arm: implement ELF relocations

ELF relocation tables generated with linker option -pie can
be used to fixup code and data in a single loop at relocation,
removing the need for manual fixups anywhere else in the code.

Signed-off-by: Albert Aribaud <albert.aribaud@free.fr>

7 files changed, 156 insertions, 290 deletions

diff --git a/arch/arm/config.mk b/arch/arm/config.mk
index 6923f6d..0be47d3 100644
--- a/arch/arm/config.mk
+++ b/arch/arm/config.mk
@@ -33,11 +33,6 @@ STANDALONE_LOAD_ADDR = 0xc100000
 endif
 endif
 
-ifndef CONFIG_SYS_ARM_WITHOUT_RELOC
-# needed for relocation
-PLATFORM_RELFLAGS += -fPIC
-endif
-
 ifdef CONFIG_SYS_ARM_WITHOUT_RELOC
 PLATFORM_CPPFLAGS += -DCONFIG_SYS_ARM_WITHOUT_RELOC
 endif
@@ -72,3 +67,8 @@ PLATFORM_LIBS += $(OBJTREE)/arch/arm/lib/eabi_compat.o
 endif
 endif
 LDSCRIPT := $(SRCTREE)/$(CPUDIR)/u-boot.lds
+
+ifndef CONFIG_SYS_ARM_WITHOUT_RELOC
+# needed for relocation
+PLATFORM_LDFLAGS += -pie
+endif
diff --git a/arch/arm/cpu/arm926ejs/start.S b/arch/arm/cpu/arm926ejs/start.S
index a960689..49ca839 100644
--- a/arch/arm/cpu/arm926ejs/start.S
+++ b/arch/arm/cpu/arm926ejs/start.S
@@ -10,6 +10,7 @@
  *  Copyright (c) 2002	Gary Jennejohn <garyj@denx.de>
  *  Copyright (c) 2003	Richard Woodruff <r-woodruff2@ti.com>
  *  Copyright (c) 2003	Kshitij <kshitij@ti.com>
+ *  Copyright (c) 2010	Albert Aribaud <albert.aribaud@free.fr>
  *
  * See file CREDITS for list of people who contributed to this
  * project.
@@ -118,22 +119,19 @@ _fiq:
 _TEXT_BASE:
 	.word	TEXT_BASE
 
-#if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
-.globl _armboot_start
-_armboot_start:
-	.word _start
-#endif
-
 /*
  * These are defined in the board-specific linker script.
+ * Subtracting _start from them lets the linker put their
+ * relative position in the executable instead of leaving
+ * them null.
  */
-.globl _bss_start
-_bss_start:
-	.word __bss_start
+.globl _bss_start_ofs
+_bss_start_ofs:
+	.word __bss_start - _start
 
-.globl _bss_end
-_bss_end:
-	.word _end
+.globl _bss_end_ofs
+_bss_end_ofs:
+	.word _end - _start
 
 #ifdef CONFIG_USE_IRQ
 /* IRQ stack memory (calculated at run-time) */
@@ -153,30 +151,6 @@ FIQ_STACK_START:
 IRQ_STACK_START_IN:
 	.word	0x0badc0de
 
-.globl _datarel_start
-_datarel_start:
-	.word __datarel_start
-
-.globl _datarelrolocal_start
-_datarelrolocal_start:
-	.word __datarelrolocal_start
-
-.globl _datarellocal_start
-_datarellocal_start:
-	.word __datarellocal_start
-
-.globl _datarelro_start
-_datarelro_start:
-	.word __datarelro_start
-
-.globl _got_start
-_got_start:
-	.word __got_start
-
-.globl _got_end
-_got_end:
-	.word __got_end
-
 /*
  * the actual reset code
  */
@@ -226,9 +200,8 @@ stack_setup:
 
 	adr	r0, _start
 	ldr	r2, _TEXT_BASE
-	ldr	r3, _bss_start
-	sub	r2, r3, r2		/* r2 <- size of armboot	    */
-	add	r2, r0, r2		/* r2 <- source end address	    */
+	ldr	r3, _bss_start_ofs
+	add	r2, r0, r3		/* r2 <- source end address	    */
 	cmp	r0, r6
 	beq	clear_bss
 
