The code resulting from building the barebox ARM64 assembly contains relocations, which could've been position-independent just as well. Let's make them truly position independent by turning: ldr x0, =label into adr_l x0, label adr_l is position independent by virtue of being implemented using adrp, so it's usuable as-is before relocation and requires no manual addition of get_runtime_offset(). With these changes, only relocation necessary for the ARM64 generic DT 2nd stage is the one needed for get_runtime_offset() to find out whether barebox has been relocated. This is one step towards supporting mapping barebox PBL text section W^X, which precludes relocation entries emitted for code. With this change applied, there is still a data relocation entry in assembly code for get_runtime_offset(), but that doesn't bother us because it's in the data section. Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> --- arch/arm/cpu/setupc_64.S | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) diff --git a/arch/arm/cpu/setupc_64.S b/arch/arm/cpu/setupc_64.S index f38f893be90b..2138c2a600fa 100644 --- a/arch/arm/cpu/setupc_64.S +++ b/arch/arm/cpu/setupc_64.S @@ -1,6 +1,7 @@ /* SPDX-License-Identifier: GPL-2.0-only */ #include <linux/linkage.h> +#include <asm/assembler.h> #include <asm/sections.h> .section .text.setupc @@ -10,9 +11,9 @@ */ ENTRY(setup_c) mov x15, x30 - ldr x0, =__bss_start + adr_l x0, __bss_start mov x1, #0 - ldr x2, =__bss_stop + adr_l x2, __bss_stop sub x2, x2, x0 bl __memset /* clear bss */ mov x30, x15 @@ -29,12 +30,12 @@ ENDPROC(setup_c) /* x0: target address */ #ifdef __PBL__ ENTRY(relocate_to_adr_full) - ldr x2, =__image_end + adr_l x2, __image_end b 1f #endif ENTRY(relocate_to_adr) - ldr x2, =__bss_start + adr_l x2, __bss_start b 1f 1: @@ -45,18 +46,13 @@ ENTRY(relocate_to_adr) mov x21, x0 - bl get_runtime_offset - mov x5, x0 - - ldr x0, =_text - mov x20, x0 - - add x1, x0, x5 /* x1: from address */ + adr_l x1, _text + mov x20, x1 cmp x1, x21 /* already at correct address? */ beq 1f /* yes, skip copy to new address */ - sub x2, x2, x0 /* x2: size */ + sub x2, x2, x1 /* x2: size */ mov x0, x21 /* x0: target */ /* adjust return address */ @@ -70,7 +66,7 @@ ENTRY(relocate_to_adr) mov x0,#0 ic ivau, x0 /* flush icache */ - ldr x0,=1f + adr_l x0, 1f sub x0, x0, x20 add x0, x0, x21 br x0 /* jump to relocated address */ -- 2.39.2
