[U-Boot] [PATCH] arm: add IPL support

[U-Boot] [PATCH] arm: add IPL support

[Kuo-Jung Su]

Initial Program Loader (IPL) usually runs with .text and .rodata
in ROM, while .data and .bss reside in RAM.

This patch uses the AT keyword to specify load address,
and a small code snippet in crt0.S to restore .data section
at runtime.

Example usage:
Assume the target device has a 4KB ROM at 0x00000000 and a
4KB SRAM at 0xA0000000, the IPL/SPL config could be:

#define CONFIG_SPL_MAX_SIZE  0x1000 /* text + data, no bss */
#define CONFIG_SPL_TEXT_BASE 0x00000000
#define CONFIG_SPL_DATA_BASE 0xA0000000
#define CONFIG_SPL_STACK     0xA0001000

Signed-off-by: Kuo-Jung Su <dantesu@gmail.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
---
 README                      |   10 ++++++++++
 arch/arm/cpu/u-boot-spl.lds |   26 ++++++++++++++++++++++++--
 arch/arm/lib/crt0.S         |   22 ++++++++++++++++++++++
 spl/Makefile                |    6 ++++++
 4 files changed, 62 insertions(+), 2 deletions(-)

diff --git a/README b/README
index a8d3039..992064a 100644
--- a/README
+++ b/README
@@ -3094,6 +3094,16 @@ FIT uImage format:
 		Address to relocate to.  If unspecified, this is equal to
 		CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).

+		CONFIG_SPL_DATA_BASE
+		Link address for the .data and .bss within the SPL binary.
+		CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_DATA_BASE
+		must not be both defined at the same time.
+
+		CONFIG_SPL_DATA_MAX_SIZE
+		Maximum size in memory allocated to the SPL .data + .bss.
+		When defined, the linker checks that the actual memory used
+		by SPL from __data_start to __bss_end does not exceed it.
+
 		CONFIG_SPL_BSS_START_ADDR
 		Link address for the BSS within the SPL binary.

diff --git a/arch/arm/cpu/u-boot-spl.lds b/arch/arm/cpu/u-boot-spl.lds
index 36cc54a..ea6284f 100644
--- a/arch/arm/cpu/u-boot-spl.lds
+++ b/arch/arm/cpu/u-boot-spl.lds
@@ -26,15 +26,28 @@ SECTIONS
 	.rodata : { *(SORT_BY_ALIGNMENT(SORT_BY_NAME(.rodata*))) }

 	. = ALIGN(4);
-	.data : {
+
+#if defined(CONFIG_SPL_DATA_BASE)
+	__image_copy_end = .;
+
+	.data : AT ( __image_copy_end )
+#else
+	.data :
+#endif
+	{
+		__data_start = .;
 		*(.data*)
+		. = ALIGN(4);
+		__data_end = .;
 	}

 	. = ALIGN(4);

 	. = .;

+#if !defined(CONFIG_SPL_DATA_BASE)
 	__image_copy_end = .;
+#endif

 	.rel.dyn : {
 		__rel_dyn_start = .;
@@ -59,11 +72,20 @@ SECTIONS
 	/DISCARD/ : { *(.gnu*) }
 }

-#if defined(CONFIG_SPL_MAX_SIZE)
+#if defined(CONFIG_SPL_MAX_SIZE) && defined(CONFIG_SPL_DATA_BASE)
+ASSERT((__image_copy_end - __image_copy_start) + \
+	(__data_end - __data_start) < (CONFIG_SPL_MAX_SIZE), \
+	"SPL image too big");
+#elif defined(CONFIG_SPL_MAX_SIZE)
 ASSERT(__image_copy_end - __image_copy_start < (CONFIG_SPL_MAX_SIZE), \
 	"SPL image too big");
 #endif

