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Merge pull request #14 from devkitPro/dynamic-parsing

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Linkscript overhaul & .dynamic section parsing
This commit is contained in:
yellows8 2017-09-21 19:37:32 -04:00 committed by GitHub
commit 5ef41f9e07
7 changed files with 191 additions and 221 deletions
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160
buildscripts/lib/switch.ld
View File

@ -6,137 +6,157 @@ PHDRS
code PT_LOAD FLAGS(5) /* Read | Execute */;
rodata PT_LOAD FLAGS(4) /* Read */;
data PT_LOAD FLAGS(6) /* Read | Write */;
dyn PT_DYNAMIC;
}
SECTIONS
{
/* =========== CODE section =========== */
PROVIDE(__start__ = 0x0);
. = __start__;
.text ALIGN(0x1000) :
.crt0 :
{
KEEP (*(.crt0))
. = ALIGN(8);
} :code
.init :
{
/* .init */
KEEP( *(.crt0) )
KEEP( *(.init) )
. = ALIGN(4);
. = ALIGN(8);
} :code
/* .text */
*(.text)
*(.text.*)
*(.glue_7)
*(.glue_7t)
*(.stub)
*(.gnu.warning)
*(.gnu.linkonce.t*)
. = ALIGN(4);
.plt :
{
*(.plt)
*(.iplt)
. = ALIGN(8);
} :code
/* .fini */
.text :
{
*(.text.unlikely .text.*_unlikely .text.unlikely.*)
*(.text.exit .text.exit.*)
*(.text.startup .text.startup.*)
*(.text.hot .text.hot.*)
*(.text .stub .text.* .gnu.linkonce.t.*)
. = ALIGN(8);
} :code
.fini :
{
KEEP( *(.fini) )
. = ALIGN(4);
} : code
. = ALIGN(8);
} :code
/* =========== RODATA section =========== */
. = ALIGN(0x1000);
.rodata ALIGN(0x1000) :
.rodata :
{
*(.rodata)
*(.roda)
*(.rodata.*)
*all.rodata*(*)
*(.gnu.linkonce.r*)
SORT(CONSTRUCTORS)
. = ALIGN(4);
} : rodata
*(.rodata .rodata.* .gnu.linkonce.r.*)
. = ALIGN(8);
} :rodata
.ARM.extab : { *(.ARM.extab* .gnu.linkonce.armextab.*) } : rodata
__exidx_start = .;
ARM.exidx : { *(.ARM.exidx* .gnu.linkonce.armexidx.*) } : rodata
__exidx_end = .;
.eh_frame_hdr : { *(.eh_frame_hdr) *(.eh_frame_entry .eh_frame_entry.*) } :rodata
.eh_frame : ONLY_IF_RO { KEEP (*(.eh_frame)) *(.eh_frame.*) } :rodata
.gcc_except_table : ONLY_IF_RO { *(.gcc_except_table .gcc_except_table.*) } :rodata
.gnu_extab : ONLY_IF_RO { *(.gnu_extab*) } : rodata
.dynamic : { *(.dynamic) } :rodata :dyn
.interp : { *(.interp) } :rodata
.note.gnu.build-id : { *(.note.gnu.build-id) } :rodata
.hash : { *(.hash) } :rodata
.gnu.hash : { *(.gnu.hash) } :rodata
.gnu.version : { *(.gnu.version) } :rodata
.gnu.version_d : { *(.gnu.version_d) } :rodata
.gnu.version_r : { *(.gnu.version_r) } :rodata
.dynsym : { *(.dynsym) } :rodata
.dynstr : { *(.dynstr) } :rodata
.rela.dyn : { *(.rela.*) } :rodata
/* =========== DATA section =========== */
. = ALIGN(0x1000);
.data ALIGN(0x1000) :
{
*(.data)
*(.data.*)
*(.gnu.linkonce.d*)
CONSTRUCTORS
. = ALIGN(4);
__got_start__ = .;
*(.got)
__got_end__ = .;
} : data
.eh_frame : ONLY_IF_RW { KEEP (*(.eh_frame)) *(.eh_frame.*) } :data
.gcc_except_table : ONLY_IF_RW { *(.gcc_except_table .gcc_except_table.*) } :data
.gnu_extab : ONLY_IF_RW { *(.gnu_extab*) } : data
.exception_ranges : ONLY_IF_RW { *(.exception_ranges .exception_ranges*) } :data
.tdata ALIGN(4) :
.tdata ALIGN(8) :
{
__tdata_lma = .;
*(.tdata)
*(.tdata.*)
*(.gnu.linkonce.td.*)
. = ALIGN(4);
*(.tdata .tdata.* .gnu.linkonce.td.*)
. = ALIGN(8);
__tdata_lma_end = .;
} : data
} :data
.tbss ALIGN(4) :
.tbss ALIGN(8) :
{
*(.tbss)
*(.tbss.*)
*(.gnu.linkonce.tb.*)
*(.tcommon)
. = ALIGN(4);
} : data
*(.tbss .tbss.* .gnu.linkonce.tb.*) *(.tcommon)
. = ALIGN(8);
} :data
.preinit_array ALIGN(4) :
.preinit_array ALIGN(8) :
{
PROVIDE (__preinit_array_start = .);
KEEP (*(.preinit_array))
PROVIDE (__preinit_array_end = .);
} : data
} :data
.init_array ALIGN(4) :
.init_array ALIGN(8) :
{
PROVIDE (__init_array_start = .);
KEEP (*(SORT(.init_array.*)))
KEEP (*(.init_array))
PROVIDE (__init_array_end = .);
} : data
} :data
.fini_array ALIGN(4) :
.fini_array ALIGN(8) :
{
PROVIDE (__fini_array_start = .);
KEEP (*(.fini_array))
KEEP (*(SORT(.fini_array.*)))
PROVIDE (__fini_array_end = .);
} : data
} :data
.ctors ALIGN(4) :
.ctors ALIGN(8) :
{
KEEP (*crtbegin.o(.ctors)) /* MUST be first -- GCC requires it */
KEEP (*(EXCLUDE_FILE (*crtend.o) .ctors))
KEEP (*(SORT(.ctors.*)))
KEEP (*(.ctors))
} : data
} :data
.dtors ALIGN(4) :
.dtors ALIGN(8) :
{
KEEP (*crtbegin.o(.dtors))
KEEP (*(EXCLUDE_FILE (*crtend.o) .dtors))
KEEP (*(SORT(.dtors.*)))
KEEP (*(.dtors))
} : data
} :data
__got_start__ = .;
.got : { *(.got) *(.igot) } :data
.got.plt : { *(.got.plt) *(.igot.plt) } :data
__got_end__ = .;
.data ALIGN(8) :
{
*(.data .data.* .gnu.linkonce.d.*)
SORT(CONSTRUCTORS)
} :data
__bss_start__ = .;
.bss ALIGN(4) :
.bss ALIGN(8) :
{
*(.dynbss)
*(.bss)
*(.bss.*)
*(.gnu.linkonce.b*)
*(.bss .bss.* .gnu.linkonce.b.*)
*(COMMON)
. = ALIGN(4);
. = ALIGN(8);
/* Reserve space for the TLS segment of the main thread */
__tls_start = .;

