1 /* ----------------------------------------------------------------------- *
3 * Copyright 2007-2008 H. Peter Anvin - All Rights Reserved
4 * Copyright 2009 Intel Corporation; author: H. Peter Anvin
6 * Permission is hereby granted, free of charge, to any person
7 * obtaining a copy of this software and associated documentation
8 * files (the "Software"), to deal in the Software without
9 * restriction, including without limitation the rights to use,
10 * copy, modify, merge, publish, distribute, sublicense, and/or
11 * sell copies of the Software, and to permit persons to whom
12 * the Software is furnished to do so, subject to the following
15 * The above copyright notice and this permission notice shall
16 * be included in all copies or substantial portions of the Software.
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
20 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
21 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
22 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
23 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
24 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
25 * OTHER DEALINGS IN THE SOFTWARE.
27 * ----------------------------------------------------------------------- */
32 * Functions that deal with the memory map of various objects
37 static struct syslinux_movelist *ml = NULL;
38 static struct syslinux_memmap *mmap = NULL, *amap = NULL;
39 static struct multiboot_header *mbh;
40 static addr_t mboot_high_water_mark = 0x100000;
43 * Note: although there is no such thing in the spec, at least Xen makes
44 * assumptions as to where in the memory space Grub would have loaded
45 * certain things. To support that, if "high" is set, then allocate this
46 * at an address strictly above any previous allocations.
48 * As a precaution, this also pads the data with zero up to the next
51 addr_t map_data(const void *data, size_t len, size_t align, int flags)
53 addr_t start = (flags & MAP_HIGH) ? mboot_high_water_mark : 0x2000;
54 addr_t pad = (flags & MAP_NOPAD) ? 0 : -len & (align - 1);
55 addr_t xlen = len + pad;
57 if (syslinux_memmap_find(amap, SMT_FREE, &start, &xlen, align) ||
58 syslinux_add_memmap(&amap, start, len + pad, SMT_ALLOC) ||
59 syslinux_add_movelist(&ml, start, (addr_t) data, len) ||
60 (pad && syslinux_add_memmap(&mmap, start + len, pad, SMT_ZERO))) {
61 printf("Cannot map %zu bytes\n", len + pad);
65 dprintf("Mapping 0x%08x bytes (%#x pad) at 0x%08x\n", len, pad, start);
67 if (start + len + pad > mboot_high_water_mark)
68 mboot_high_water_mark = start + len + pad;
73 addr_t map_string(const char *string)
78 return map_data(string, strlen(string) + 1, 1, 0);
84 * Note: mmap is the memory map (containing free and zeroed regions)
85 * needed by syslinux_shuffle_boot_pm(); amap is a map where we keep
86 * track ourselves which target memory ranges have already been
89 mmap = syslinux_memory_map();
90 amap = syslinux_dup_memmap(mmap);
92 error("Failed to allocate initial memory map!\n");
96 dprintf("Initial memory map:\n");
97 syslinux_dump_memmap(stdout, mmap);
103 int map_image(void *ptr, size_t len)
107 Elf32_Ehdr *eh = ptr;
114 * Search for the multiboot header...
117 for (i = 0; i < MULTIBOOT_SEARCH; i += 4) {
118 mbh = (struct multiboot_header *)((char *)ptr + i);
119 if (mbh->magic != MULTIBOOT_MAGIC)
121 if (mbh->magic + mbh->flags + mbh->checksum)
123 if (mbh->flags & MULTIBOOT_VIDEO_MODE)
125 else if (mbh->flags & MULTIBOOT_AOUT_KLUDGE)
130 if (i + mbh_len < len)
131 mbh_len = 0; /* Invalid... */
133 break; /* Found something... */
137 bad_flags = mbh->flags & (MULTIBOOT_UNSUPPORTED | MULTIBOOT_VIDEO_MODE);
139 printf("Unsupported Multiboot flags set: %#x\n", bad_flags);
144 if (len < sizeof(Elf32_Ehdr) ||
145 memcmp(eh->e_ident, "\x7f" "ELF\1\1\1", 6) ||
146 (eh->e_machine != EM_386 && eh->e_machine != EM_486 &&
147 eh->e_machine != EM_X86_64) ||
148 eh->e_version != EV_CURRENT ||
149 eh->e_ehsize < sizeof(Elf32_Ehdr) || eh->e_ehsize >= len ||
150 eh->e_phentsize < sizeof(Elf32_Phdr) ||
151 !eh->e_phnum || eh->e_phoff + eh->e_phentsize * eh->e_phnum > len)
152 eh = NULL; /* No valid ELF header found */
155 * Note: the Multiboot Specification implies that AOUT_KLUDGE should
156 * have precedence over the ELF header. However, Grub disagrees, and
157 * Grub is "the reference bootloader" for the Multiboot Specification.
158 * This is insane, since it makes the AOUT_KLUDGE bit functionally
159 * useless, but at least Solaris apparently depends on this behavior.
