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arm-uboot: Make self-relocatable to allow loading at any address

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This commit is contained in:
Vladimir Serbinenko 2016-02-19 00:43:36 +01:00
parent 5bcb7d394c
commit 86ef66d977
7 changed files with 305 additions and 87 deletions
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313
util/grub-mkimagexx.c
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@ -86,6 +86,12 @@ struct fixup_block_list
#define ALIGN_ADDR(x) (ALIGN_UP((x), image_target->voidp_sizeof))
static int
is_relocatable (const struct grub_install_image_target_desc *image_target)
{
return image_target->id == IMAGE_EFI || image_target->id == IMAGE_UBOOT;
}
#ifdef MKIMAGE_ELF32
/*
@ -529,9 +535,9 @@ SUFFIX (relocate_symbols) (Elf_Ehdr *e, Elf_Shdr *sections,
}
else if (cur_index == STN_UNDEF)
{
if (sym->st_name && grub_strcmp (name, "__bss_start"))
if (sym->st_name && grub_strcmp (name, "__bss_start") == 0)
sym->st_value = bss_start;
else if (sym->st_name && grub_strcmp (name, "__end"))
else if (sym->st_name && grub_strcmp (name, "_end") == 0)
sym->st_value = end;
else if (sym->st_name)
grub_util_error ("undefined symbol %s", name);
@ -1008,7 +1014,8 @@ SUFFIX (relocate_addresses) (Elf_Ehdr *e, Elf_Shdr *sections,
grub_util_info (" ABS32:\toffset=%d\t(0x%08x)",
(int) sym_addr, (int) sym_addr);
/* Data will be naturally aligned */
sym_addr += 0x400;
if (image_target->id == IMAGE_EFI)
sym_addr += 0x400;
*target = grub_host_to_target32 (grub_target_to_host32 (*target) + sym_addr);
}
break;
@ -1194,25 +1201,45 @@ add_fixup_entry (struct fixup_block_list **cblock, grub_uint16_t type,
return current_address;
}
struct raw_reloc
{
struct raw_reloc *next;
grub_uint32_t offset;
enum raw_reloc_type {
RAW_RELOC_NONE = -1,
RAW_RELOC_32 = 0,
RAW_RELOC_MAX = 1,
} type;
};
struct translate_context
{
/* PE */
struct fixup_block_list *lst, *lst0;
Elf_Addr current_address;
/* Raw */
struct raw_reloc *raw_relocs;
};
static void
translate_reloc_start (struct translate_context *ctx)
translate_reloc_start (struct translate_context *ctx,
const struct grub_install_image_target_desc *image_target)
{
ctx->lst = ctx->lst0 = xmalloc (sizeof (*ctx->lst) + 2 * 0x1000);
memset (ctx->lst, 0, sizeof (*ctx->lst) + 2 * 0x1000);
ctx->current_address = 0;
grub_memset (ctx, 0, sizeof (*ctx));
if (image_target->id == IMAGE_EFI)
{
ctx->lst = ctx->lst0 = xmalloc (sizeof (*ctx->lst) + 2 * 0x1000);
memset (ctx->lst, 0, sizeof (*ctx->lst) + 2 * 0x1000);
ctx->current_address = 0;
}
}
static void
translate_relocation (struct translate_context *ctx,
Elf_Addr addr,
Elf_Addr info,
const struct grub_install_image_target_desc *image_target)
translate_relocation_pe (struct translate_context *ctx,
Elf_Addr addr,
Elf_Addr info,
const struct grub_install_image_target_desc *image_target)
{
/* Necessary to relocate only absolute addresses. */
switch (image_target->elf_target)
@ -1353,10 +1380,68 @@ translate_relocation (struct translate_context *ctx,
}
}
static enum raw_reloc_type
classify_raw_reloc (Elf_Addr info,
const struct grub_install_image_target_desc *image_target)
{
/* Necessary to relocate only absolute addresses. */
switch (image_target->elf_target)
{
case EM_ARM:
switch (ELF_R_TYPE (info))
{
case R_ARM_V4BX:
case R_ARM_JUMP24:
case R_ARM_THM_CALL:
case R_ARM_THM_JUMP19:
case R_ARM_THM_JUMP24:
case R_ARM_CALL:
return RAW_RELOC_NONE;
case R_ARM_ABS32:
return RAW_RELOC_32;
default:
