diff options
| author | Marek Vasut <[email protected]> | 2026-03-16 00:54:05 +0100 |
|---|---|---|
| committer | Tom Rini <[email protected]> | 2026-03-27 13:29:31 -0600 |
| commit | d9eee3d17882ec40f8ca5e231046bbf287ab4369 (patch) | |
| tree | fae19e970eea019143c8f152fc507c70601aa578 /arch | |
| parent | e20405860790d344035464e29e0eb237b42284ea (diff) | |
arm: relocate: Introduce data-only relocation mode
Introduce new mode of relocation which relocates only data, not code.
This is mainly meant to relocate data to read-write portion of the RAM,
while the code remains in read-only portion of the RAM from which it is
allowed to execute. This split configuration is present on various secure
cores.
The result of the relocation is U-Boot running at its original address,
data relocated to the end of DRAM, but with added read-write area offset.
The U-Boot binary area is not reserved from the end of the DRAM in this
relocation mode, because U-Boot itself is not relocated.
Signed-off-by: Marek Vasut <[email protected]>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/lib/crt0.S | 4 | ||||
| -rw-r--r-- | arch/arm/lib/relocate.S | 25 |
2 files changed, 29 insertions, 0 deletions
diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S index d10c129705d..f2c5aa37a8f 100644 --- a/arch/arm/lib/crt0.S +++ b/arch/arm/lib/crt0.S @@ -157,7 +157,11 @@ ENTRY(_main) orr lr, #1 /* As required by Thumb-only */ #endif ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */ +#if defined(CONFIG_SKIP_RELOCATE_CODE) + bl relocate_code +#else b relocate_code +#endif here: /* * now relocate vectors diff --git a/arch/arm/lib/relocate.S b/arch/arm/lib/relocate.S index 6ee58f4edfe..b6a648708f4 100644 --- a/arch/arm/lib/relocate.S +++ b/arch/arm/lib/relocate.S @@ -79,6 +79,15 @@ ENDPROC(relocate_vectors) ENTRY(relocate_code) relocate_base: adr r3, relocate_base + +#ifdef CONFIG_SKIP_RELOCATE_CODE + mov r4, #CONFIG_SKIP_RELOCATE_CODE_DATA_OFFSET + + ldr r1, _data_start_ofs + add r5, r1, r3 /* r5 <- Run &__data_start */ + ldr r1, _data_end_ofs + add r6, r1, r3 /* r6 <- Run &__data_end */ +#else ldr r1, _image_copy_start_ofs add r1, r3 /* r1 <- Run &__image_copy_start */ subs r4, r0, r1 /* r4 <- Run to copy offset */ @@ -90,6 +99,7 @@ copy_loop: stmia r0!, {r10-r11} /* copy to target address [r0] */ cmp r1, r2 /* until source end address [r2] */ blo copy_loop +#endif /* * fix .rel.dyn relocations @@ -107,6 +117,15 @@ fixloop: /* relative fix: increase location by offset */ add r0, r0, r4 ldr r1, [r0] + +#ifdef CONFIG_SKIP_RELOCATE_CODE + /* Test whether this is data, if not, do not relocate. */ + cmp r1, r5 + blt fixnext + cmp r1, r6 + bgt fixnext +#endif + add r1, r1, r4 str r1, [r0] fixnext: @@ -126,3 +145,9 @@ _rel_dyn_start_ofs: .word __rel_dyn_start - relocate_code _rel_dyn_end_ofs: .word __rel_dyn_end - relocate_code +#ifdef CONFIG_SKIP_RELOCATE_CODE +_data_start_ofs: + .word __data_start - relocate_code +_data_end_ofs: + .word __data_end - relocate_code +#endif |