+#if defined(CONFIG_SPL_DATA_MAX_SIZE)
+ASSERT(__bss_end - __data_start < (CONFIG_SPL_DATA_MAX_SIZE), \
+	"SPL image DATA plus BSS too big");
+#endif
+
 #if defined(CONFIG_SPL_BSS_MAX_SIZE)
 ASSERT(__bss_end - __bss_start < (CONFIG_SPL_BSS_MAX_SIZE), \
 	"SPL image BSS too big");
diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S
index ac54b93..46d0e03 100644
--- a/arch/arm/lib/crt0.S
+++ b/arch/arm/lib/crt0.S
@@ -58,6 +58,28 @@
 ENTRY(_main)

 /*
+ * Restore .data (initialized) section
+ */
+
+#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_DATA_BASE)
+
+	/* Load values from the board-specific linker script. */
+	ldr r0, =__image_copy_end /* source start address */
+	ldr r1, =__data_start
+	ldr r2, =__data_end
+	sub r2, r2, r1
+	add r2, r0, r2            /* source end address   */
+	ldr r1, =CONFIG_SPL_DATA_BASE
+
+data_copy:
+	ldmia r0!, {r3-r10}       /* copy from source address [r0] */
+	stmia r1!, {r3-r10}       /* copy to   target address [r1] */
+	cmp   r0, r2              /* until source end addreee [r2] */
+	blo   data_copy
+
+#endif	/* CONFIG_SPL_BUILD && CONFIG_SPL_DATA_BASE */
+
+/*
  * Set up initial C runtime environment and call board_init_f(0).
  */

diff --git a/spl/Makefile b/spl/Makefile
index 29d7818..540ef8c 100644
--- a/spl/Makefile
+++ b/spl/Makefile
@@ -54,6 +54,12 @@ ifeq ($(CPU),mpc85xx)
 START += $(START_PATH)/resetvec.o
 endif

+ifdef CONFIG_SPL_DATA_BASE
+LDFLAGS += -Ttext $(CONFIG_SPL_TEXT_BASE) -Tdata $(CONFIG_SPL_DATA_BASE)
+else
+LDFLAGS += -Ttext $(CONFIG_SPL_TEXT_BASE)
+endif
+
 LIBS-y += arch/$(ARCH)/lib/

 LIBS-y += $(CPUDIR)/
--
1.7.9.5

[U-Boot] [PATCH] arm: add IPL support

[Tom Rini]

On Wed, Dec 04, 2013 at 11:50:48AM +0800, Kuo-Jung Su wrote:

> Initial Program Loader (IPL) usually runs with .text and .rodata
> in ROM, while .data and .bss reside in RAM.
> 
> This patch uses the AT keyword to specify load address,
> and a small code snippet in crt0.S to restore .data section
> at runtime.
> 
> Example usage:
> Assume the target device has a 4KB ROM at 0x00000000 and a
> 4KB SRAM at 0xA0000000, the IPL/SPL config could be:
> 
> #define CONFIG_SPL_MAX_SIZE  0x1000 /* text + data, no bss */
> #define CONFIG_SPL_TEXT_BASE 0x00000000
> #define CONFIG_SPL_DATA_BASE 0xA0000000
> #define CONFIG_SPL_STACK     0xA0001000
> 
> Signed-off-by: Kuo-Jung Su <dantesu@gmail.com>
> Cc: Albert Aribaud <albert.u.boot@aribaud.net>

Can you provide an example user of this functionality?  Thanks.

-- 
Tom
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[U-Boot] [PATCH] arm: add IPL support

[Kuo-Jung Su]

