* [PATCH 1/3] ARM lowlevel: Update function documentation
2012-09-10 7:56 [PATCH v2] ARM lowlevel Sascha Hauer
@ 2012-09-10 7:56 ` Sascha Hauer
2012-09-10 7:56 ` [PATCH 2/3] ARM: Add assembler function to get runtime offset Sascha Hauer
2012-09-10 7:56 ` [PATCH 3/3] ARM lowlevel: Use get_runtime_offset Sascha Hauer
2 siblings, 0 replies; 4+ messages in thread
From: Sascha Hauer @ 2012-09-10 7:56 UTC (permalink / raw)
To: barebox
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
arch/arm/cpu/start-pbl.c | 3 +++
arch/arm/cpu/start-reset.c | 3 +++
arch/arm/cpu/start.c | 5 ++++-
3 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/arch/arm/cpu/start-pbl.c b/arch/arm/cpu/start-pbl.c
index 932a3da..09a1940 100644
--- a/arch/arm/cpu/start-pbl.c
+++ b/arch/arm/cpu/start-pbl.c
@@ -36,6 +36,9 @@
unsigned long free_mem_ptr;
unsigned long free_mem_end_ptr;
+/*
+ * First instructions in the pbl image
+ */
void __naked __section(.text_head_entry) pbl_start(void)
{
barebox_arm_head();
diff --git a/arch/arm/cpu/start-reset.c b/arch/arm/cpu/start-reset.c
index e0df676..fcfdce6 100644
--- a/arch/arm/cpu/start-reset.c
+++ b/arch/arm/cpu/start-reset.c
@@ -29,6 +29,9 @@
/*
* The actual reset vector. This code is position independent and usually
* does not run at the address it's linked at.
+ *
+ * This is either executed in the pbl image (if enabled) or in the regular
+ * image.
*/
void __naked __bare_init reset(void)
{
diff --git a/arch/arm/cpu/start.c b/arch/arm/cpu/start.c
index 07e7dfe..e43ff9c 100644
--- a/arch/arm/cpu/start.c
+++ b/arch/arm/cpu/start.c
@@ -30,7 +30,7 @@
#ifdef CONFIG_PBL_IMAGE
/*
- * First function in the pbl image. We get here from
+ * First function in the uncompressed image. We get here from
* the pbl.
*/
void __naked __section(.text_entry) start(void)
@@ -47,6 +47,9 @@ void __naked __section(.text_entry) start(void)
}
#else
+/*
+ * First function in the image without pbl support
+ */
void __naked __section(.text_entry) start(void)
{
barebox_arm_head();
--
1.7.10.4
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^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH 2/3] ARM: Add assembler function to get runtime offset
2012-09-10 7:56 [PATCH v2] ARM lowlevel Sascha Hauer
2012-09-10 7:56 ` [PATCH 1/3] ARM lowlevel: Update function documentation Sascha Hauer
@ 2012-09-10 7:56 ` Sascha Hauer
2012-09-10 7:56 ` [PATCH 3/3] ARM lowlevel: Use get_runtime_offset Sascha Hauer
2 siblings, 0 replies; 4+ messages in thread
From: Sascha Hauer @ 2012-09-10 7:56 UTC (permalink / raw)
To: barebox
This function returns the offset between the address barebox is linked at
and the address barebox is currently running at.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
arch/arm/include/asm/barebox-arm.h | 1 +
arch/arm/lib/Makefile | 2 ++
arch/arm/lib/runtime-offset.S | 17 +++++++++++++++++
3 files changed, 20 insertions(+)
create mode 100644 arch/arm/lib/runtime-offset.S
diff --git a/arch/arm/include/asm/barebox-arm.h b/arch/arm/include/asm/barebox-arm.h
index b880dd4..3639365 100644
--- a/arch/arm/include/asm/barebox-arm.h
+++ b/arch/arm/include/asm/barebox-arm.h
@@ -42,5 +42,6 @@ extern char __ll_return[];
void board_init_lowlevel(void);
void board_init_lowlevel_return(void);
void arch_init_lowlevel(void);
+uint32_t get_runtime_offset(void);
#endif /* _BAREBOX_ARM_H_ */
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 9d0ff7a..2e624cd 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -16,6 +16,8 @@ obj-y += lib1funcs.o
obj-y += ashrdi3.o
obj-y += ashldi3.o
obj-y += lshrdi3.o
+obj-y += runtime-offset.o
+pbl-y += runtime-offset.o
obj-$(CONFIG_ARM_OPTIMZED_STRING_FUNCTIONS) += memcpy.o
obj-$(CONFIG_ARM_OPTIMZED_STRING_FUNCTIONS) += memset.o
obj-$(CONFIG_ARM_UNWIND) += unwind.o
diff --git a/arch/arm/lib/runtime-offset.S b/arch/arm/lib/runtime-offset.S
new file mode 100644
index 0000000..ffa668c
--- /dev/null
+++ b/arch/arm/lib/runtime-offset.S
@@ -0,0 +1,17 @@
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+/*
+ * Get the offset between the link address and the address
+ * we are currently running at.
