[U-Boot] [PATCH] arm: Add option to disable code relocation

[Simon Glass]

This permits disabling the code relation in U-Boot which is useful when
debugging with an ICE.

To use it define CONFIG_SYS_SKIP_ARM_RELOCATION in your board.

Signed-off-by: Simon Glass <sjg at chromium.org>
---
 arch/arm/config.mk                 |    2 ++
 arch/arm/cpu/armv7/start.S         |    3 +--
 arch/arm/include/asm/global_data.h |    3 +++
 arch/arm/lib/board.c               |   10 ++++++++++
 4 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/arm/config.mk b/arch/arm/config.mk
index 45f9dca..46b52af 100644
--- a/arch/arm/config.mk
+++ b/arch/arm/config.mk
@@ -79,5 +79,7 @@ endif
 
 # needed for relocation
 ifndef CONFIG_NAND_SPL
+ifndef CONFIG_SYS_SKIP_ARM_RELOCATION
 LDFLAGS_u-boot += -pie
 endif
+endif
diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
index ef08a55..82eac7c 100644
--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -183,8 +183,7 @@ stack_setup:
 	mov	sp, r4
 
 	adr	r0, _start
-	cmp	r0, r6
-	moveq	r9, #0		/* no relocation. relocation offset(r9) = 0 */
+	subs	r9, r6, r0		/* r9 <- relocation offset */
 	beq	clear_bss		/* skip relocation */
 	mov	r1, r6			/* r1 <- scratch for copy_loop */
 	ldr	r3, _image_copy_end_ofs
diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
index c3ff789..23a6077 100644
--- a/arch/arm/include/asm/global_data.h
+++ b/arch/arm/include/asm/global_data.h
@@ -77,6 +77,9 @@ typedef	struct	global_data {
 	unsigned long	tlb_addr;
 #endif
 	const void	*fdt_blob;	/* Our device tree, NULL if none */
+#ifdef CONFIG_SYS_SKIP_ARM_RELOCATION
+	ulong		malloc_end;	/* End of malloc region (addr + 1) */
+#endif
 	void		**jt;		/* jump table */
 	char		env_buf[32];	/* buffer for getenv() before reloc. */
 #if defined(CONFIG_POST) || defined(CONFIG_LOGBUFFER)
diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c
index 3d78274..81293c3 100644
--- a/arch/arm/lib/board.c
+++ b/arch/arm/lib/board.c
@@ -355,6 +355,7 @@ void board_init_f(ulong bootflag)
 #endif /* CONFIG_FB_ADDR */
 #endif /* CONFIG_LCD */
 
+#ifndef CONFIG_SYS_SKIP_ARM_RELOCATION
 	/*
 	 * reserve memory for U-Boot code, data & bss
 	 * round down to next 4 kB limit
@@ -363,6 +364,7 @@ void board_init_f(ulong bootflag)
 	addr &= ~(4096 - 1);
 
 	debug("Reserving %ldk for U-Boot at: %08lx\n", gd->mon_len >> 10, addr);
+#endif
 
 #ifndef CONFIG_SPL_BUILD
 	/*
@@ -419,6 +421,10 @@ void board_init_f(ulong bootflag)
 	dram_init_banksize();
 	display_dram_config();	/* and display it */
 
+#ifdef CONFIG_SYS_SKIP_ARM_RELOCATION
+	gd->malloc_end = addr;
+	addr = _TEXT_BASE;
+#endif
 	gd->relocaddr = addr;
 	gd->start_addr_sp = addr_sp;
 	gd->reloc_off = addr - _TEXT_BASE;
@@ -478,7 +484,11 @@ void board_init_r(gd_t *id, ulong dest_addr)
 #endif
 
 	/* The Malloc area is immediately below the monitor copy in DRAM */
+#ifdef CONFIG_SYS_SKIP_ARM_RELOCATION
+	malloc_start = gd->malloc_end - TOTAL_MALLOC_LEN;
+#else
 	malloc_start = dest_addr - TOTAL_MALLOC_LEN;
+#endif
 	mem_malloc_init (malloc_start, TOTAL_MALLOC_LEN);
 
 #if !defined(CONFIG_SYS_NO_FLASH)
-- 
1.7.7.3