/* ----------------------------------------------------------------------- *
*
* Copyright 2007-2008 H. Peter Anvin - All Rights Reserved
* Copyright 2009-2010 Intel Corporation; author: H. Peter Anvin
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom
* the Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall
* be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* ----------------------------------------------------------------------- */
/*
* map.c
*
* Functions that deal with the memory map of various objects
*/
#include "mboot.h"
static struct syslinux_movelist *ml = NULL;
static struct syslinux_memmap *mmap = NULL, *amap = NULL;
static addr_t mboot_high_water_mark = 0x100000;
/*
* Note: although there is no such thing in the spec, at least Xen makes
* assumptions as to where in the memory space Grub would have loaded
* certain things. To support that, if "high" is set, then allocate this
* at an address strictly above any previous allocations.
*
* As a precaution, this also pads the data with zero up to the next
* alignment datum.
*/
addr_t map_data(const void *data, size_t len, size_t align, int flags)
{
addr_t start = (flags & MAP_HIGH) ? mboot_high_water_mark : 0x2000;
addr_t pad = (flags & MAP_NOPAD) ? 0 : -len & (align - 1);
addr_t xlen = len + pad;
if (syslinux_memmap_find(amap, SMT_FREE, &start, &xlen, align) ||
syslinux_add_memmap(&amap, start, len + pad, SMT_ALLOC) ||
syslinux_add_movelist(&ml, start, (addr_t) data, len) ||
(pad && syslinux_add_memmap(&mmap, start + len, pad, SMT_ZERO))) {
printf("Cannot map %zu bytes\n", len + pad);
return 0;
}
dprintf("Mapping 0x%08x bytes (%#x pad) at 0x%08x\n", len, pad, start);
if (start + len + pad > mboot_high_water_mark)
mboot_high_water_mark = start + len + pad;
return start;
}
addr_t map_string(const char *string)
{
if (!string)
return 0;
else
return map_data(string, strlen(string) + 1, 1, 0);
}
int init_map(void)
{
/*
* Note: mmap is the memory map (containing free and zeroed regions)
* needed by syslinux_shuffle_boot_pm(); amap is a map where we keep
* track ourselves which target memory ranges have already been
* allocated.
*/
mmap = syslinux_memory_map();
amap = syslinux_dup_memmap(mmap);
if (!mmap || !amap) {
error("Failed to allocate initial memory map!\n");
return -1;
}
#if DEBUG
dprintf("Initial memory map:\n");
syslinux_dump_memmap(stdout, mmap);
#endif
return 0;
}
struct multiboot_header *map_image(void *ptr, size_t len)
{
struct multiboot_header *mbh;
int mbh_len;
char *cptr = ptr;
Elf32_Ehdr *eh = ptr;
Elf32_Phdr *ph;
Elf32_Shdr *sh;
unsigned int i, mbh_offset;
uint32_t bad_flags;
/*
* Search for the multiboot header...
*/
mbh_len = 0;
for (mbh_offset = 0; mbh_offset < MULTIBOOT_SEARCH; mbh_offset += 4) {
mbh = (struct multiboot_header *)((char *)ptr + mbh_offset);
if (mbh->magic != MULTIBOOT_MAGIC)
continue;
if (mbh->magic + mbh->flags + mbh->checksum)
continue;
if (mbh->flags & MULTIBOOT_VIDEO_MODE)
mbh_len = 48;
else if (mbh->flags & MULTIBOOT_AOUT_KLUDGE)
mbh_len = 32;
else
mbh_len = 12;
if (mbh_offset + mbh_len > len)
mbh_len = 0; /* Invalid... */
else
break; /* Found something... */
}
if (mbh_len) {
bad_flags = mbh->flags & MULTIBOOT_UNSUPPORTED;
if (bad_flags) {
printf("Unsupported Multiboot flags set: %#x\n", bad_flags);
return NULL;
}
}
if (len < sizeof(Elf32_Ehdr) ||
memcmp(eh->e_ident, "\x7f" "ELF\1\1\1", 6) ||
(eh->e_machine != EM_386 && eh->e_machine != EM_486 &&
eh->e_machine != EM_X86_64) ||
eh->e_version != EV_CURRENT ||
eh->e_ehsize < sizeof(Elf32_Ehdr) || eh->e_ehsize >= len ||
eh->e_phentsize < sizeof(Elf32_Phdr) ||
!eh->e_phnum || eh->e_phoff + eh->e_phentsize * eh->e_phnum > len)
eh = NULL; /* No valid ELF header found */
/* Is this a Solaris kernel? */
if (!set.solaris && eh && kernel_is_solaris(eh))
opt.solaris = true;
/*
* Note: the Multiboot Specification implies that AOUT_KLUDGE should
* have precedence over the ELF header. However, Grub disagrees, and
* Grub is "the reference bootloader" for the Multiboot Specification.
* This is insane, since it makes the AOUT_KLUDGE bit functionally
* useless, but at least Solaris apparently depends on this behavior.
*/
if (eh && !(opt.aout && mbh_len && (mbh->flags & MULTIBOOT_AOUT_KLUDGE))) {
regs.eip = eh->e_entry; /* Can be overridden further down... */
ph = (Elf32_Phdr *) (cptr + eh->e_phoff);
for (i = 0; i < eh->e_phnum; i++) {
if (ph->p_type == PT_LOAD || ph->p_type == PT_PHDR) {
/*
* This loads at p_paddr, which matches Grub. However, if
* e_entry falls within the p_vaddr range of this PHDR, then
* adjust it to match the p_paddr range... this is how Grub
* behaves, so it's by definition correct (it doesn't have to
* make sense...)
