First step of moving bootloader to C++

2019-02-03 01:38:12 -08:00
parent a71af1be96
commit 579f6f64e6
15 changed files with 71 additions and 67 deletions
--- a/src/boot/main.cpp
+++ b/src/boot/main.cpp
@@ -0,0 +1,175 @@
+#include <stdalign.h>
+#include <stddef.h>
+
+#include <efi/efi.h>
+
+#include "console.h"
+#include "guids.h"
+#include "kernel_data.h"
+#include "loader.h"
+#include "memory.h"
+#include "utility.h"
+
+#ifndef GIT_VERSION_WIDE
+#define GIT_VERSION_WIDE L"no version"
+#endif
+
+#define KERNEL_HEADER_MAGIC   0x600db007
+#define KERNEL_HEADER_VERSION 1
+
+#pragma pack(push, 1)
+struct kernel_header {
+	uint32_t magic;
+	uint16_t version;
+	uint16_t length;
+
+	uint8_t major;
+	uint8_t minor;
+	uint16_t patch;
+	uint32_t gitsha;
+};
+#pragma pack(pop)
+
+using kernel_entry = void (*)(popcorn_data *);
+
+extern "C" EFI_STATUS
+efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *system_table)
+{
+	EFI_STATUS status;
+	EFI_BOOT_SERVICES *bootsvc = system_table->BootServices;
+	EFI_RUNTIME_SERVICES *runsvc = system_table->RuntimeServices;
+
+	// When checking console initialization, use CHECK_EFI_STATUS_OR_RETURN
+	// because we can't be sure if the console was fully set up
+	status = con_initialize(system_table, GIT_VERSION_WIDE);
+	CHECK_EFI_STATUS_OR_RETURN(status, "con_initialize");
+	// From here on out, we can use CHECK_EFI_STATUS_OR_FAIL instead
+
+	memory_init_pointer_fixup(bootsvc, runsvc);
+
+	// Find ACPI tables. Ignore ACPI 1.0 if a 2.0 table is found.
+	//
+	void *acpi_table = NULL;
+	for (size_t i=0; i<system_table->NumberOfTableEntries; ++i) {
+		EFI_CONFIGURATION_TABLE *efi_table = &system_table->ConfigurationTable[i];
+		if (is_guid(&efi_table->VendorGuid, &guid_acpi2)) {
+			acpi_table = efi_table->VendorTable;
+			break;
+		} else if (is_guid(&efi_table->VendorGuid, &guid_acpi1)) {
+			// Mark a v1 table with the LSB high
+			acpi_table = (void *)((intptr_t)efi_table->VendorTable | 0x1);
+		}
+	}
+
+	// Compute necessary number of data pages
+	//
+	size_t data_length = 0;
+	status = memory_get_map_length(bootsvc, &data_length);
+	CHECK_EFI_STATUS_OR_FAIL(status);
+
+	size_t header_size = sizeof(popcorn_data);
+	const size_t header_align = alignof(popcorn_data);
+	if (header_size % header_align)
+		header_size += header_align - (header_size % header_align);
+
+	data_length += header_size;
+
+
+	// Load the kernel image from disk and check it
+	//
+	con_printf(L"Loading kernel into memory...\r\n");
+
+	struct loader_data load;
+	load.data_length = data_length;
+	status = loader_load_kernel(bootsvc, &load);
+	CHECK_EFI_STATUS_OR_FAIL(status);
+
+	con_printf(L"    %u image bytes at 0x%x\r\n", load.kernel_length, load.kernel);
+	con_printf(L"    %u initrd bytes at 0x%x\r\n", load.initrd_length, load.initrd);
+	con_printf(L"    %u data bytes at 0x%x\r\n", load.data_length, load.data);
+
+	struct kernel_header *version = (struct kernel_header *)load.kernel;
+	if (version->magic != KERNEL_HEADER_MAGIC) {
+		con_printf(L"    bad magic %x\r\n", version->magic);
+		CHECK_EFI_STATUS_OR_FAIL(EFI_CRC_ERROR);
+	}
+
+	con_printf(L"    Kernel version %d.%d.%d %x%s\r\n",
+			version->major, version->minor, version->patch, version->gitsha & 0x0fffffff,
+			version->gitsha & 0xf0000000 ? "*" : "");
+	con_printf(L"    Entrypoint 0x%x\r\n", load.kernel_entry);
+
+	kernel_entry kernel_main =
+		reinterpret_cast<kernel_entry>(load.kernel_entry);
+	memory_mark_pointer_fixup((void **)&kernel_main);
+
+	// Set up the kernel data pages to pass to the kernel
+	//
+	struct popcorn_data *data_header = (struct popcorn_data *)load.data; 
+	memory_mark_pointer_fixup((void **)&data_header);
+
+	data_header->magic = DATA_HEADER_MAGIC;
+	data_header->version = DATA_HEADER_VERSION;
+	data_header->length = sizeof(struct popcorn_data);
+
+	data_header->flags = 0;
+
+	data_header->initrd = load.initrd;
+	data_header->initrd_length = load.initrd_length;
+	memory_mark_pointer_fixup((void **)&data_header->initrd);
+
+	data_header->data = load.data;
+	data_header->data_length = load.data_length;
+	memory_mark_pointer_fixup((void **)&data_header->data);
+
+	data_header->memory_map = (EFI_MEMORY_DESCRIPTOR *)(data_header + 1);
+	memory_mark_pointer_fixup((void **)&data_header->memory_map);
+
+	data_header->runtime = runsvc;
+	memory_mark_pointer_fixup((void **)&data_header->runtime);
+
+	data_header->acpi_table = acpi_table;
+	memory_mark_pointer_fixup((void **)&data_header->acpi_table);
+
+	data_header->_reserved0 = 0;
+	data_header->_reserved1 = 0;
+
+	// Figure out the framebuffer (if any) and add that to the data header
+	//
+	status = con_get_framebuffer(
+			bootsvc, 
+			&data_header->frame_buffer,
+			&data_header->frame_buffer_length,
+			&data_header->hres,
+			&data_header->vres,
+			&data_header->rmask,
+			&data_header->gmask,
+			&data_header->bmask);
+	CHECK_EFI_STATUS_OR_FAIL(status);
+	memory_mark_pointer_fixup((void **)&data_header->frame_buffer);
+
+	// Save the memory map and tell the firmware we're taking control.
+	//
+	struct memory_map map;
+	map.length = (load.data_length - header_size);
+	map.entries =
+		reinterpret_cast<EFI_MEMORY_DESCRIPTOR *>(data_header->memory_map);
+
+	status = memory_get_map(bootsvc, &map);
+	CHECK_EFI_STATUS_OR_FAIL(status);
+
+	data_header->memory_map_length = map.length;
+	data_header->memory_map_desc_size = map.size;
+
+	// bootsvc->Stall(5000000);
+
+	status = bootsvc->ExitBootServices(image_handle, map.key);
+	CHECK_EFI_STATUS_OR_ASSERT(status, 0);
+
+	memory_virtualize(runsvc, &map);
+
+	// Hand control to the kernel
+	//
+	kernel_main(data_header);
+	return EFI_LOAD_ERROR;
+}