[syslinux:master] mboot.c32: add ELF64 support for Multiboot1
syslinux-bot for Alex
barracuda72 at bk.ru
Sat Oct 10 11:00:02 PDT 2015
Commit-ID: 91463467e4633d7c29dfb98b4079c3c330fcde95
Gitweb: http://www.syslinux.org/commit/91463467e4633d7c29dfb98b4079c3c330fcde95
Author: Alex <barracuda72 at bk.ru>
AuthorDate: Sat, 10 Oct 2015 13:56:20 -0400
Committer: Gene Cumm <gene.cumm at gmail.com>
CommitDate: Sat, 10 Oct 2015 13:57:01 -0400
mboot.c32: add ELF64 support for Multiboot1
mboot.c32 lacks support for loading ELF64 binaries (supported by GRUB2,
for example). This is a trivial patch to add such feature.
[reflow some changes to fit ~80 columns; remove trailing whitespace
- gene.cumm at gmail.com]
Signed-off-by: Gene Cumm <gene.cumm at gmail.com>
---
com32/mboot/map.c | 123 ++++++++++++++++++++++++++++++++++++++++++++++++++++
com32/mboot/mboot.h | 1 +
2 files changed, 124 insertions(+)
diff --git a/com32/mboot/map.c b/com32/mboot/map.c
index 4b0baa2..97b5b5d 100644
--- a/com32/mboot/map.c
+++ b/com32/mboot/map.c
@@ -106,6 +106,11 @@ struct multiboot_header *map_image(void *ptr, size_t len)
Elf32_Ehdr *eh = ptr;
Elf32_Phdr *ph;
Elf32_Shdr *sh;
+
+ Elf64_Ehdr *eh64 = ptr;
+ Elf64_Phdr *ph64;
+ Elf64_Shdr *sh64;
+
unsigned int i, mbh_offset;
uint32_t bad_flags;
@@ -150,6 +155,18 @@ struct multiboot_header *map_image(void *ptr, size_t len)
!eh->e_phnum || eh->e_phoff + eh->e_phentsize * eh->e_phnum > len)
eh = NULL; /* No valid ELF header found */
+ /* Determine 64-bit images */
+ if ((eh != NULL) ||
+ len < sizeof(Elf64_Ehdr) ||
+ memcmp(eh64->e_ident, "\x7f" "ELF\2\1\1", 6) ||
+ (eh64->e_machine != EM_X86_64) ||
+ eh64->e_version != EV_CURRENT ||
+ eh64->e_ehsize < sizeof(Elf64_Ehdr) || eh64->e_ehsize >= len ||
+ eh64->e_phentsize < sizeof(Elf64_Phdr) ||
+ !eh64->e_phnum ||
+ eh64->e_phoff + eh64->e_phentsize * eh64->e_phnum > len)
+ eh64 = NULL; /* No valid ELF64 header found */
+
/* Is this a Solaris kernel? */
if (!set.solaris && eh && kernel_is_solaris(eh))
opt.solaris = true;
@@ -265,6 +282,112 @@ struct multiboot_header *map_image(void *ptr, size_t len)
sh[i].sh_addr = addr;
}
}
+ } else if (eh64 && !(opt.aout && mbh_len &&
+ (mbh->flags & MULTIBOOT_AOUT_KLUDGE))) {
+ /* Load 64-bit ELF */
+ regs.eip = eh64->e_entry; /* Can be overridden further down... */
+
+ ph64 = (Elf64_Phdr *) (cptr + eh64->e_phoff);
+
+ for (i = 0; i < eh64->e_phnum; i++) {
+ if (ph64->p_type == PT_LOAD || ph64->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 = ph64->p_paddr;
+ addr_t msize = ph64->p_memsz;
+ addr_t dsize = min(msize, ph64->p_filesz);
+
+ if (eh64->e_entry >= ph64->p_vaddr
+ && eh64->e_entry < ph64->p_vaddr + msize)
+ regs.eip = eh64->e_entry + (ph64->p_paddr - ph64->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 (ph64->p_filesz) {
+ /* Data present region. Create a move entry for it. */
+ if (syslinux_add_movelist
+ (&ml, addr, (addr_t) cptr + ph64->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 */
+ }
+
+ ph64 = (Elf64_Phdr *) ((char *)ph64 + eh64->e_phentsize);
+ }
+
+ /* Load the ELF symbol table */
+ if (eh64->e_shoff) {
+ addr_t addr, len;
+
+ sh64 = (Elf64_Shdr *) ((char *)eh64 + eh64->e_shoff);
+
+ len = eh64->e_shentsize * eh64->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(sh64, 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 = eh64->e_shnum;
+ mbinfo.syms.e.size = eh64->e_shentsize;
+ mbinfo.syms.e.shndx = eh64->e_shstrndx;
+
+ for (i = 0; i < eh64->e_shnum; i++) {
+ addr_t align;
+
+ if (!sh64[i].sh_size)
+ continue; /* Empty section */
+ if (sh64[i].sh_flags & SHF_ALLOC)
+ continue; /* SHF_ALLOC sections should have PHDRs */
+
+ align = sh64[i].sh_addralign ? sh64[i].sh_addralign : 0;
+ addr = map_data((char *)ptr + sh64[i].sh_offset,
+ sh64[i].sh_size, align, MAP_HIGH);
+ if (!addr) {
+ error("Failed to map symbol section\n");
+ return NULL;
+ }
+ sh64[i].sh_addr = addr;
+ }
+ }
} else if (mbh_len && (mbh->flags & MULTIBOOT_AOUT_KLUDGE)) {
/*
* a.out kludge thing...
diff --git a/com32/mboot/mboot.h b/com32/mboot/mboot.h
index da6ca2f..9f9e510 100644
--- a/com32/mboot/mboot.h
+++ b/com32/mboot/mboot.h
@@ -46,6 +46,7 @@
#include <minmax.h>
#include <sys/stat.h>
#include <elf.h>
+#include <sys/elf64.h>
#include <console.h>
#include <syslinux/loadfile.h>
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