*/
addr_t addr = ph->p_paddr;
addr_t msize = ph->p_memsz;
addr_t dsize = min(msize, ph->p_filesz);
if (eh->e_entry >= ph->p_vaddr
&& eh->e_entry < ph->p_vaddr + msize)
regs.eip = eh->e_entry + (ph->p_paddr - ph->p_vaddr);
dprintf("Segment at 0x%08x data 0x%08x len 0x%08x\n",
addr, dsize, msize);
if (syslinux_memmap_type(amap, addr, msize) != SMT_FREE) {
printf
("Memory segment at 0x%08x (len 0x%08x) is unavailable\n",
addr, msize);
return NULL; /* Memory region unavailable */
}
/* Mark this region as allocated in the available map */
if (syslinux_add_memmap(&amap, addr, msize, SMT_ALLOC)) {
error("Overlapping segments found in ELF header\n");
return NULL;
}
if (ph->p_filesz) {
/* Data present region. Create a move entry for it. */
if (syslinux_add_movelist
(&ml, addr, (addr_t) cptr + ph->p_offset, dsize)) {
error("Failed to map PHDR data\n");
return NULL;
}
}
if (msize > dsize) {
/* Zero-filled region. Mark as a zero region in the memory map. */
if (syslinux_add_memmap
(&mmap, addr + dsize, msize - dsize, SMT_ZERO)) {
error("Failed to map PHDR zero region\n");
return NULL;
}
}
if (addr + msize > mboot_high_water_mark)
mboot_high_water_mark = addr + msize;
} else {
/* Ignore this program header */
}
ph = (Elf32_Phdr *) ((char *)ph + eh->e_phentsize);
}
/* Load the ELF symbol table */
if (eh->e_shoff) {
addr_t addr, len;
sh = (Elf32_Shdr *) ((char *)eh + eh->e_shoff);
len = eh->e_shentsize * eh->e_shnum;
/*
* Align this, but don't pad -- in general this means a bunch of
* smaller sections gets packed into a single page.
*/
addr = map_data(sh, len, 4096, MAP_HIGH | MAP_NOPAD);
if (!addr) {
error("Failed to map symbol table\n");
return NULL;
}
mbinfo.flags |= MB_INFO_ELF_SHDR;
mbinfo.syms.e.addr = addr;
mbinfo.syms.e.num = eh->e_shnum;
mbinfo.syms.e.size = eh->e_shentsize;
mbinfo.syms.e.shndx = eh->e_shstrndx;
for (i = 0; i < eh->e_shnum; i++) {
addr_t align;
if (!sh[i].sh_size)
continue; /* Empty section */
if (sh[i].sh_flags & SHF_ALLOC)
continue; /* SHF_ALLOC sections should have PHDRs */
align = sh[i].sh_addralign ? sh[i].sh_addralign : 0;
addr = map_data((char *)ptr + sh[i].sh_offset, sh[i].sh_size,
align, MAP_HIGH);
if (!addr) {
error("Failed to map symbol section\n");
return NULL;
}
sh[i].sh_addr = addr;
}
}
} else if (mbh_len && (mbh->flags & MULTIBOOT_AOUT_KLUDGE)) {
/*
* a.out kludge thing...
*/
char *data_ptr;
addr_t data_len, bss_len;
addr_t bss_addr;
regs.eip = mbh->entry_addr;
data_ptr = (char *)mbh - (mbh->header_addr - mbh->load_addr);
if (mbh->load_end_addr)
data_len = mbh->load_end_addr - mbh->load_addr;
else
data_len = len - mbh_offset + (mbh->header_addr - mbh->load_addr);
bss_addr = mbh->load_addr + data_len;
if (mbh->bss_end_addr)
bss_len = mbh->bss_end_addr - mbh->load_end_addr;
else
bss_len = 0;
if (syslinux_memmap_type(amap, mbh->load_addr, data_len + bss_len)
!= SMT_FREE) {
printf("Memory segment at 0x%08x (len 0x%08x) is unavailable\n",
mbh->load_addr, data_len + bss_len);
return NULL; /* Memory region unavailable */
}
if (syslinux_add_memmap(&amap, mbh->load_addr,
data_len + bss_len, SMT_ALLOC)) {
error("Failed to claim a.out address space!\n");
return NULL;
}
if (data_len)
if (syslinux_add_movelist(&ml, mbh->load_addr, (addr_t) data_ptr,
data_len)) {
error("Failed to map a.out data\n");
return NULL;
}
if (bss_len)
if (syslinux_add_memmap
(&mmap, bss_addr, bss_len, SMT_ZERO)) {
error("Failed to map a.out bss\n");
return NULL;
}
if (bss_addr + bss_len > mboot_high_water_mark)
mboot_high_water_mark = bss_addr + bss_len;
} else {
error
("Invalid Multiboot image: neither ELF header nor a.out kludge found\n");
return NULL;
}
return mbh;
}
/*
* Set up a stack. This isn't actually required by the spec, but it seems
* like a prudent thing to do. Also, put enough zeros at the top of the
* stack that something that looks for an ELF invocation record will know
* there isn't one.
*/
static void mboot_map_stack(void)
{
addr_t start, len;
if (syslinux_memmap_largest(amap, SMT_FREE, &start, &len) || len < 64)
return; /* Not much we can do, here... */
regs.esp = (start + len - 32) & ~15;
dprintf("Mapping stack at 0x%08x\n", regs.esp);
syslinux_add_memmap(&mmap, regs.esp, 32, SMT_ZERO);
}
void mboot_run(int bootflags)
{
mboot_map_stack();
dprintf("Running, eip = 0x%08x, ebx = 0x%08x\n", regs.eip, regs.ebx);
regs.eax = MULTIBOOT_VALID;
syslinux_shuffle_boot_pm(ml, mmap, bootflags, ®s);
}