@@ -240,36 +213,54 @@ copy_loop:
 	blo	copy_loop
 
 #ifndef CONFIG_PRELOADER
-	/* fix got entries */
-	ldr	r1, _TEXT_BASE		/* Text base */
-	mov	r0, r7			/* reloc addr */
-	ldr	r2, _got_start		/* addr in Flash */
-	ldr	r3, _got_end		/* addr in Flash */
-	sub	r3, r3, r1
-	add	r3, r3, r0
-	sub	r2, r2, r1
-	add	r2, r2, r0
-
+	/*
+	 * fix .rel.dyn relocations
+	 */
+	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
+	sub	r9, r7, r0		/* r9 <- relocation offset */
+	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
+	add	r10, r10, r0		/* r10 <- sym table in FLASH */
+	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
+	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
+	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
+	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
 fixloop:
-	ldr	r4, [r2]
-	sub	r4, r4, r1
-	add	r4, r4, r0
-	str	r4, [r2]
-	add	r2, r2, #4
+	ldr	r0, [r2]	/* r0 <- location to fix up, IN FLASH! */
+	add	r0, r9		/* r0 <- location to fix up in RAM */
+	ldr	r1, [r2, #4]
+	and	r8, r1, #0xff
+	cmp	r8, #23		/* relative fixup? */
+	beq	fixrel
+	cmp	r8, #2		/* absolute fixup? */
+	beq	fixabs
+	/* ignore unknown type of fixup */
+	b	fixnext
+fixabs:
+	/* absolute fix: set location to (offset) symbol value */
+	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
+	add	r1, r10, r1		/* r1 <- address of symbol in table */
+	ldr	r1, [r1, #4]		/* r1 <- symbol value */
+	add	r1, r9			/* r1 <- relocated sym addr */
+	b	fixnext
+fixrel:
+	/* relative fix: increase location by offset */
+	ldr	r1, [r0]
+	add	r1, r1, r9
+fixnext:
+	str	r1, [r0]
+	add	r2, r2, #8	/* each rel.dyn entry is 8 bytes */
 	cmp	r2, r3
-	bne	fixloop
+	blo	fixloop
 #endif
 #endif	/* #ifndef CONFIG_SKIP_RELOCATE_UBOOT */
 
 clear_bss:
 #ifndef CONFIG_PRELOADER
-	ldr	r0, _bss_start
-	ldr	r1, _bss_end
+	ldr	r0, _bss_start_ofs
+	ldr	r1, _bss_end_ofs
 	ldr	r3, _TEXT_BASE		/* Text base */
 	mov	r4, r7			/* reloc addr */
-	sub	r0, r0, r3
 	add	r0, r0, r4
-	sub	r1, r1, r3
 	add	r1, r1, r4
 	mov	r2, #0x00000000		/* clear			    */
 
@@ -287,24 +278,33 @@ clbss_l:str	r2, [r0]		/* clear loop...		    */
  * initialization, now running from RAM.
  */
 #ifdef CONFIG_NAND_SPL
-	ldr     pc, _nand_boot
-
-_nand_boot: .word nand_boot
+	ldr     r0, _nand_boot_ofs
+	adr	r1, _start
+	add	pc, r0, r1
+_nand_boot_ofs
+	: .word nand_boot - _start
 #else
-	ldr	r0, _TEXT_BASE
-	ldr	r2, _board_init_r
-	sub	r2, r2, r0
-	add	r2, r2, r7	/* position from board_init_r in RAM */
+	ldr	r0, _board_init_r_ofs
+	adr	r1, _start
+	add	r0, r0, r1
+	add	lr, r0, r9
 	/* setup parameters for board_init_r */
 	mov	r0, r5		/* gd_t */
 	mov	r1, r7		/* dest_addr */
 	/* jump to it ... */
-	mov	lr, r2
 	mov	pc, lr
 
