[U-Boot] [RFC] [PATCH V2] arm: arm926ejs: use ELF relocations

[Heiko Schocher]

Hello Albert,

Heiko Schocher wrote:
> Albert Aribaud wrote:
>> HISTORY:
>>
>> V1	Initial patch
>> V2	Rebased on latest mainline master
>>
>> This patch is *not* a submission for master!
>>
>> It is a proof of concept of ELF relocations for ARM, hastily done
>> in a day's work time for people on the list to try and to comment.
>> All comments are welcome, as several suggestions have been made
>> today on the list that I did not have time to incorporate, such as
>> rewriting the elf table fixup code in C.
> 
> Following patch works on the tx25 with booting from nand:

Sorry, I was to fast, I had a problem with to big nand_spl code,
fixed this now, as I didn;t activate -pie flag for NAND_SPL code,
as this don;t need relocation.

Also I use "blo" instead "ble" in start.S

here now the v2 patch for the tx25 board:

diff --git a/arch/arm/config.mk b/arch/arm/config.mk
index e9e02da..19b8f02 100644
--- a/arch/arm/config.mk
+++ b/arch/arm/config.mk
@@ -72,4 +72,6 @@ PLATFORM_LIBS += $(OBJTREE)/arch/arm/lib/eabi_compat.o
 endif
 endif
 LDSCRIPT := $(SRCTREE)/$(CPUDIR)/u-boot.lds
-PLATFORM_LDFLAGS += -pie
\ No newline at end of file
+ifndef CONFIG_NAND_SPL
+PLATFORM_LDFLAGS += -pie
+endif
diff --git a/arch/arm/cpu/arm926ejs/start.S b/arch/arm/cpu/arm926ejs/start.S
index 5a7ae7e..68e597c 100644
--- a/arch/arm/cpu/arm926ejs/start.S
+++ b/arch/arm/cpu/arm926ejs/start.S
@@ -266,7 +266,7 @@ fixnext:
 	str	r1, [r0]
 	add	r2, r2, #8	/* each rel.dyn entry is 8 bytes */
 	cmp	r2, r3
-	ble	fixloop
+	blo	fixloop
 #endif
 #endif	/* #ifndef CONFIG_SKIP_RELOCATE_UBOOT */

@@ -295,10 +295,10 @@ clbss_l:str	r2, [r0]		/* clear loop...		    */
  */
 #ifdef CONFIG_NAND_SPL
 	ldr     r0, _nand_boot_ofs
-	adr	r1, _start
-	add	pc, r0, r1
-_nand_boot_ofs
-	: .word nand_boot - _start
+	mov	pc, r0
+
+_nand_boot_ofs:
+	.word nand_boot
 #else
 	ldr	r0, _board_init_r_ofs
 	adr	r1, _start
diff --git a/board/karo/tx25/config.mk b/board/karo/tx25/config.mk
index 51ca1ab..8be6466 100644
--- a/board/karo/tx25/config.mk
+++ b/board/karo/tx25/config.mk
@@ -1,5 +1,5 @@
 ifdef CONFIG_NAND_SPL
 TEXT_BASE = 0x810c0000
 else
-TEXT_BASE = 0x81fc0000
+TEXT_BASE = 0x81200000
 endif
diff --git a/include/configs/tx25.h b/include/configs/tx25.h
index c798570..2be3699 100644
--- a/include/configs/tx25.h
+++ b/include/configs/tx25.h
@@ -41,7 +41,7 @@
 #define CONFIG_SYS_NAND_U_BOOT_OFFS	0x800
 #define CONFIG_SYS_NAND_U_BOOT_SIZE	0x30000

-#define CONFIG_SYS_NAND_U_BOOT_DST      (0x81fc0000)
+#define CONFIG_SYS_NAND_U_BOOT_DST      (0x81200000)
 #define CONFIG_SYS_NAND_U_BOOT_START    CONFIG_SYS_NAND_U_BOOT_DST

 #define CONFIG_SYS_NAND_PAGE_SIZE	2048
@@ -178,6 +178,7 @@

 /* additions for new relocation code, must added to all boards */
 #undef CONFIG_SYS_ARM_WITHOUT_RELOC /* This board is tested with relocation support */
+#define CONFIG_RELOC_FIXUP_WORKS
 #define CONFIG_SYS_SDRAM_BASE		PHYS_SDRAM_1
 #define CONFIG_SYS_INIT_SP_ADDR		(CONFIG_SYS_SDRAM_BASE + 0x1000 - /* Fix this */ \
 					CONFIG_SYS_GBL_DATA_SIZE)
diff --git a/nand_spl/board/karo/tx25/u-boot.lds b/nand_spl/board/karo/tx25/u-boot.lds
index c572557..5f95c87 100644
--- a/nand_spl/board/karo/tx25/u-boot.lds
+++ b/nand_spl/board/karo/tx25/u-boot.lds
@@ -53,6 +53,11 @@ SECTIONS
 		*(.data.rel.ro)
 	}

+	. = ALIGN(4);
+	__rel_dyn_start = .;
+	__rel_dyn_end = .;
+	__dynsym_start = .;
+
 	__got_start = .;
 	. = ALIGN(4);
 	.got : { *(.got) }
@@ -67,4 +72,12 @@ SECTIONS
 	__bss_start = .;
 	.bss : { *(.bss) }
 	_end = .;
+	/DISCARD/ : { *(.bss*) }
+	/DISCARD/ : { *(.dynstr*) }
+	/DISCARD/ : { *(.dynsym*) }
+	/DISCARD/ : { *(.dynamic*) }
+	/DISCARD/ : { *(.hash*) }
+	/DISCARD/ : { *(.plt*) }
+	/DISCARD/ : { *(.interp*) }
+	/DISCARD/ : { *(.gnu*) }
 }
-- 
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