[U-Boot] [PATCH v2 3/3] arm: add spl relocation support for arm

[Andy Yan]

Some times we want to relocate spl code to dram after dram
initialization or relocate spl code to a high memory to avoid
code overid.

For example on Rockchip armv8 platform, we run with boot flow
TPL->SPL->ATF->U-Boot.
TPL run in sram and is responsible for dram initialization.
SPL run from the start address of dram and is responsible for
loading ATF and U-Boot.

The case here is that the ATF load address is from 64KB of dram,
which overlaps with spl code itself.

So we want to relocate spl itself to high memory to aovid this.

Signed-off-by: Andy Yan <andy.yan at rock-chips.com>
---

Changes in v2:
- Add more detial commit message

 arch/arm/config.mk                |  6 ++++++
 arch/arm/cpu/armv8/start.S        |  4 ++++
 arch/arm/cpu/armv8/u-boot-spl.lds | 17 +++++++++++++++++
 arch/arm/lib/Makefile             |  2 +-
 arch/arm/lib/crt0_64.S            |  3 ++-
 5 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/arch/arm/config.mk b/arch/arm/config.mk
index f25603109e..7f6ad89601 100644
--- a/arch/arm/config.mk
+++ b/arch/arm/config.mk
@@ -102,6 +102,12 @@ endif
 # needed for relocation
 LDFLAGS_u-boot += -pie
 
+ifndef CONFIG_SPL_SKIP_RELOCATE
+LDFLAGS_u-boot-spl = -pie
+else
+SPL_LDFLAGS_u-boot-spl =
+endif
+
 #
 # FIXME: binutils versions < 2.22 have a bug in the assembler where
 # branches to weak symbols can be incorrectly optimized in thumb mode
diff --git a/arch/arm/cpu/armv8/start.S b/arch/arm/cpu/armv8/start.S
index fe52166e28..a7dad3cd69 100644
--- a/arch/arm/cpu/armv8/start.S
+++ b/arch/arm/cpu/armv8/start.S
@@ -35,7 +35,11 @@ _start:
 
 .globl	_TEXT_BASE
 _TEXT_BASE:
+#if defined(CONFIG_SPL_BUILD)
+	.quad   CONFIG_SPL_TEXT_BASE
+#else
 	.quad	CONFIG_SYS_TEXT_BASE
+#endif
 
 /*
  * These are defined in the linker script.
diff --git a/arch/arm/cpu/armv8/u-boot-spl.lds b/arch/arm/cpu/armv8/u-boot-spl.lds
index ccbf359bd1..64102afc8b 100644
--- a/arch/arm/cpu/armv8/u-boot-spl.lds
+++ b/arch/arm/cpu/armv8/u-boot-spl.lds
@@ -53,6 +53,23 @@ SECTIONS
 		*(.__end)
 	} >.sram
 
+#ifndef CONFIG_SPL_SKIP_RELOCATE
+	. = ALIGN(8);
+
+	.rel_dyn_start :
+	{
+		*(.__rel_dyn_start)
+	} >.sram
+
+	.rela.dyn : {
+		*(.rela*)
+	} >.sram
+
+	.rel_dyn_end :
+	{
+		*(.__rel_dyn_end)
+	} >.sram
+#endif
 	_image_binary_end = .;
 
 	.bss_start (NOLOAD) : {
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 48ee6c3c60..f27b3fb79f 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -21,7 +21,7 @@ else
 obj-y   += setjmp.o
 endif
 
-ifndef CONFIG_SPL_BUILD
+ifndef CONFIG_TPL_BUILD
 ifdef CONFIG_ARM64
 obj-y	+= relocate_64.o
 else
diff --git a/arch/arm/lib/crt0_64.S b/arch/arm/lib/crt0_64.S
index d6b632aa87..e5605fe325 100644
--- a/arch/arm/lib/crt0_64.S
+++ b/arch/arm/lib/crt0_64.S
@@ -89,7 +89,8 @@ ENTRY(_main)
 	mov	x0, #0
 	bl	board_init_f
 
-#if !defined(CONFIG_SPL_BUILD)
+#if (defined(CONFIG_SPL_BUILD) && !defined(CONFIG_TPL_BUILD) && !defined(CONFIG_SPL_SKIP_RELOCATE)) || \
+	!defined(CONFIG_SPL_BUILD)
 /*
  * Set up intermediate environment (new sp and gd) and call
  * relocate_code(addr_moni). Trick here is that we'll return
-- 
2.17.1