grub_util_error (_("relocation 0x%x is not implemented yet"),
(unsigned int) ELF_R_TYPE (info));
break;
}
break;
default:
grub_util_error ("unknown machine type 0x%x", image_target->elf_target);
}
}
static void
finish_reloc_translation (struct translate_context *ctx,
struct grub_mkimage_layout *layout,
translate_relocation_raw (struct translate_context *ctx,
Elf_Addr addr,
Elf_Addr info,
const struct grub_install_image_target_desc *image_target)
{
enum raw_reloc_type class = classify_raw_reloc (info, image_target);
struct raw_reloc *rel;
if (class == RAW_RELOC_NONE)
return;
rel = xmalloc (sizeof (*rel));
rel->next = ctx->raw_relocs;
rel->type = class;
rel->offset = addr;
ctx->raw_relocs = rel;
}
static void
translate_relocation (struct translate_context *ctx,
Elf_Addr addr,
Elf_Addr info,
const struct grub_install_image_target_desc *image_target)
{
if (image_target->id == IMAGE_EFI)
translate_relocation_pe (ctx, addr, info, image_target);
else
translate_relocation_raw (ctx, addr, info, image_target);
}
static void
finish_reloc_translation_pe (struct translate_context *ctx, struct grub_mkimage_layout *layout,
const struct grub_install_image_target_desc *image_target)
{
ctx->current_address = add_fixup_entry (&ctx->lst, 0, 0, 1, ctx->current_address, image_target);
@ -1381,14 +1466,90 @@ finish_reloc_translation (struct translate_context *ctx,
}
layout->reloc_size = ctx->current_address;
if (image_target->elf_target == EM_ARM && layout->reloc_size > GRUB_KERNEL_ARM_STACK_SIZE)
grub_util_error ("Reloc section (%d) is bigger than stack size (%d). "
"This breaks assembly assumptions. Please increase stack size",
(int) layout->reloc_size,
(int) GRUB_KERNEL_ARM_STACK_SIZE);
}
/*
Layout:
<type 0 relocations>
<fffffffe>
<type 1 relocations>
<fffffffe>
...
<type n relocations>
<ffffffff>
each relocation starts with 32-bit offset. Rest depends on relocation.
mkimage stops when it sees first unknown type or end marker.
This allows images to be created with mismatched mkimage and
kernel as long as no relocations are present in kernel that mkimage
isn't aware of (in which case mkimage aborts).
This also allows simple assembly to do the relocs.
*/
#define RAW_SEPARATOR 0xfffffffe
#define RAW_END_MARKER 0xffffffff
static void
finish_reloc_translation_raw (struct translate_context *ctx, struct grub_mkimage_layout *layout,
const struct grub_install_image_target_desc *image_target)
{
size_t count = 0, sz;
enum raw_reloc_type highest = RAW_RELOC_NONE;
enum raw_reloc_type curtype;
struct raw_reloc *cur;
grub_uint32_t *p;
if (!ctx->raw_relocs)
{
layout->reloc_section = p = xmalloc (sizeof (grub_uint32_t));
p[0] = RAW_END_MARKER;
layout->reloc_size = sizeof (grub_uint32_t);
return;
}
for (cur = ctx->raw_relocs; cur; cur = cur->next)
{
count++;
if (cur->type > highest)
highest = cur->type;
}
/* highest separators, count relocations and one end marker. */
sz = (highest + count + 1) * sizeof (grub_uint32_t);
layout->reloc_section = p = xmalloc (sz);
for (curtype = 0; curtype <= highest; curtype++)
{
/* Support for special cases would go here. */
for (cur = ctx->raw_relocs; cur; cur = cur->next)
if (cur->type == curtype)
{
*p++ = cur->offset;
}
*p++ = RAW_SEPARATOR;
}
*--p = RAW_END_MARKER;
layout->reloc_size = sz;
}
static void
finish_reloc_translation (struct translate_context *ctx, struct grub_mkimage_layout *layout,
const struct grub_install_image_target_desc *image_target)
{
if (image_target->id == IMAGE_EFI)