+ */
+ENTRY(get_runtime_offset)
+1: adr r0, 1b
+ ldr r1, linkadr
+ subs r0, r1, r0
+THUMB( subs r0, r0, #1)
+ mov pc, lr
+
+linkadr:
+.word get_runtime_offset
+ENDPROC(get_runtime_offset)
--
1.7.10.4
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^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 3/3] ARM lowlevel: Use get_runtime_offset
2012-09-10 7:56 [PATCH v2] ARM lowlevel Sascha Hauer
2012-09-10 7:56 ` [PATCH 1/3] ARM lowlevel: Update function documentation Sascha Hauer
2012-09-10 7:56 ` [PATCH 2/3] ARM: Add assembler function to get runtime offset Sascha Hauer
@ 2012-09-10 7:56 ` Sascha Hauer
2 siblings, 0 replies; 4+ messages in thread
From: Sascha Hauer @ 2012-09-10 7:56 UTC (permalink / raw)
To: barebox
The current approach to get the offset between link and runtime address
is fragile. It requires a big fat comment to put no code above it and it
requires an extra linker section. Instead use a small assembler function.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
arch/arm/cpu/start-pbl.c | 12 +++---------
arch/arm/cpu/start.c | 12 +++---------
arch/arm/include/asm/barebox-arm.h | 1 -
arch/arm/lib/barebox.lds.S | 2 --
arch/arm/pbl/zbarebox.lds.S | 2 --
5 files changed, 6 insertions(+), 23 deletions(-)
diff --git a/arch/arm/cpu/start-pbl.c b/arch/arm/cpu/start-pbl.c
index 09a1940..5a6b99b 100644
--- a/arch/arm/cpu/start-pbl.c
+++ b/arch/arm/cpu/start-pbl.c
@@ -152,23 +152,17 @@ static void barebox_uncompress(void *compressed_start, unsigned int len)
* Board code can jump here by either returning from board_init_lowlevel
* or by calling this function directly.
*/
-void __naked __section(.text_ll_return) board_init_lowlevel_return(void)
+void __naked board_init_lowlevel_return(void)
{
- uint32_t r, addr, offset;
+ uint32_t r, offset;
uint32_t pg_start, pg_end, pg_len;
- /*
- * Get runtime address of this function. Do not
- * put any code above this.
- */
- __asm__ __volatile__("1: adr %0, 1b":"=r"(addr));
-
/* Setup the stack */
r = STACK_BASE + STACK_SIZE - 16;
__asm__ __volatile__("mov sp, %0" : : "r"(r));
/* Get offset between linked address and runtime address */
- offset = (uint32_t)__ll_return - addr;
+ offset = get_runtime_offset();
pg_start = (uint32_t)&input_data - offset;
pg_end = (uint32_t)&input_data_end - offset;
diff --git a/arch/arm/cpu/start.c b/arch/arm/cpu/start.c
index e43ff9c..1c6a7dd 100644
--- a/arch/arm/cpu/start.c
+++ b/arch/arm/cpu/start.c
@@ -59,22 +59,16 @@ void __naked __section(.text_entry) start(void)
* Board code can jump here by either returning from board_init_lowlevel
* or by calling this function directly.
*/
-void __naked __section(.text_ll_return) board_init_lowlevel_return(void)
+void __naked board_init_lowlevel_return(void)
{
- uint32_t r, addr, offset;
-
- /*
- * Get runtime address of this function. Do not
- * put any code above this.
- */
- __asm__ __volatile__("1: adr %0, 1b":"=r"(addr));
+ uint32_t r, offset;
/* Setup the stack */
r = STACK_BASE + STACK_SIZE - 16;
__asm__ __volatile__("mov sp, %0" : : "r"(r));
/* Get offset between linked address and runtime address */
- offset = (uint32_t)__ll_return - addr;
+ offset = get_runtime_offset();
/* relocate to link address if necessary */
if (offset)
diff --git a/arch/arm/include/asm/barebox-arm.h b/arch/arm/include/asm/barebox-arm.h
index 3639365..a71f420 100644
--- a/arch/arm/include/asm/barebox-arm.h
+++ b/arch/arm/include/asm/barebox-arm.h
@@ -37,7 +37,6 @@ int board_init(void);
int dram_init (void);
extern char __exceptions_start[], __exceptions_stop[];
-extern char __ll_return[];
void board_init_lowlevel(void);
void board_init_lowlevel_return(void);
diff --git a/arch/arm/lib/barebox.lds.S b/arch/arm/lib/barebox.lds.S
index a69013f..40af705 100644
--- a/arch/arm/lib/barebox.lds.S
+++ b/arch/arm/lib/barebox.lds.S
@@ -40,8 +40,6 @@ SECTIONS
_stext = .;
_text = .;
*(.text_entry*)
- __ll_return = .;
- *(.text_ll_return*)
__bare_init_start = .;
*(.text_bare_init*)
__bare_init_end = .;
diff --git a/arch/arm/pbl/zbarebox.lds.S b/arch/arm/pbl/zbarebox.lds.S
index 2dca278..37af4e9 100644
--- a/arch/arm/pbl/zbarebox.lds.S
+++ b/arch/arm/pbl/zbarebox.lds.S
@@ -39,8 +39,6 @@ SECTIONS
_stext = .;
_text = .;
*(.text_head_entry*)
- __ll_return = .;
- *(.text_ll_return*)
__bare_init_start = .;
*(.text_bare_init*)
__bare_init_end = .;
--
1.7.10.4
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^ permalink raw reply [flat|nested] 4+ messages in thread