-_board_init_r: .word board_init_r
+_board_init_r_ofs:
+	.word board_init_r - _start
 #endif
 
+_rel_dyn_start_ofs:
+	.word __rel_dyn_start - _start
+_rel_dyn_end_ofs:
+	.word __rel_dyn_end - _start
+_dynsym_start_ofs:
+	.word __dynsym_start - _start
+
 #else /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
 /*
  * the actual reset code
@@ -333,10 +333,8 @@ relocate:				/* relocate U-Boot to RAM	    */
 	ldr	r1, _TEXT_BASE		/* test if we run from flash or RAM */
 	cmp     r0, r1                  /* don't reloc during debug         */
 	beq     stack_setup
-	ldr	r2, _armboot_start
-	ldr	r3, _bss_start
-	sub	r2, r3, r2		/* r2 <- size of armboot            */
-	add	r2, r0, r2		/* r2 <- source end address         */
+	ldr	r3, _bss_start_ofs	/* r3 <- _bss_start - _start	    */
+	add	r2, r0, r3		/* r2 <- source end address         */
 
 copy_loop:
 	ldmia	r0!, {r3-r10}		/* copy from source address [r0]    */
@@ -360,8 +358,11 @@ stack_setup:
 	bic	sp, sp, #7		/* 8-byte alignment for ABI compliance */
 
 clear_bss:
-	ldr	r0, _bss_start		/* find start of bss segment        */
-	ldr	r1, _bss_end		/* stop here                        */
+	adr	r2, _start
+	ldr	r0, _bss_start_ofs	/* find start of bss segment        */
+	add	r0, r0, r2
+	ldr	r1, _bss_end_ofs	/* stop here                        */
+	add	r1, r1, r2
 	mov	r2, #0x00000000		/* clear                            */
 
 #ifndef CONFIG_PRELOADER
@@ -374,13 +375,16 @@ clbss_l:str	r2, [r0]		/* clear loop...                    */
 	bl red_LED_on
 #endif /* CONFIG_PRELOADER */
 
-	ldr	pc, _start_armboot
+	ldr	r0, _start_armboot_ofs
+	adr	r1, _start
+	add	r0, r0, r1
+	ldr	pc, r0
 
-_start_armboot:
+_start_armboot_ofs:
 #ifdef CONFIG_NAND_SPL
-	.word nand_boot
+	.word nand_boot - _start
 #else
-	.word start_armboot
+	.word start_armboot - _start
 #endif /* CONFIG_NAND_SPL */
 #endif /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
 
@@ -469,7 +473,7 @@ cpu_init_crit:
 	sub	sp, sp, #S_FRAME_SIZE
 	stmia	sp, {r0 - r12}	@ Save user registers (now in svc mode) r0-r12
 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
-	ldr	r2, _armboot_start
+	adr	r2, _start
 	sub	r2, r2, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
 	sub	r2, r2, #(CONFIG_SYS_GBL_DATA_SIZE+8)  @ set base 2 words into abort stack
 #else
@@ -507,7 +511,7 @@ cpu_init_crit:
 
 	.macro get_bad_stack
 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
-	ldr	r13, _armboot_start		@ setup our mode stack
+	adr	r13, _start		@ setup our mode stack
 	sub	r13, r13, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
 	sub	r13, r13, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack
 #else
diff --git a/arch/arm/cpu/arm926ejs/u-boot.lds b/arch/arm/cpu/arm926ejs/u-boot.lds
index 02eb8ca..72f45f8 100644
--- a/arch/arm/cpu/arm926ejs/u-boot.lds
+++ b/arch/arm/cpu/arm926ejs/u-boot.lds
@@ -41,21 +41,19 @@ SECTIONS
 	. = ALIGN(4);
 	.data : {
 		*(.data)
-	__datarel_start = .;
-		*(.data.rel)
-	__datarelrolocal_start = .;
-		*(.data.rel.ro.local)
-	__datarellocal_start = .;
-		*(.data.rel.local)
-	__datarelro_start = .;
-		*(.data.rel.ro)
 	}
 
