linux_dsm_epyc7002/arch/x86/boot/tools/build.c
Matt Fleming b8ff87a615 x86/efi: Firmware agnostic handover entry points
The EFI handover code only works if the "bitness" of the firmware and
the kernel match, i.e. 64-bit firmware and 64-bit kernel - it is not
possible to mix the two. This goes against the tradition that a 32-bit
kernel can be loaded on a 64-bit BIOS platform without having to do
anything special in the boot loader. Linux distributions, for one thing,
regularly run only 32-bit kernels on their live media.

Despite having only one 'handover_offset' field in the kernel header,
EFI boot loaders use two separate entry points to enter the kernel based
on the architecture the boot loader was compiled for,

    (1) 32-bit loader: handover_offset
    (2) 64-bit loader: handover_offset + 512

Since we already have two entry points, we can leverage them to infer
the bitness of the firmware we're running on, without requiring any boot
loader modifications, by making (1) and (2) valid entry points for both
CONFIG_X86_32 and CONFIG_X86_64 kernels.

To be clear, a 32-bit boot loader will always use (1) and a 64-bit boot
loader will always use (2). It's just that, if a single kernel image
supports (1) and (2) that image can be used with both 32-bit and 64-bit
boot loaders, and hence both 32-bit and 64-bit EFI.

(1) and (2) must be 512 bytes apart at all times, but that is already
part of the boot ABI and we could never change that delta without
breaking existing boot loaders anyhow.

Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-03-04 21:25:06 +00:00

413 lines
12 KiB
C

/*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 1997 Martin Mares
* Copyright (C) 2007 H. Peter Anvin
*/
/*
* This file builds a disk-image from three different files:
*
* - setup: 8086 machine code, sets up system parm
* - system: 80386 code for actual system
* - zoffset.h: header with ZO_* defines
*
* It does some checking that all files are of the correct type, and writes
* the result to the specified destination, removing headers and padding to
* the right amount. It also writes some system data to stdout.
*/
/*
* Changes by tytso to allow root device specification
* High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
* Cross compiling fixes by Gertjan van Wingerde, July 1996
* Rewritten by Martin Mares, April 1997
* Substantially overhauled by H. Peter Anvin, April 2007
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <tools/le_byteshift.h>
typedef unsigned char u8;
typedef unsigned short u16;
typedef unsigned int u32;
#define DEFAULT_MAJOR_ROOT 0
#define DEFAULT_MINOR_ROOT 0
#define DEFAULT_ROOT_DEV (DEFAULT_MAJOR_ROOT << 8 | DEFAULT_MINOR_ROOT)
/* Minimal number of setup sectors */
#define SETUP_SECT_MIN 5
#define SETUP_SECT_MAX 64
/* This must be large enough to hold the entire setup */
u8 buf[SETUP_SECT_MAX*512];
int is_big_kernel;
#define PECOFF_RELOC_RESERVE 0x20
unsigned long efi32_stub_entry;
unsigned long efi64_stub_entry;
unsigned long efi_pe_entry;
unsigned long startup_64;
/*----------------------------------------------------------------------*/
static const u32 crctab32[] = {
0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
0x2d02ef8d
};
static u32 partial_crc32_one(u8 c, u32 crc)
{
return crctab32[(crc ^ c) & 0xff] ^ (crc >> 8);
}
static u32 partial_crc32(const u8 *s, int len, u32 crc)
{
while (len--)
crc = partial_crc32_one(*s++, crc);
return crc;
}
static void die(const char * str, ...)
{
va_list args;
va_start(args, str);
vfprintf(stderr, str, args);
fputc('\n', stderr);
exit(1);
}
static void usage(void)
{
die("Usage: build setup system zoffset.h image");
}
#ifdef CONFIG_EFI_STUB
static void update_pecoff_section_header(char *section_name, u32 offset, u32 size)
{
unsigned int pe_header;
unsigned short num_sections;
u8 *section;
pe_header = get_unaligned_le32(&buf[0x3c]);
num_sections = get_unaligned_le16(&buf[pe_header + 6]);
#ifdef CONFIG_X86_32
section = &buf[pe_header + 0xa8];
#else
section = &buf[pe_header + 0xb8];
#endif
while (num_sections > 0) {
if (strncmp((char*)section, section_name, 8) == 0) {
/* section header size field */
put_unaligned_le32(size, section + 0x8);
/* section header vma field */
put_unaligned_le32(offset, section + 0xc);
/* section header 'size of initialised data' field */
put_unaligned_le32(size, section + 0x10);
/* section header 'file offset' field */
put_unaligned_le32(offset, section + 0x14);
break;
}
section += 0x28;
num_sections--;
}
}
static void update_pecoff_setup_and_reloc(unsigned int size)
{
u32 setup_offset = 0x200;
u32 reloc_offset = size - PECOFF_RELOC_RESERVE;
u32 setup_size = reloc_offset - setup_offset;
update_pecoff_section_header(".setup", setup_offset, setup_size);
update_pecoff_section_header(".reloc", reloc_offset, PECOFF_RELOC_RESERVE);
/*
* Modify .reloc section contents with a single entry. The
* relocation is applied to offset 10 of the relocation section.
*/
put_unaligned_le32(reloc_offset + 10, &buf[reloc_offset]);
put_unaligned_le32(10, &buf[reloc_offset + 4]);
}
static void update_pecoff_text(unsigned int text_start, unsigned int file_sz)
{
unsigned int pe_header;
unsigned int text_sz = file_sz - text_start;
pe_header = get_unaligned_le32(&buf[0x3c]);
/* Size of image */
put_unaligned_le32(file_sz, &buf[pe_header + 0x50]);
/*
* Size of code: Subtract the size of the first sector (512 bytes)
* which includes the header.
*/
put_unaligned_le32(file_sz - 512, &buf[pe_header + 0x1c]);
/*
* Address of entry point for PE/COFF executable
*/
put_unaligned_le32(text_start + efi_pe_entry, &buf[pe_header + 0x28]);
update_pecoff_section_header(".text", text_start, text_sz);
}
static int reserve_pecoff_reloc_section(int c)
{
/* Reserve 0x20 bytes for .reloc section */