2013/12/6 Tom Rini <trini@ti.com>:
> On Wed, Dec 04, 2013 at 11:50:48AM +0800, Kuo-Jung Su wrote:
>
>> Initial Program Loader (IPL) usually runs with .text and .rodata
>> in ROM, while .data and .bss reside in RAM.
>>
>> This patch uses the AT keyword to specify load address,
>> and a small code snippet in crt0.S to restore .data section
>> at runtime.
>>
>> Example usage:
>> Assume the target device has a 4KB ROM at 0x00000000 and a
>> 4KB SRAM at 0xA0000000, the IPL/SPL config could be:
>>
>> #define CONFIG_SPL_MAX_SIZE  0x1000 /* text + data, no bss */
>> #define CONFIG_SPL_TEXT_BASE 0x00000000
>> #define CONFIG_SPL_DATA_BASE 0xA0000000
>> #define CONFIG_SPL_STACK     0xA0001000
>>
>> Signed-off-by: Kuo-Jung Su <dantesu@gmail.com>
>> Cc: Albert Aribaud <albert.u.boot@aribaud.net>
>
> Can you provide an example user of this functionality?  Thanks.
>
> --
> Tom

If you're looking for a real device, unfortunately there is no such
device right now,
it's a shiny new design which just came out last week.

If you're looking for a way for verification:

1. A real device with a NOR flash for ROM emulation. (e.g., Faraday A369 EVB)

2. A virtual device emulator. (e.g., Qemu)

   This is the best option for you, the Qemu model for Faraday A369 is
available at my github account.
   Please use the command bellow to grab the source tree if necessary.

   $ git clone -b qemu-1.5.1 https://github.com/dantesu1218/qemu.git
   $ cd qemu
   $ ./configure --target-list=arm-softmmu
   $ make

   The example IPL code for the up-coming Faraday A369 U-boot is also available:

   $ git clone -b u-boot-2014.01 https://github.com/dantesu1218/u-boot.git
   $ cd u-boot
   $ make a369evb_ipl_config
   $ make

   You could also directly grab  the pre-built binaries for quick verification.

   $ wget https://drive.google.com/file/d/0BwfiewvSmUgAMlBnUkZQb3FMVkE/edit?usp=sharing
   $ tar xf u-boot-a369-ipl.tar.bz2
   $ cd u-boot-a369-ipl
   $ make

-- 
Best wishes,
Kuo-Jung Su

[U-Boot] [PATCH] arm: add IPL support

[Tom Rini]

On Mon, Dec 09, 2013 at 04:07:29PM +0800, Kuo-Jung Su wrote:
> 2013/12/6 Tom Rini <trini@ti.com>:
> > On Wed, Dec 04, 2013 at 11:50:48AM +0800, Kuo-Jung Su wrote:
> >
> >> Initial Program Loader (IPL) usually runs with .text and .rodata
> >> in ROM, while .data and .bss reside in RAM.
> >>
> >> This patch uses the AT keyword to specify load address,
> >> and a small code snippet in crt0.S to restore .data section
> >> at runtime.
> >>
> >> Example usage:
> >> Assume the target device has a 4KB ROM at 0x00000000 and a
> >> 4KB SRAM at 0xA0000000, the IPL/SPL config could be:
> >>
> >> #define CONFIG_SPL_MAX_SIZE  0x1000 /* text + data, no bss */
> >> #define CONFIG_SPL_TEXT_BASE 0x00000000
> >> #define CONFIG_SPL_DATA_BASE 0xA0000000
> >> #define CONFIG_SPL_STACK     0xA0001000
> >>
> >> Signed-off-by: Kuo-Jung Su <dantesu@gmail.com>
> >> Cc: Albert Aribaud <albert.u.boot@aribaud.net>
> >
> > Can you provide an example user of this functionality?  Thanks.
> >
> > --
> > Tom
> 
> If you're looking for a real device, unfortunately there is no such
> device right now,
> it's a shiny new design which just came out last week.
> 
> If you're looking for a way for verification:
> 
> 1. A real device with a NOR flash for ROM emulation. (e.g., Faraday A369 EVB)
> 
> 2. A virtual device emulator. (e.g., Qemu)
> 
>    This is the best option for you, the Qemu model for Faraday A369 is
> available at my github account.
>    Please use the command bellow to grab the source tree if necessary.
> 
>    $ git clone -b qemu-1.5.1 https://github.com/dantesu1218/qemu.git
>    $ cd qemu
>    $ ./configure --target-list=arm-softmmu
>    $ make
> 
>    The example IPL code for the up-coming Faraday A369 U-boot is also available:
> 
>    $ git clone -b u-boot-2014.01 https://github.com/dantesu1218/u-boot.git
>    $ cd u-boot
>    $ make a369evb_ipl_config
>    $ make
> 
>    You could also directly grab  the pre-built binaries for quick verification.
> 
>    $ wget https://drive.google.com/file/d/0BwfiewvSmUgAMlBnUkZQb3FMVkE/edit?usp=sharing
>    $ tar xf u-boot-a369-ipl.tar.bz2
>    $ cd u-boot-a369-ipl
>    $ make