finish_reloc_translation_pe (ctx, layout, image_target);
else
finish_reloc_translation_raw (ctx, layout, image_target);
}
static void
translate_reloc_jumpers (struct translate_context *ctx,
Elf_Addr jumpers, grub_size_t njumpers,
const struct grub_install_image_target_desc *image_target)
{
unsigned i;
assert (image_target->id == IMAGE_EFI);
for (i = 0; i < njumpers; i++)
ctx->current_address = add_fixup_entry (&ctx->lst,
GRUB_PE32_REL_BASED_DIR64,
@ -1403,14 +1564,13 @@ make_reloc_section (Elf_Ehdr *e, struct grub_mkimage_layout *layout,
Elf_Addr *section_addresses, Elf_Shdr *sections,
Elf_Half section_entsize, Elf_Half num_sections,
const char *strtab,
Elf_Addr jumpers, grub_size_t njumpers,
const struct grub_install_image_target_desc *image_target)
{
unsigned i;
Elf_Shdr *s;
struct translate_context ctx;
translate_reloc_start (&ctx);
translate_reloc_start (&ctx, image_target);
for (i = 0, s = sections; i < num_sections;
i++, s = (Elf_Shdr *) ((char *) s + section_entsize))
@ -1451,7 +1611,10 @@ make_reloc_section (Elf_Ehdr *e, struct grub_mkimage_layout *layout,
}
if (image_target->elf_target == EM_IA_64)
translate_reloc_jumpers (&ctx, jumpers, njumpers,
translate_reloc_jumpers (&ctx,
layout->ia64jmp_off
+ image_target->vaddr_offset,
2 * layout->ia64jmpnum + (layout->got_size / 8),
image_target);
finish_reloc_translation (&ctx, layout, image_target);
@ -1462,7 +1625,7 @@ make_reloc_section (Elf_Ehdr *e, struct grub_mkimage_layout *layout,
static int
SUFFIX (is_text_section) (Elf_Shdr *s, const struct grub_install_image_target_desc *image_target)
{
if (image_target->id != IMAGE_EFI
if (!is_relocatable (image_target)
&& grub_target_to_host32 (s->sh_type) != SHT_PROGBITS)
return 0;
return ((grub_target_to_host (s->sh_flags) & (SHF_EXECINSTR | SHF_ALLOC))
@ -1473,7 +1636,7 @@ SUFFIX (is_text_section) (Elf_Shdr *s, const struct grub_install_image_target_de
static int
SUFFIX (is_data_section) (Elf_Shdr *s, const struct grub_install_image_target_desc *image_target)
{
if (image_target->id != IMAGE_EFI
if (!is_relocatable (image_target)
&& grub_target_to_host32 (s->sh_type) != SHT_PROGBITS)
return 0;
return ((grub_target_to_host (s->sh_flags) & (SHF_EXECINSTR | SHF_ALLOC))
@ -1536,14 +1699,13 @@ SUFFIX (put_section) (Elf_Shdr *s, int i,
into .text and .data, respectively. Return the array of section
addresses. */
static Elf_Addr *
SUFFIX (locate_sections) (const char *kernel_path,
SUFFIX (locate_sections) (Elf_Ehdr *e, const char *kernel_path,
Elf_Shdr *sections, Elf_Half section_entsize,
Elf_Half num_sections, const char *strtab,
struct grub_mkimage_layout *layout,
const struct grub_install_image_target_desc *image_target)
{
int i;
Elf_Addr current_address;
Elf_Addr *section_addresses;
Elf_Shdr *s;
@ -1555,7 +1717,7 @@ SUFFIX (locate_sections) (const char *kernel_path,
section_addresses = xmalloc (sizeof (*section_addresses) * num_sections);
memset (section_addresses, 0, sizeof (*section_addresses) * num_sections);
current_address = 0;
layout->kernel_size = 0;
for (i = 0, s = sections;
i < num_sections;
@ -1571,8 +1733,8 @@ SUFFIX (locate_sections) (const char *kernel_path,
i++, s = (Elf_Shdr *) ((char *) s + section_entsize))
if (SUFFIX (is_text_section) (s, image_target))
{
current_address = SUFFIX (put_section) (s, i,
current_address,
layout->kernel_size = SUFFIX (put_section) (s, i,
layout->kernel_size,
section_addresses,
strtab,
image_target);
@ -1589,42 +1751,63 @@ SUFFIX (locate_sections) (const char *kernel_path,
