@ -1,5 +1,5 @@
/ *
* Copyright ( c ) 2016 - 2020 , ARM Limited and Contributors. All rights reserved.
* Copyright ( c ) 2016 - 2021 , ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
* /
@ -7,6 +7,8 @@
# include < arch.h >
# include < asm_macros.S >
# include < assert_macros.S >
# include < common / bl_common.h >
# include < lib / xlat_tables / xlat_tables_defs.h >
.globl smc
.globl zeromem
@ -14,6 +16,9 @@
.globl memcpy4
.globl disable_mmu_icache_secure
.globl disable_mmu_secure
.globl fixup_gdt_reloc
# define PAGE_START_MASK ~ ( PAGE_SIZE_MASK )
func smc
/ *
@ -187,3 +192,124 @@ func disable_mmu_icache_secure
ldr r1 , = ( SCTLR_M_BIT | SCTLR_C_BIT | SCTLR_I_BIT )
b do_disable_mmu
endfunc disable_mmu_icache_secure
/ * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
* Helper to fixup Global Descriptor table ( GDT ) and dynamic relocations
* ( .rel.dyn ) at runtime.
*
* This function is meant to be used when the firmware is compiled with - fpie
* and linked with - pie options. We rely on the linker script exporting
* appropriate markers for start and end of the section. For GOT , we
* expect __GOT_START__ and __GOT_END__. Similarly for .rela.dyn , we expect
* __RELA_START__ and __RELA_END__.
*
* The function takes the limits of the memory to apply fixups to as
* arguments ( which is usually the limits of the relocable BL image ).
* r0 - the start of the fixup region
* r1 - the limit of the fixup region
* These addresses have to be 4 KB page aligned.
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
* /
/ * Relocation codes * /
# define R_ARM_RELATIVE 23
func fixup_gdt_reloc
mov r6 , r0
mov r7 , r1
# if ENABLE_ASSERTIONS
/ * Test if the limits are 4 K aligned * /
orr r0 , r0 , r1
mov r1 , # ( PAGE_SIZE_MASK )
tst r0 , r1
ASM_ASSERT ( eq )
# endif
/ *
* Calculate the offset based on return address in lr.
* Assume that this function is called within a page at the start of
* fixup region.
* /
ldr r1 , = PAGE_START_MASK
and r2 , lr , r1
subs r0 , r2 , r6 / * Diff ( S ) = Current Address - Compiled Address * /
beq 3 f / * Diff ( S ) = 0 . No relocation needed * /
ldr r1 , = __GOT_START__
add r1 , r1 , r0
ldr r2 , = __GOT_END__
add r2 , r2 , r0
/ *
* GOT is an array of 32 _bit addresses which must be fixed up as
* new_addr = old_addr + Diff ( S ).
* The new_addr is the address currently the binary is executing from
* and old_addr is the address at compile time.
* /
1 : ldr r3 , [ r1 ]
/ * Skip adding offset if address is < lower limit * /
cmp r3 , r6
blo 2 f
/ * Skip adding offset if address is > upper limit * /
cmp r3 , r7
bhi 2 f
add r3 , r3 , r0
str r3 , [ r1 ]
2 : add r1 , r1 , # 4
cmp r1 , r2
blo 1 b
/ * Starting dynamic relocations. Use ldr to get RELA_START and END * /
3 : ldr r1 , = __RELA_START__
add r1 , r1 , r0
ldr r2 , = __RELA_END__
add r2 , r2 , r0
/ *
* According to ELF-32 specification , the RELA data structure is as
* follows:
* typedef struct {
* Elf32_Addr r_offset ;
* Elf32_Xword r_info ;
* } Elf32_Rela ;
*
* r_offset is address of reference
* r_info is symbol index and type of relocation ( in this case
* code 23 which corresponds to R_ARM_RELATIVE ).
*
* Size of Elf32_Rela structure is 8 bytes.
* /
/ * Skip R_ARM_NONE entry with code 0 * /
1 : ldr r3 , [ r1 , # 4 ]
ands r3 , r3 , # 0xff
beq 2 f
# if ENABLE_ASSERTIONS
/ * Assert that the relocation type is R_ARM_RELATIVE * /
cmp r3 , # R_ARM_RELATIVE
ASM_ASSERT ( eq )
# endif
ldr r3 , [ r1 ] / * r_offset * /
add r3 , r0 , r3 / * Diff ( S ) + r_offset * /
ldr r4 , [ r3 ]
/ * Skip adding offset if address is < lower limit * /
cmp r4 , r6
blo 2 f
/ * Skip adding offset if address is > = upper limit * /
cmp r4 , r7
bhs 2 f
add r4 , r0 , r4
str r4 , [ r3 ]
2 : add r1 , r1 , # 8
cmp r1 , r2
blo 1 b
bx lr
endfunc fixup_gdt_reloc
Manish Pandey
4 years ago
TrustedFirmware Code Review