memset(buf+c, 0, PECOFF_RELOC_RESERVE);
return PECOFF_RELOC_RESERVE;
}
static void efi_stub_defaults(void)
{
/* Defaults for old kernel */
#ifdef CONFIG_X86_32
efi_pe_entry = 0x10;
#else
efi_pe_entry = 0x210;
startup_64 = 0x200;
#endif
}
static void efi_stub_entry_update(void)
{
unsigned long addr = efi32_stub_entry;
#ifdef CONFIG_X86_64
/* Yes, this is really how we defined it :( */
addr = efi64_stub_entry - 0x200;
#endif
#ifdef CONFIG_EFI_MIXED
if (efi32_stub_entry != addr)
die("32-bit and 64-bit EFI entry points do not match\n");
#endif
put_unaligned_le32(addr, &buf[0x264]);
}
#else
static inline void update_pecoff_setup_and_reloc(unsigned int) {}
static inline void update_pecoff_text(unsigned int, unsigned int) {}
static inline void efi_stub_defaults(void) {}
static inline void efi_stup_entry_update(void) {}
static inline int reserve_pecoff_reloc_section(int c)
{
return 0;
}
#endif /* CONFIG_EFI_STUB */
/*
* Parse zoffset.h and find the entry points. We could just #include zoffset.h
* but that would mean tools/build would have to be rebuilt every time. It's
* not as if parsing it is hard...
*/
#define PARSE_ZOFS(p, sym) do { \
if (!strncmp(p, "#define ZO_" #sym " ", 11+sizeof(#sym))) \
sym = strtoul(p + 11 + sizeof(#sym), NULL, 16); \
} while (0)
static void parse_zoffset(char *fname)
{
FILE *file;
char *p;
int c;
file = fopen(fname, "r");
if (!file)
die("Unable to open `%s': %m", fname);
c = fread(buf, 1, sizeof(buf) - 1, file);
if (ferror(file))
die("read-error on `zoffset.h'");
fclose(file);
buf[c] = 0;
p = (char *)buf;
while (p && *p) {
PARSE_ZOFS(p, efi32_stub_entry);
PARSE_ZOFS(p, efi64_stub_entry);
PARSE_ZOFS(p, efi_pe_entry);
PARSE_ZOFS(p, startup_64);
p = strchr(p, '\n');
while (p && (*p == '\r' || *p == '\n'))
p++;
}
}
int main(int argc, char ** argv)
{
unsigned int i, sz, setup_sectors;
int c;
u32 sys_size;
struct stat sb;
FILE *file, *dest;
int fd;
void *kernel;
u32 crc = 0xffffffffUL;
efi_stub_defaults();
if (argc != 5)
usage();
parse_zoffset(argv[3]);
dest = fopen(argv[4], "w");
if (!dest)
die("Unable to write `%s': %m", argv[4]);
/* Copy the setup code */
file = fopen(argv[1], "r");
if (!file)
die("Unable to open `%s': %m", argv[1]);
c = fread(buf, 1, sizeof(buf), file);
if (ferror(file))
die("read-error on `setup'");
if (c < 1024)
die("The setup must be at least 1024 bytes");
if (get_unaligned_le16(&buf[510]) != 0xAA55)
die("Boot block hasn't got boot flag (0xAA55)");
fclose(file);
c += reserve_pecoff_reloc_section(c);
/* Pad unused space with zeros */
setup_sectors = (c + 511) / 512;
if (setup_sectors < SETUP_SECT_MIN)
setup_sectors = SETUP_SECT_MIN;
i = setup_sectors*512;
memset(buf+c, 0, i-c);
update_pecoff_setup_and_reloc(i);
/* Set the default root device */
put_unaligned_le16(DEFAULT_ROOT_DEV, &buf[508]);
printf("Setup is %d bytes (padded to %d bytes).\n", c, i);
/* Open and stat the kernel file */
fd = open(argv[2], O_RDONLY);
if (fd < 0)
die("Unable to open `%s': %m", argv[2]);
if (fstat(fd, &sb))
die("Unable to stat `%s': %m", argv[2]);
sz = sb.st_size;
printf("System is %d kB\n", (sz+1023)/1024);
kernel = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0);
if (kernel == MAP_FAILED)
die("Unable to mmap '%s': %m", argv[2]);
/* Number of 16-byte paragraphs, including space for a 4-byte CRC */
sys_size = (sz + 15 + 4) / 16;
/* Patch the setup code with the appropriate size parameters */
buf[0x1f1] = setup_sectors-1;
put_unaligned_le32(sys_size, &buf[0x1f4]);
update_pecoff_text(setup_sectors * 512, sz + i + ((sys_size * 16) - sz));
efi_stub_entry_update();
crc = partial_crc32(buf, i, crc);
if (fwrite(buf, 1, i, dest) != i)
die("Writing setup failed");
/* Copy the kernel code */
crc = partial_crc32(kernel, sz, crc);
if (fwrite(kernel, 1, sz, dest) != sz)
die("Writing kernel failed");
/* Add padding leaving 4 bytes for the checksum */
while (sz++ < (sys_size*16) - 4) {
crc = partial_crc32_one('\0', crc);
if (fwrite("\0", 1, 1, dest) != 1)
die("Writing padding failed");
}
/* Write the CRC */
printf("CRC %x\n", crc);
put_unaligned_le32(crc, buf);
if (fwrite(buf, 1, 4, dest) != 4)
die("Writing CRC failed");
/* Catch any delayed write failures */
if (fclose(dest))
die("Writing image failed");
close(fd);
/* Everything is OK */
return 0;
}