161 if (eh && !(opt.aout && mbh_len && (mbh->flags & MULTIBOOT_AOUT_KLUDGE))) {
162 regs.eip = eh->e_entry; /* Can be overridden further down... */
164 ph = (Elf32_Phdr *) (cptr + eh->e_phoff);
166 for (i = 0; i < eh->e_phnum; i++) {
167 if (ph->p_type == PT_LOAD || ph->p_type == PT_PHDR) {
169 * This loads at p_paddr, which matches Grub. However, if
170 * e_entry falls within the p_vaddr range of this PHDR, then
171 * adjust it to match the p_paddr range... this is how Grub
172 * behaves, so it's by definition correct (it doesn't have to
175 addr_t addr = ph->p_paddr;
176 addr_t msize = ph->p_memsz;
177 addr_t dsize = min(msize, ph->p_filesz);
179 if (eh->e_entry >= ph->p_vaddr
180 && eh->e_entry < ph->p_vaddr + msize)
181 regs.eip = eh->e_entry + (ph->p_paddr - ph->p_vaddr);
183 dprintf("Segment at 0x%08x data 0x%08x len 0x%08x\n",
186 if (syslinux_memmap_type(amap, addr, msize) != SMT_FREE) {
188 ("Memory segment at 0x%08x (len 0x%08x) is unavailable\n",
190 return -1; /* Memory region unavailable */
193 /* Mark this region as allocated in the available map */
194 if (syslinux_add_memmap(&amap, addr, msize, SMT_ALLOC)) {
195 error("Overlapping segments found in ELF header\n");
200 /* Data present region. Create a move entry for it. */
201 if (syslinux_add_movelist
202 (&ml, addr, (addr_t) cptr + ph->p_offset, dsize)) {
203 error("Failed to map PHDR data\n");
208 /* Zero-filled region. Mark as a zero region in the memory map. */
209 if (syslinux_add_memmap
210 (&mmap, addr + dsize, msize - dsize, SMT_ZERO)) {
211 error("Failed to map PHDR zero region\n");
215 if (addr + msize > mboot_high_water_mark)
216 mboot_high_water_mark = addr + msize;
218 /* Ignore this program header */
221 ph = (Elf32_Phdr *) ((char *)ph + eh->e_phentsize);
224 /* Load the ELF symbol table */
228 sh = (Elf32_Shdr *) ((char *)eh + eh->e_shoff);
230 len = eh->e_shentsize * eh->e_shnum;
232 * Align this, but don't pad -- in general this means a bunch of
233 * smaller sections gets packed into a single page.
235 addr = map_data(sh, len, 4096, MAP_HIGH | MAP_NOPAD);
237 error("Failed to map symbol table\n");
241 mbinfo.flags |= MB_INFO_ELF_SHDR;
242 mbinfo.syms.e.addr = addr;
243 mbinfo.syms.e.num = eh->e_shnum;
244 mbinfo.syms.e.size = eh->e_shentsize;
245 mbinfo.syms.e.shndx = eh->e_shstrndx;
247 for (i = 0; i < eh->e_shnum; i++) {
251 continue; /* Empty section */
252 if (sh[i].sh_flags & SHF_ALLOC)
253 continue; /* SHF_ALLOC sections should have PHDRs */
255 align = sh[i].sh_addralign ? sh[i].sh_addralign : 0;
256 addr = map_data((char *)ptr + sh[i].sh_offset, sh[i].sh_size,
259 error("Failed to map symbol section\n");
262 sh[i].sh_addr = addr;
265 } else if (mbh_len && (mbh->flags & MULTIBOOT_AOUT_KLUDGE)) {
267 * a.out kludge thing...
270 addr_t data_len, bss_len;
272 regs.eip = mbh->entry_addr;
274 data_ptr = (char *)mbh - (mbh->header_addr - mbh->load_addr);
275 data_len = mbh->load_end_addr - mbh->load_addr;
276 bss_len = mbh->bss_end_addr - mbh->load_end_addr;
278 if (syslinux_memmap_type(amap, mbh->load_addr, data_len + bss_len)
280 printf("Memory segment at 0x%08x (len 0x%08x) is unavailable\n",
281 mbh->load_addr, data_len + bss_len);
282 return -1; /* Memory region unavailable */
284 if (syslinux_add_memmap(&amap, mbh->load_addr,
285 data_len + bss_len, SMT_ALLOC)) {
286 error("Failed to claim a.out address space!\n");
290 if (syslinux_add_movelist(&ml, mbh->load_addr, (addr_t) data_ptr,
292 error("Failed to map a.out data\n");
296 if (syslinux_add_memmap
297 (&mmap, mbh->load_end_addr, bss_len, SMT_ZERO)) {
298 error("Failed to map a.out bss\n");
301 if (mbh->bss_end_addr > mboot_high_water_mark)
302 mboot_high_water_mark = mbh->bss_end_addr;
305 ("Invalid Multiboot image: neither ELF header nor a.out kludge found\n");
313 * Set up a stack. This isn't actually required by the spec, but it seems
314 * like a prudent thing to do. Also, put enough zeros at the top of the
315 * stack that something that looks for an ELF invocation record will know
318 static void mboot_map_stack(void)
322 if (syslinux_memmap_largest(amap, SMT_FREE, &start, &len) || len < 64)
323 return; /* Not much we can do, here... */
325 regs.esp = (start + len - 32) & ~15;
326 dprintf("Mapping stack at 0x%08x\n", regs.esp);
327 syslinux_add_memmap(&mmap, regs.esp, 32, SMT_ZERO);
330 void mboot_run(int bootflags)
334 dprintf("Running, eip = 0x%08x, ebx = 0x%08x\n", regs.eip, regs.ebx);
336 regs.eax = MULTIBOOT_VALID;
337 syslinux_shuffle_boot_pm(ml, mmap, bootflags, ®s);