-	__got_start = .;
 	. = ALIGN(4);
-	.got : { *(.got) }
 
-	__got_end = .;
+	__rel_dyn_start = .;
+	.rel.dyn : { *(.rel.dyn) }
+	__rel_dyn_end = .;
+
+	__dynsym_start = .;
+	.dynsym : { *(.dynsym) }
+
+	. = ALIGN(4);
+
 	. = .;
 	__u_boot_cmd_start = .;
 	.u_boot_cmd : { *(.u_boot_cmd) }
@@ -65,4 +63,10 @@ SECTIONS
 	__bss_start = .;
 	.bss (NOLOAD) : { *(.bss) . = ALIGN(4); }
 	_end = .;
+
+	/DISCARD/ : { *(.dynstr*) }
+	/DISCARD/ : { *(.dynamic*) }
+	/DISCARD/ : { *(.plt*) }
+	/DISCARD/ : { *(.interp*) }
+	/DISCARD/ : { *(.gnu*) }
 }
diff --git a/arch/arm/include/asm/config.h b/arch/arm/include/asm/config.h
index 4e8dfd7..8d3eb10 100644
--- a/arch/arm/include/asm/config.h
+++ b/arch/arm/include/asm/config.h
@@ -21,8 +21,6 @@
 #ifndef _ASM_CONFIG_H_
 #define _ASM_CONFIG_H_
 
-#if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
 /* Relocation to SDRAM works on all ARM boards */
 #define CONFIG_RELOC_FIXUP_WORKS
 #endif
-#endif
diff --git a/arch/arm/include/asm/u-boot-arm.h b/arch/arm/include/asm/u-boot-arm.h
index faf800a..4ac4f61 100644
--- a/arch/arm/include/asm/u-boot-arm.h
+++ b/arch/arm/include/asm/u-boot-arm.h
@@ -30,18 +30,18 @@
 #define _U_BOOT_ARM_H_	1
 
 /* for the following variables, see start.S */
-extern ulong _bss_start;	/* code + data end == BSS start */
-extern ulong _bss_end;		/* BSS end */
+extern ulong _bss_start_ofs;	/* BSS start relative to _start */
+extern ulong _bss_end_ofs;		/* BSS end relative to _start */
 extern ulong IRQ_STACK_START;	/* top of IRQ stack */
 extern ulong FIQ_STACK_START;	/* top of FIQ stack */
 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
-extern ulong _armboot_start;	/* code start */
+extern ulong _armboot_start_ofs;	/* code start */
 #else
 extern ulong _TEXT_BASE;	/* code start */
-extern ulong _datarel_start;
-extern ulong _datarelrolocal_start;
-extern ulong _datarellocal_start;
-extern ulong _datarelro_start;
+extern ulong _datarel_start_ofs;
+extern ulong _datarelrolocal_start_ofs;
+extern ulong _datarellocal_start_ofs;
+extern ulong _datarelro_start_ofs;
 extern ulong IRQ_STACK_START_IN;	/* 8 bytes in IRQ stack */
 #endif
 
diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c
index 5f2dfd0..e411d93 100644
--- a/arch/arm/lib/board.c
+++ b/arch/arm/lib/board.c
@@ -147,7 +147,7 @@ static int display_banner (void)
 #else
 	       _armboot_start,
 #endif
-	       _bss_start, _bss_end);
+	       _bss_start_ofs+_TEXT_BASE, _bss_end_ofs+_TEXT_BASE);
 #ifdef CONFIG_MODEM_SUPPORT
 	debug ("Modem Support enabled\n");
 #endif
@@ -517,7 +517,7 @@ void board_init_f (ulong bootflag)
 
 	memset ((void*)gd, 0, sizeof (gd_t));
 