}
}
current_address = ALIGN_UP (current_address + image_target->vaddr_offset,
layout->kernel_size = ALIGN_UP (layout->kernel_size + image_target->vaddr_offset,
image_target->section_align)
- image_target->vaddr_offset;
layout->exec_size = current_address;
layout->exec_size = layout->kernel_size;
/* .data */
for (i = 0, s = sections;
i < num_sections;
i++, s = (Elf_Shdr *) ((char *) s + section_entsize))
if (SUFFIX (is_data_section) (s, image_target))
current_address = SUFFIX (put_section) (s, i,
current_address,
layout->kernel_size = SUFFIX (put_section) (s, i,
layout->kernel_size,
section_addresses,
strtab,
image_target);
current_address = ALIGN_UP (current_address + image_target->vaddr_offset,
image_target->section_align) - image_target->vaddr_offset;
#ifdef MKIMAGE_ELF32
if (image_target->elf_target == EM_ARM)
{
grub_size_t tramp;
layout->kernel_size = ALIGN_UP (layout->kernel_size + image_target->vaddr_offset,
image_target->section_align) - image_target->vaddr_offset;
layout->bss_start = current_address;
layout->kernel_size = ALIGN_UP (layout->kernel_size, 16);
tramp = arm_get_trampoline_size (e, sections, section_entsize,
num_sections, image_target);
layout->tramp_off = layout->kernel_size;
layout->kernel_size += ALIGN_UP (tramp, 16);
}
#endif
layout->bss_start = layout->kernel_size;
layout->end = layout->kernel_size;
/* .bss */
for (i = 0, s = sections;
i < num_sections;
i++, s = (Elf_Shdr *) ((char *) s + section_entsize))
if (SUFFIX (is_bss_section) (s, image_target))
current_address = SUFFIX (put_section) (s, i,
current_address,
section_addresses,
strtab,
image_target);
layout->end = SUFFIX (put_section) (s, i,
layout->end,
section_addresses,
strtab,
image_target);
current_address = ALIGN_UP (current_address + image_target->vaddr_offset,
layout->end = ALIGN_UP (layout->end + image_target->vaddr_offset,
image_target->section_align) - image_target->vaddr_offset;
layout->end = current_address;
layout->kernel_size = current_address;
/* Explicitly initialize BSS
when producing PE32 to avoid a bug in EFI implementations.
Platforms other than EFI and U-boot shouldn't have .bss in
their binaries as we build with -Wl,-Ttext.
*/
if (image_target->id != IMAGE_UBOOT)
layout->kernel_size = layout->end;
return section_addresses;
}
@ -1674,7 +1857,7 @@ SUFFIX (grub_mkimage_load_image) (const char *kernel_path,
+ grub_host_to_target16 (e->e_shstrndx) * section_entsize);
strtab = (char *) e + grub_host_to_target_addr (s->sh_offset);
section_addresses = SUFFIX (locate_sections) (kernel_path,
section_addresses = SUFFIX (locate_sections) (e, kernel_path,
sections, section_entsize,
num_sections, strtab,
layout,
@ -1685,7 +1868,7 @@ SUFFIX (grub_mkimage_load_image) (const char *kernel_path,
for (i = 0; i < num_sections; i++)
section_vaddresses[i] = section_addresses[i] + image_target->vaddr_offset;
if (image_target->id != IMAGE_EFI)
if (!is_relocatable (image_target))
{
Elf_Addr current_address = layout->kernel_size;
@ -1706,7 +1889,7 @@ SUFFIX (grub_mkimage_load_image) (const char *kernel_path,
grub_util_info ("locating the section %s at 0x%"
GRUB_HOST_PRIxLONG_LONG,
name, (unsigned long long) current_address);
if (image_target->id != IMAGE_EFI)
if (!is_relocatable (image_target))
current_address = grub_host_to_target_addr (s->sh_addr)
- image_target->link_addr;
@ -1724,10 +1907,11 @@ SUFFIX (grub_mkimage_load_image) (const char *kernel_path,
if (image_target->id == IMAGE_SPARC64_AOUT
|| image_target->id == IMAGE_SPARC64_RAW