2
buildscripts/lib/switch.specs
View File

@ -1,7 +1,7 @@
%rename link old_link
*link:
%(old_link) -T switch.ld%s -d --gc-sections
%(old_link) -T switch.ld%s -pie --gc-sections -z text
*startfile:
switch_crt0%O%s crti%O%s crtbegin%O%s

52
crt0/switch_crt0.s
View File

@ -3,55 +3,39 @@
_start:
bl startup
.word 0x454d4f48
.word 0x57455242
.ascii "HOMEBREW"
startup:
// get aslr base
sub x28, x30, #4
// clear .bss
ldr x0, =__bss_start__
ldr x1, =__bss_end__
adrp x0, __bss_start__
adrp x1, __bss_end__
add x0, x0, #:lo12:__bss_start__
add x1, x1, #:lo12:__bss_end__
sub x1, x1, x0 // calculate size
add x1, x1, #7 // round up to 8
bic x1, x1, #7
mov x2, #0
add x0, x0, x28 // relocate ptr
bss_loop:
str x2, [x0], #8
str xzr, [x0], #8
subs x1, x1, #8
bne bss_loop
// relocate .got
ldr x0, =__got_start__
ldr x1, =__got_end__
sub x1, x1, x0 // calculate size
add x1, x1, #7 // round up to 8
bic x1, x1, #7
add x0, x0, x28 // relocate ptr
got_loop:
ldr x2, [x0]
add x2, x2, x28
str x2, [x0], #8
subs x1, x1, #8
bne got_loop
// process .dynamic section
mov x0, x28
ldr x3, =initSystem
add x3, x3, x28
blr x3
adrp x1, _DYNAMIC
add x1, x1, #:lo12:_DYNAMIC
bl __nx_dynamic
// initialize system
mov x0, x28
bl __nx_init
// call entrypoint
mov x0, #0 // argc
mov x1, #0 // argv
ldr x3, =main
add x3, x3, x28
ldr x2, =__nx_exit
add x2, x2, x28
mov x30, x2
br x3
adrp x30, __nx_exit
add x30, x30, #:lo12:__nx_exit
b main