-	gd->mon_len = _bss_end - _TEXT_BASE;
+	gd->mon_len = _bss_end_ofs;
 
 	for (init_fnc_ptr = init_sequence; *init_fnc_ptr; ++init_fnc_ptr) {
 		if ((*init_fnc_ptr)() != 0) {
@@ -679,6 +679,7 @@ static char *failed = "*** failed ***\n";
  *
  ************************************************************************
  */
+
 void board_init_r (gd_t *id, ulong dest_addr)
 {
 	char *s;
@@ -702,7 +703,7 @@ void board_init_r (gd_t *id, ulong dest_addr)
 
 	gd->flags |= GD_FLG_RELOC;	/* tell others: relocation done */
 
-	monitor_flash_len = _bss_start - _TEXT_BASE;
+	monitor_flash_len = _bss_start_ofs;
 	debug ("monitor flash len: %08lX\n", monitor_flash_len);
 	board_init();	/* Setup chipselects */
 
@@ -914,6 +915,7 @@ extern void davinci_eth_set_mac_addr (const u_int8_t *addr);
 
 	/* NOTREACHED - no way out of command loop except booting */
 }
+
 #endif /* defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
 
 void hang (void)
diff --git a/doc/README.arm-relocation b/doc/README.arm-relocation
index e3ed60e..b46347b 100644
--- a/doc/README.arm-relocation
+++ b/doc/README.arm-relocation
@@ -1,49 +1,54 @@
 To make relocation on arm working, the following changes are done:
 
-Add new compilerflag:
+At arch level: add linker flag -pie
 
--fPIC
+	This causes the linker to generate fixup tables .rel.dyn and .dynsym,
+	which must be applied to the relocated image before transferring
+	control to it.
 
-	-> compiler generates position independent code
+	These fixups are described in the ARM ELF documentation as type 23
+	(program-base-relative) and 2 (symbol-relative)
 
-changes in board code:
+At cpu level: modify linker file and add a relocation and fixup loop
 
-- dram_init:
-  - bd pointer is now at this point not accessible, so only
-    detect the real dramsize, and store it in gd->ram_size.
-    best detected with get_ram_size();
-    ToDo: move there also the dram initialization on boards where
-          it is possible.
-  - setup the bd_t dram bank info in the new function
-    dram_init_banksize().
+	the linker file must be modified to include the .rel.dyn and .dynsym
+	tables in the binary image, and to provide symbols for the relocation
+	code to access these tables
 
-- board.c code is adapted from ppc code
+	The relocation and fixup loop must be executed after executing
+	board_init_f at initial location and before executing board_init_r
+	at final location.
 
-- undef CONFIG_RELOC_FIXUP_WORKS
+At board level:
 
-  -> cmdtabl, and subcommand table must be handled from "hand"
-     collected in section "__datarellocal_start".
+	dram_init(): bd pointer is now at this point not accessible, so only
+	detect the real dramsize, and store it in gd->ram_size. Bst detected
+	with get_ram_size().
 
-  - How To fixup the sections:
+TODO:	move also dram initialization there on boards where it is possible.
 
-    __datarel_start, __datarelrolocal_start, __datarellocal_start and
-    __datarelro_start
+	Setup of the the bd_t dram bank info is done in the new function
+	dram_init_banksize() called after bd is accessible.
 
