiBootServicesData, so
* handle it separately.
*/
Address = 0;
SystemTable->BootServices->AllocatePages(
AllocateAddress, EfiRuntimeServicesData, 4096 / 4096, &Address);
Address = 4096;
SystemTable->BootServices->AllocatePages(
AllocateAddress, EfiRuntimeServicesData, (IMAGE_BASE_REAL - 4096) / 4096,
&Address);
Address = 0x79000;
SystemTable->BootServices->AllocatePages(
AllocateAddress, EfiRuntimeServicesData,
(0x7f000 - 0x79000 + sizeof(struct EfiArgs) + 4095) / 4096, &Address);
Address = IMAGE_BASE_PHYSICAL;
SystemTable->BootServices->AllocatePages(
AllocateAddress, EfiRuntimeServicesData,
((_end - __executable_start) + 4095) / 4096, &Address);
mm = __get_mm_phy();
SystemTable->BootServices->SetMem(mm, sizeof(*mm), 0);
SystemTable->BootServices->SetMem(
(void *)0x79000, 0x7f000 - 0x79000 + sizeof(struct EfiArgs), 0);
SystemTable->BootServices->CopyMem((void *)IMAGE_BASE_PHYSICAL,
__executable_start,
_end - __executable_start);
/*
* Converts UEFI shell arguments to argv.
*/
ArgBlock = (struct EfiArgs *)0x7f000;
SystemTable->BootServices->HandleProtocol(ImageHandle,
&kEfiLoadedImageProtocol, &ImgInfo);
CmdLine = (const char16_t *)ImgInfo->LoadOptions;
if (!CmdLine || !CmdLine[0])
CmdLine = u"BOOTX64.EFI";
Args = GetDosArgv(CmdLine, ArgBlock->ArgBlock, sizeof(ArgBlock->ArgBlock),
ArgBlock->Args, ARRAYLEN(ArgBlock->Args));
/*
* Gets information about our current video mode. Clears the screen.
* TODO: if needed, switch to a video mode that has a linear frame buffer
* type we support.
*/
if (_weaken(vga_console))
EfiInitVga(mm, SystemTable);
/*
* Gets a pointer to the ACPI RSDP.
*/
EfiInitAcpi(mm, SystemTable);
/*
* Asks UEFI which parts of our RAM we're allowed to use.
*/
Map = NULL;
MapSize = 0;
SystemTable->BootServices->GetMemoryMap(&MapSize, Map, &MapKey, &DescSize,
&DescVersion);
SystemTable->BootServices->AllocatePool(EfiLoaderData, MapSize, &Map);
MapSize *= 2;
SystemTable->BootServices->GetMemoryMap(&MapSize, Map, &MapKey, &DescSize,
&DescVersion);
for (j = i = 0, Desc = Map; i < MapSize / DescSize; ++i) {
switch (Desc->Type) {
case EfiLoaderCode:
case EfiLoaderData:
case EfiBootServicesCode:
case EfiBootServicesData:
if (Desc->PhysicalStart != 0)
break;
/* fallthrough */
case EfiConventionalMemory:
mm->e820[j].addr = Desc->PhysicalStart;
mm->e820[j].size = Desc->NumberOfPages * 4096;
mm->e820[j].type = kMemoryUsable;
++j;
}
Desc = (EFI_MEMORY_DESCRIPTOR *)((char *)Desc + DescSize);
}
SystemTable->BootServices->FreePool(Map);
/*
* Sets up page tables.
*/
pd = (uint64_t *)0x79000;
pdt1 = (uint64_t *)0x7b000;
pdt2 = (uint64_t *)0x7a000;
pdpt1 = (uint64_t *)0x7d000;
pdpt2 = (uint64_t *)0x7c000;
pml4t = (uint64_t *)0x7e000;
for (i = 0; i < 512; ++i) {
pd[i] = 0x1000 * i + PAGE_V + PAGE_RSRV + PAGE_RW;
}
pdt1[0] = (intptr_t)pd + PAGE_V + PAGE_RW;
pdt2[0] = (intptr_t)pd + PAGE_V + PAGE_RW;
pdpt1[0] = (intptr_t)pdt1 + PAGE_V + PAGE_RW;
pdpt2[0] = (intptr_t)pdt2 + PAGE_V + PAGE_RW;
pml4t[0] = (intptr_t)pdpt1 + PAGE_V + PAGE_RW;
pml4t[256] = (intptr_t)pdpt2 + PAGE_V + PAGE_RW;
/*
* Asks UEFI to handover control?
*/
SystemTable->BootServices->ExitBootServices(ImageHandle, MapKey);
/*
* Switches to copied image and launches program.
*/
_EfiPostboot(mm, pml4t, Args, ArgBlock->Args);
__builtin_unreachable();
}
#endif /* __x86_64__ */