|| image_target->id == IMAGE_UBOOT
|| image_target->id == IMAGE_SPARC64_CDCORE)
layout->kernel_size = ALIGN_UP (layout->kernel_size, image_target->mod_align);
if (image_target->id == IMAGE_EFI)
if (is_relocatable (image_target))
{
symtab_section = NULL;
for (i = 0, s = sections;
@ -1740,22 +1924,6 @@ SUFFIX (grub_mkimage_load_image) (const char *kernel_path,
}
if (! symtab_section)
grub_util_error ("%s", _("no symbol table"));
#ifdef MKIMAGE_ELF32
if (image_target->elf_target == EM_ARM)
{
grub_size_t tramp;
layout->kernel_size = ALIGN_UP (layout->kernel_size, 16);
tramp = arm_get_trampoline_size (e, sections, section_entsize,
num_sections, image_target);
layout->tramp_off = layout->kernel_size;
layout->kernel_size += ALIGN_UP (tramp, 16);
}
#endif
#ifdef MKIMAGE_ELF64
if (image_target->elf_target == EM_IA_64)
{
@ -1770,14 +1938,13 @@ SUFFIX (grub_mkimage_load_image) (const char *kernel_path,
layout->ia64jmp_off = layout->kernel_size;
layout->ia64jmpnum = SUFFIX (count_funcs) (e, symtab_section,
image_target);
image_target);
layout->kernel_size += 16 * layout->ia64jmpnum;
layout->ia64_got_off = layout->kernel_size;
layout->kernel_size += ALIGN_UP (layout->got_size, 16);
}
#endif
}
else
{
@ -1788,7 +1955,7 @@ SUFFIX (grub_mkimage_load_image) (const char *kernel_path,
out_img = xmalloc (layout->kernel_size + total_module_size);
memset (out_img, 0, layout->kernel_size + total_module_size);
if (image_target->id == IMAGE_EFI)
if (is_relocatable (image_target))
{
layout->start_address = SUFFIX (relocate_symbols) (e, sections, symtab_section,
section_vaddresses, section_entsize,
@ -1796,6 +1963,8 @@ SUFFIX (grub_mkimage_load_image) (const char *kernel_path,
(char *) out_img + layout->ia64jmp_off,
layout->ia64jmp_off
+ image_target->vaddr_offset,
layout->bss_start,
layout->end,
image_target);
if (layout->start_address == (Elf_Addr) -1)
grub_util_error ("start symbol is not defined");
@ -1813,21 +1982,31 @@ SUFFIX (grub_mkimage_load_image) (const char *kernel_path,
make_reloc_section (e, layout,
section_vaddresses, sections,
section_entsize, num_sections,
strtab, layout->ia64jmp_off
+ image_target->vaddr_offset,
2 * layout->ia64jmpnum + (layout->got_size / 8),
strtab,
image_target);
if (image_target->id != IMAGE_EFI)
{
out_img = xrealloc (out_img, layout->kernel_size + total_module_size
+ ALIGN_UP (layout->reloc_size, image_target->mod_align));
memcpy (out_img + layout->kernel_size, layout->reloc_section, layout->reloc_size);
memset (out_img + layout->kernel_size + layout->reloc_size, 0,
total_module_size + ALIGN_UP (layout->reloc_size, image_target->mod_align) - layout->reloc_size);
layout->kernel_size += ALIGN_UP (layout->reloc_size, image_target->mod_align);
}
}
for (i = 0, s = sections;
i < num_sections;
i++, s = (Elf_Shdr *) ((char *) s + section_entsize))
if (SUFFIX (is_data_section) (s, image_target)
|| SUFFIX (is_bss_section) (s, image_target)
/* Explicitly initialize BSS
when producing PE32 to avoid a bug in EFI implementations.
Platforms other than EFI and U-boot shouldn't have .bss in
their binaries as we build with -Wl,-Ttext.
*/
|| (SUFFIX (is_bss_section) (s, image_target) && (image_target->id != IMAGE_UBOOT))
|| SUFFIX (is_text_section) (s, image_target))
{
/* Explicitly initialize BSS
when producing PE32 to avoid a bug in EFI implementations. */
if (grub_target_to_host32 (s->sh_type) == SHT_NOBITS)
memset (out_img + section_addresses[i], 0,
grub_host_to_target_addr (s->sh_size));