-    automatically? Then it should be possible to define again
-    CONFIG_RELOC_FIXUP_WORKS
+At lib level:
 
-- irq stack setup is now not longer on a fix position, instead it is
-  calculated in board_init_f, and stored in gd->irq_sp
+	Board.c code is adapted from ppc code
 
--------------------------------------------------------------------------------------
+At config level:
 
-To compile a board without relocation, define CONFIG_SYS_ARM_WITHOUT_RELOC
-This possibility will removed!! So please fix your board to compile without
-CONFIG_SYS_ARM_WITHOUT_RELOC defined!!!
+	Define CONFIG_RELOC_FIXUP_WORKS.
+	Undefine CONFIG_SYS_ARM_WITHOUT_RELOC
 
--------------------------------------------------------------------------------------
+* WARNING ** WARNING ** WARNING ** WARNING ** WARNING ** WARNING ** WARNING *
+
+Boards which are not fixed to support relocation will be REMOVED!
+
+Eventually, CONFIG_SYS_ARM_WITHOUT_RELOC and CONFIG_RELOC_FIXUP_WORKS will
+disappear and boards which have to migrated to relocation will disappear too.
+
+-----------------------------------------------------------------------------
 
-For boards which boot from nand_spl, it is possible to save a copy
+For boards which boot from nand_spl, it is possible to save one copy
 if TEXT_BASE == relocation address! This prevents that uboot code
 is copied again in relocate_code().
 
@@ -64,9 +69,9 @@ f) u-boot code steps through board_init_f() and calculates
 If TEXT_BASE == relocation address, the copying of u-boot
 in f) could be saved.
 
--------------------------------------------------------------------------------------
+-----------------------------------------------------------------------------
 
-ToDo:
+TODO
 
 - fill in bd_t infos (check)
 - adapt all boards
@@ -80,7 +85,7 @@ ToDo:
 - new function dram_init_banksize() is actual board specific. Maybe
   we make a weak default function in arch/arm/lib/board.c ?
 
--------------------------------------------------------------------------------------
+-----------------------------------------------------------------------------
 
 Relocation with NAND_SPL (example for the tx25):
 
@@ -98,158 +103,11 @@ Relocation with NAND_SPL (example for the tx25):
   from the nand_spl code), no need to copy, just go on with bss clear
   and jump to board_init_r.
 
--------------------------------------------------------------------------------------
-
-Relocation:
-How to translate flash addresses in GOT to ram addresses.
-This is automagically done from code, but this example
-shows, how this magic code works ;-)
-(example on the qong board)
-
-Find a variable:
-
-a) search it in System.map
-(for example flash_info)
-
-a005b4c0 B BootpID
-a005b4c4 B BootpTry
-a005b4c8 b slave
-a005b4cc B flash_info
-^^^^^^^^
-a005c908 b saved_sector.4002
-a005c910 b cfi_mtd_info
-a005c9c0 b cfi_mtd_names
-a005c9d0 B mtd_table
-
----------------------------------------
-
-b) create hexdump from u-boot code:
-
-hexdump -C u-boot > gnlmpfhex
-
----------------------------------------
-
-c) search the variables address in the hexdump
-
-
-*
-0005fc80  00 00 00 00 00 00 00 00  2c 06 01 a0 18 cd 05 a0  |........,.......|
-0005fc90  9c d4 05 a0 bc b4 05 a0  1c 7f 05 a0 f0 05 01 a0  |................|
-0005fca0  08 5a 04 a0 1c ab 05 a0  ec a4 05 a0 98 c3 01 a0  |.Z..............|
-0005fcb0  a0 d6 05 a0 04 71 05 a0  c0 f9 00 a0 3c cd 05 a0  |.....q......<...|
-0005fcc0  cc b4 05 a0 f0 fa 00 a0  f0 d6 05 a0 10 86 05 a0  |................|
-          ^^^^^^^^^^^
-0005fcd0  a4 16 06 a0 dc 64 05 a0  18 86 05 a0 52 48 05 a0  |.....d......RH..|
-0005fce0  c0 86 05 a0 24 6e 02 a0  b4 6c 05 a0 b0 94 01 a0  |....$n...l......|
-0005fcf0  1c 86 05 a0 50 85 05 a0  d4 0c 06 a0 bc 0b 06 a0  |....P...........|
-
-
--> 0005fcc0
-
-----------------------------------------
-
-d) know we calculate this address in RAM
-
-
-  8ff08000	(new address of code in RAM *1)
-
-+ 0005fcc0
-
-- 00008000	(offset of text *2)
-
-----------
-
-  8ff5fcc0	-> Addr GOT in RAM
-
-*1:
-activate debug and look for the line:
-Now running in RAM - U-Boot at: 8ff08000
-                                ^^^^^^^^
-                                new address of u-boot code in RAM
-
-*2:
-Section Headers:
-  [Nr] Name              Type            Addr     Off    Size   ES Flg Lk Inf Al
-  [ 0]                   NULL            00000000 000000 000000 00      0   0  0
-  [ 1] .text             PROGBITS        a0000000 008000 04599c 00  AX  0   0 32
-                                                  ^^^^^^
-                                                  Offset of text
+-----------------------------------------------------------------------------
 