What I'm asking for, is can you upstream the a369evb board?  In the
README in board/... you should just document how to use it via QEMU.
Thanks!

-- 
Tom
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[U-Boot] [PATCH] arm: add IPL support

[Kuo-Jung Su]

2013/12/10 Tom Rini <trini@ti.com>:
> On Mon, Dec 09, 2013 at 04:07:29PM +0800, Kuo-Jung Su wrote:
>> 2013/12/6 Tom Rini <trini@ti.com>:
>> > On Wed, Dec 04, 2013 at 11:50:48AM +0800, Kuo-Jung Su wrote:
>> >
>> >> Initial Program Loader (IPL) usually runs with .text and .rodata
>> >> in ROM, while .data and .bss reside in RAM.
>> >>
>> >> This patch uses the AT keyword to specify load address,
>> >> and a small code snippet in crt0.S to restore .data section
>> >> at runtime.
>> >>
>> >> Example usage:
>> >> Assume the target device has a 4KB ROM at 0x00000000 and a
>> >> 4KB SRAM at 0xA0000000, the IPL/SPL config could be:
>> >>
>> >> #define CONFIG_SPL_MAX_SIZE  0x1000 /* text + data, no bss */
>> >> #define CONFIG_SPL_TEXT_BASE 0x00000000
>> >> #define CONFIG_SPL_DATA_BASE 0xA0000000
>> >> #define CONFIG_SPL_STACK     0xA0001000
>> >>
>> >> Signed-off-by: Kuo-Jung Su <dantesu@gmail.com>
>> >> Cc: Albert Aribaud <albert.u.boot@aribaud.net>
>> >
>> > Can you provide an example user of this functionality?  Thanks.
>> >
>> > --
>> > Tom
>>
>> If you're looking for a real device, unfortunately there is no such
>> device right now,
>> it's a shiny new design which just came out last week.
>>
>> If you're looking for a way for verification:
>>
>> 1. A real device with a NOR flash for ROM emulation. (e.g., Faraday A369 EVB)
>>
>> 2. A virtual device emulator. (e.g., Qemu)
>>
>>    This is the best option for you, the Qemu model for Faraday A369 is
>> available at my github account.
>>    Please use the command bellow to grab the source tree if necessary.
>>
>>    $ git clone -b qemu-1.5.1 https://github.com/dantesu1218/qemu.git
>>    $ cd qemu
>>    $ ./configure --target-list=arm-softmmu
>>    $ make
>>
>>    The example IPL code for the up-coming Faraday A369 U-boot is also available:
>>
>>    $ git clone -b u-boot-2014.01 https://github.com/dantesu1218/u-boot.git
>>    $ cd u-boot
>>    $ make a369evb_ipl_config
>>    $ make
>>
>>    You could also directly grab  the pre-built binaries for quick verification.
>>
>>    $ wget https://drive.google.com/file/d/0BwfiewvSmUgAMlBnUkZQb3FMVkE/edit?usp=sharing
>>    $ tar xf u-boot-a369-ipl.tar.bz2
>>    $ cd u-boot-a369-ipl
>>    $ make
>
> What I'm asking for, is can you upstream the a369evb board?  In the
> README in board/... you should just document how to use it via QEMU.
> Thanks!
>

Got it, thanks.

I will make it a part of Faraday A36x patch series, and resend it later.

-- 
Best wishes,
Kuo-Jung Su