4
nx/Makefile
View File

@ -32,9 +32,9 @@ INCLUDES := include
#---------------------------------------------------------------------------------
# options for code generation
#---------------------------------------------------------------------------------
ARCH := -march=armv8-a
ARCH := -march=armv8-a -fPIC
CFLAGS := -g -Wall -Werror -fPIC \
CFLAGS := -g -Wall -Werror \
-ffunction-sections \
-fdata-sections \
$(ARCH) \

37
nx/source/system/dynamic.c Normal file
View File

@ -0,0 +1,37 @@
#include <switch/types.h>
#include <elf.h>
void __nx_dynamic(uintptr_t base, const Elf64_Dyn* dyn)
{
const Elf64_Rela* rela = NULL;
u64 relasz = 0;
for (; dyn->d_tag != DT_NULL; dyn++)
{
switch (dyn->d_tag)
{
case DT_RELA:
rela = (const Elf64_Rela*)(base + dyn->d_un.d_ptr);
break;
case DT_RELASZ:
relasz = dyn->d_un.d_val / sizeof(Elf64_Rela);
break;
}
}
if (rela == NULL)
for (;;); // Panic
for (; relasz--; rela++)
{
switch (ELF64_R_TYPE(rela->r_info))
{
case R_AARCH64_RELATIVE:
{
u64* ptr = (u64*)(base + rela->r_offset);
*ptr = base + rela->r_addend;
break;
}
}
}
}

92
nx/source/system/sysinit.s
View File

@ -1,99 +1,19 @@
.text
.global initSystem
.type initSystem, %function
.global __nx_init
.type __nx_init, %function
initSystem:
__nx_init:
stp x29, x30, [sp, #-16]!
adr x1, __nx_binarybase
str x0, [x1]
bl __libnx_init
bl __appInit
bl __nx_libc_init_array
bl __libc_init_array
ldp x29, x30, [sp], #16
ret
.global __nx_exit
.type __nx_exit, %function
.type __nx_exit, %function
__nx_exit:
bl __nx_libc_fini_array
bl __libc_fini_array
bl __appExit
b __libnx_exit
__nx_libc_init_array:
stp x29, x30, [sp, #-16]!
stp x21, x22, [sp, #-16]!
stp x19, x20, [sp, #-16]!
adr x3, __nx_binarybase
ldr x20, [x3]
ldr x0, =__preinit_array_start
ldr x1, =__preinit_array_end
sub x1, x1, x0
add x21, x0, x20
lsr x19, x1, #3
cbz x19, __nx_libc_init_array_end0
__nx_libc_init_array_lp0:
ldr x3, [x21], #8
sub x19, x19, #1
add x3, x3, x20
blr x3
cbnz x19, __nx_libc_init_array_lp0
__nx_libc_init_array_end0:
bl _init
ldr x0, =__init_array_start
ldr x1, =__init_array_end
sub x1, x1, x0
add x21, x0, x20
lsr x19, x1, #3
cbz x19, __nx_libc_init_array_end1
__nx_libc_init_array_lp1:
ldr x3, [x21], #8
sub x19, x19, #1
add x3, x3, x20
blr x3
cbnz x19, __nx_libc_init_array_lp1
__nx_libc_init_array_end1:
ldp x19, x20, [sp], #16
ldp x21, x22, [sp], #16
ldp x29, x30, [sp], #16
ret
__nx_libc_fini_array:
stp x29, x30, [sp, #-16]!
stp x21, x22, [sp, #-16]!
stp x19, x20, [sp, #-16]!
adr x3, __nx_binarybase
ldr x20, [x3]
ldr x0, =__fini_array_start
ldr x1, =__fini_array_end
sub x1, x1, x0
add x21, x0, x20
lsr x19, x1, #3
cbz x19, __nx_libc_fini_array_end
__nx_libc_fini_array_lp:
sub x19, x19, #1
ldr x3, [x21, x19, lsl #3]
add x3, x3, x20
blr x3
cbnz x19, __nx_libc_fini_array_lp
__nx_libc_fini_array_end:
ldp x19, x20, [sp], #16
ldp x21, x22, [sp], #16
ldp x29, x30, [sp], #16
ret
.data
__nx_binarybase:
.dword 0

