/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* Copyright (C) 2015 Kay Sievers <kay@vrfy.org>
*/
#include <efi.h>
#include <efilib.h>
#include "linux.h"
#include "util.h"
#define SETUP_MAGIC 0x53726448 /* "HdrS" */
struct SetupHeader {
UINT8 boot_sector[0x01f1];
UINT8 setup_secs;
UINT16 root_flags;
UINT32 sys_size;
UINT16 ram_size;
UINT16 video_mode;
UINT16 root_dev;
UINT16 signature;
UINT16 jump;
UINT32 header;
UINT16 version;
UINT16 su_switch;
UINT16 setup_seg;
UINT16 start_sys;
UINT16 kernel_ver;
UINT8 loader_id;
UINT8 load_flags;
UINT16 movesize;
UINT32 code32_start;
UINT32 ramdisk_start;
UINT32 ramdisk_len;
UINT32 bootsect_kludge;
UINT16 heap_end;
UINT8 ext_loader_ver;
UINT8 ext_loader_type;
UINT32 cmd_line_ptr;
UINT32 ramdisk_max;
UINT32 kernel_alignment;
UINT8 relocatable_kernel;
UINT8 min_alignment;
UINT16 xloadflags;
UINT32 cmdline_size;
UINT32 hardware_subarch;
UINT64 hardware_subarch_data;
UINT32 payload_offset;
UINT32 payload_length;
UINT64 setup_data;
UINT64 pref_address;
UINT32 init_size;
UINT32 handover_offset;
} __attribute__((packed));
#ifdef __x86_64__
typedef VOID(*handover_f)(VOID *image, EFI_SYSTEM_TABLE *table, struct SetupHeader *setup);
static inline VOID linux_efi_handover(EFI_HANDLE image, struct SetupHeader *setup) {
handover_f handover;
asm volatile ("cli");
handover = (handover_f)((UINTN)setup->code32_start + 512 + setup->handover_offset);
handover(image, ST, setup);
}
#else
typedef VOID(*handover_f)(VOID *image, EFI_SYSTEM_TABLE *table, struct SetupHeader *setup) __attribute__((regparm(0)));
static inline VOID linux_efi_handover(EFI_HANDLE image, struct SetupHeader *setup) {
handover_f handover;
handover = (handover_f)((UINTN)setup->code32_start + setup->handover_offset);
handover(image, ST, setup);
}
#endif
EFI_STATUS linux_exec(EFI_HANDLE *image,
CHAR8 *cmdline, UINTN cmdline_len,
UINTN linux_addr,
UINTN initrd_addr, UINTN initrd_size) {
struct SetupHeader *image_setup;
struct SetupHeader *boot_setup;
EFI_PHYSICAL_ADDRESS addr;
EFI_STATUS err;
image_setup = (struct SetupHeader *)(linux_addr);
if (image_setup->signature != 0xAA55 || image_setup->header != SETUP_MAGIC)
return EFI_LOAD_ERROR;
if (image_setup->version < 0x20b || !image_setup->relocatable_kernel)
return EFI_LOAD_ERROR;
addr = 0x3fffffff;
err = uefi_call_wrapper(BS->AllocatePages, 4, AllocateMaxAddress, EfiLoaderData,
EFI_SIZE_TO_PAGES(0x4000), &addr);
if (EFI_ERROR(err))
return err;
boot_setup = (struct SetupHeader *)(UINTN)addr;
ZeroMem(boot_setup, 0x4000);
CopyMem(boot_setup, image_setup, sizeof(struct SetupHeader));
boot_setup->loader_id = 0xff;
boot_setup->code32_start = (UINT32)linux_addr + (image_setup->setup_secs+1) * 512;
if (cmdline) {
addr = 0xA0000;
err = uefi_call_wrapper(BS->AllocatePages, 4, AllocateMaxAddress, EfiLoaderData,
EFI_SIZE_TO_PAGES(cmdline_len + 1), &addr);
if (EFI_ERROR(err))
return err;
CopyMem((VOID *)(UINTN)addr, cmdline, cmdline_len);
((CHAR8 *)addr)[cmdline_len] = 0;
boot_setup->cmd_line_ptr = (UINT32)addr;
}
boot_setup->ramdisk_start = (UINT32)initrd_addr;
boot_setup->ramdisk_len = (UINT32)initrd_size;
linux_efi_handover(image, boot_setup);
return EFI_LOAD_ERROR;
}