arm64: Add support for larger PIE U-Boot

Linking a U-Boot larger than 1MB fails with PIE enabled:
u-boot/arch/arm/cpu/armv8/start.S:71:(.text+0x3c): relocation
truncated to fit: R_AARCH64_ADR_PREL_LO21 against symbol `__rel_dyn_end'
defined in .bss_start section in u-boot.

This extends the supported range by using adrp & add to load symbols
early while starting up.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

diff --git a/arch/arm/cpu/armv8/start.S b/arch/arm/cpu/armv8/start.S
index 85baebc5f78ea8438d125e3b5f45dba321f11a3c..e5c2856cf579abfd8953e0df48d36a542d147807 100644 (file)
--- a/arch/arm/cpu/armv8/start.S
+++ b/arch/arm/cpu/armv8/start.S
@@ -84,8 +84,10 @@ pie_fixup:
        adr     x0, _start              /* x0 <- Runtime value of _start */
        ldr     x1, _TEXT_BASE          /* x1 <- Linked value of _start */
        sub     x9, x0, x1              /* x9 <- Run-vs-link offset */
-       adr     x2, __rel_dyn_start     /* x2 <- Runtime &__rel_dyn_start */
-       adr     x3, __rel_dyn_end       /* x3 <- Runtime &__rel_dyn_end */
+       adrp    x2, __rel_dyn_start     /* x2 <- Runtime &__rel_dyn_start */
+       add     x2, x2, #:lo12:__rel_dyn_start
+       adrp    x3, __rel_dyn_end       /* x3 <- Runtime &__rel_dyn_end */
+       add     x3, x3, #:lo12:__rel_dyn_end
 pie_fix_loop:
        ldp     x0, x1, [x2], #16       /* (x0, x1) <- (Link location, fixup) */
        ldr     x4, [x2], #8            /* x4 <- addend */

diff --git a/arch/arm/lib/crt0_64.S b/arch/arm/lib/crt0_64.S
index 04afa518acf011b58ae28664e03480b31d6a00c1..9d2319c0e87cbf00f6dd2381e219b8d1bec9c107 100644 (file)
--- a/arch/arm/lib/crt0_64.S
+++ b/arch/arm/lib/crt0_64.S
@@ -73,7 +73,12 @@ ENTRY(_main)
 #elif defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_STACK)
        ldr     x0, =(CONFIG_SPL_STACK)
 #elif defined(CONFIG_INIT_SP_RELATIVE)
+#if CONFIG_POSITION_INDEPENDENT
+       adrp    x0, __bss_start     /* x0 <- Runtime &__bss_start */
+       add     x0, x0, #:lo12:__bss_start
+#else
        adr     x0, __bss_start
+#endif
        add     x0, x0, #CONFIG_SYS_INIT_SP_BSS_OFFSET
 #else
        ldr     x0, =(CONFIG_SYS_INIT_SP_ADDR)
@@ -102,7 +107,8 @@ ENTRY(_main)
        adr     lr, relocation_return
 #if CONFIG_POSITION_INDEPENDENT
        /* Add in link-vs-runtime offset */
-       adr     x0, _start              /* x0 <- Runtime value of _start */
+       adrp    x0, _start              /* x0 <- Runtime value of _start */
+       add     x0, x0, #:lo12:_start
        ldr     x9, _TEXT_BASE          /* x9 <- Linked value of _start */
        sub     x9, x9, x0              /* x9 <- Run-vs-link offset */
        add     lr, lr, x9