65
tools/elf2nso.c
View File

@ -62,8 +62,8 @@ uint8_t* ReadEntireFile(const char* fn, size_t* len_out) {
int main(int argc, char* argv[]) {
if (argc != 3) {
printf("%s <elf-file> <nso-file>\n", argv[0]);
return 1;
fprintf(stderr, "%s <elf-file> <nso-file>\n", argv[0]);
return EXIT_FAILURE;
}
NsoHeader nso_hdr;
@ -72,48 +72,57 @@ int main(int argc, char* argv[]) {
nso_hdr.Unk3 = 0x3f;
if (sizeof(NsoHeader) != 0x100) {
printf("Bad compile environment!\n");
return 1;
fprintf(stderr, "Bad compile environment!\n");
return EXIT_FAILURE;
}
size_t elf_len;
uint8_t* elf = ReadEntireFile(argv[1], &elf_len);
if (elf == NULL) {
printf("Failed to open input!\n");
return 1;
fprintf(stderr, "Failed to open input!\n");
return EXIT_FAILURE;
}
if (elf_len < sizeof(Elf64_Ehdr)) {
printf("Input file doesn't fit ELF header!\n");
return 1;
fprintf(stderr, "Input file doesn't fit ELF header!\n");
return EXIT_FAILURE;
}
Elf64_Ehdr* hdr = (Elf64_Ehdr*) elf;
if (hdr->e_machine != EM_AARCH64) {
printf("Invalid ELF: expected AArch64!\n");
return 1;
fprintf(stderr, "Invalid ELF: expected AArch64!\n");
return EXIT_FAILURE;
}
Elf64_Off ph_end = hdr->e_phoff + 3 * sizeof(Elf64_Phdr);
Elf64_Off ph_end = hdr->e_phoff + hdr->e_phnum * sizeof(Elf64_Phdr);
if (ph_end < hdr->e_phoff || ph_end > elf_len) {
printf("Invalid ELF: phdrs outside file!\n");
return 1;
fprintf(stderr, "Invalid ELF: phdrs outside file!\n");
return EXIT_FAILURE;
}
if (hdr->e_phnum != 3) {
printf("Invalid ELF: expected 3 phdrs!\n");
return 1;
}
Elf64_Phdr* phdr = (Elf64_Phdr*) &elf[hdr->e_phoff];
size_t i;
Elf64_Phdr* phdrs = (Elf64_Phdr*) &elf[hdr->e_phoff];
size_t i, j = 0;
size_t file_off = sizeof(NsoHeader);
uint8_t* comp_buf[3];
int comp_sz[3];
for (i=0; i<3; i++, phdr++) {
for (i=0; i<3; i++) {
Elf64_Phdr* phdr = NULL;
while (j < hdr->e_phnum) {
Elf64_Phdr* cur = &phdrs[j++];
if (cur->p_type == PT_LOAD) {
phdr = cur;
break;
}
}
if (phdr == NULL) {
fprintf(stderr, "Invalid ELF: expected 3 loadable phdrs!\n");
return EXIT_FAILURE;
}
nso_hdr.Segments[i].FileOff = file_off;
nso_hdr.Segments[i].DstOff = phdr->p_vaddr;
nso_hdr.Segments[i].DecompSz = phdr->p_filesz;
@ -133,16 +142,16 @@ int main(int argc, char* argv[]) {
comp_buf[i] = malloc(comp_max);
if (comp_buf[i] == NULL) {
printf("Compressing: Out of memory!\n");
return 1;
fprintf(stderr, "Compressing: Out of memory!\n");
return EXIT_FAILURE;
}
// TODO check p_offset
comp_sz[i] = LZ4_compress_default(&elf[phdr->p_offset], comp_buf[i], phdr->p_filesz, comp_max);
if (comp_sz[i] < 0) {
printf("Failed to compress!\n");
return 1;
fprintf(stderr, "Failed to compress!\n");
return EXIT_FAILURE;
}
nso_hdr.CompSz[i] = comp_sz[i];
@ -152,8 +161,8 @@ int main(int argc, char* argv[]) {
FILE* out = fopen(argv[2], "wb");
if (out == NULL) {
printf("Failed to open output file!\n");
return 1;
fprintf(stderr, "Failed to open output file!\n");
return EXIT_FAILURE;
}
// TODO check retvals
@ -162,5 +171,5 @@ int main(int argc, char* argv[]) {
for (i=0; i<3; i++)
fwrite(comp_buf[i], comp_sz[i], 1, out);
return 0;
return EXIT_SUCCESS;
}