-----------------------------------------
+How ELF relocations 23 and 2 work.
 
-e) now we look in 8ff5fcc0 (RAM)
-
-
-QongEVB>md 0x8ff5fcc0
-8ff5fcc0 : a005b4cc a000faf0 a005d6f0 a0058610  ................
-           ^^^^^^^^
-           Bingo, here we have the old flash address (when relocation
-           is working, here is the fixed ram address. see @ f, how
-           it gets calculated)
-
-
-----------------------------------------
-
-f) now translate it in the new RAM address
-
-  a005b4cc
-
-- a0000000     TextBase
-
-+ 8ff08000     new address of u-boot in ram
-----------
-  8ff634cc
-
-QongEVB>mm 0x8ff5fcc0 0x8ff634cc 1
-QongEVB>md 0x8ff5fcc0
-8ff5fcc0 : 8ff634cc a000faf0 a005d6f0 a0058610  .4..............
-8ff5fcd0 : a00616a4 a00564dc a0058618 a0054852  .....d......RH..
-
-As this must be done for all address in the GOT, the u-boot
-code did this automagically ... :-)
-
-----------------------------------------------
-
-g) check if the new address is really in the bss section:
-
-bss start:
-8ff6054c	(8ff08000 + 0005854C monitorlen)
-
-bss end:
-8ff698ac	(8ff08000 + 618AC)
-
-8ff634cc is in bss :-)
-
-----------------------------------------------
-
-h) u-boot prints:
-
-important  addresses:
-
-U-Boot code: A0000000 -> A005854C  BSS: -> A00618AC	TextBase 0xa0000000
-Now running in RAM - U-Boot at: 8ff08000		relocBase 0x8ff08000
-
-
----------
-
-U-Boot 2010.06-rc2-00002-gf8fbb25-dirty (Jun 18 2010 - 17:07:19)
-
-U-Boot code: A0000000 -> A005854C  BSS: -> A00618AC
-CPU:   Freescale i.MX31 at 398 MHz
-Board: DAVE/DENX Qong
-mon: FFFFFFFF gd->monLen: 000618AC
-Top of RAM usable for U-Boot at: 90000000
-LCD panel info: 640 x 480, 16 bit/pix
-Reserving 600k for LCD Framebuffer at: 8ff6a000
-Reserving 390k for U-Boot at: 8ff08000
-Reserving 1280k for malloc() at: 8fdc8000
-Reserving 28 Bytes for Board Info at: 8fdc7fe4
-Reserving 48 Bytes for Global Data at: 8fdc7fb4
-New Stack Pointer is: 8fdc7fb0
-RAM Configuration:
-Bank #0: 80000000 256 MiB
-mon: 0005854C gd->monLen: 000618AC
-Now running in RAM - U-Boot at: 8ff08000
+TBC
 
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