[U-Boot] [RFC PATCH 0/3] sunxi: extend SPL header to propagate DRAM size

[U-Boot] [RFC PATCH 0/3] sunxi: extend SPL header to propagate DRAM size

[Andre Przywara]

This series tries to solve three issues we currently have on
Allwinner boards:
- The DRAM sizing routine can only cope with power-of-two sized DRAM.
- The DRAM sizing routine steps through all DRAM, possibly hitting secure
  memory.
- The SPL header versioning is quite strict and tends to break every time
  we need to update it.

So I thought about introducing something along the lines of semantic
versioning[1], where we can add backwards-compatible changes to the SPL
header without breaking every tool. This is introduced in the first patch.
The second patch does some refactoring, so that the third patch can use
the newly gained freedom to store the DRAM size. The SPL knows the DRAM
size very well, so we store this in the SPL header, so that U-Boot proper
can pick it up from there. This saves the call to get_ram_size() with
its deficiencies.
More information in the respective commit messages.

I understand that this versioning solution is not fully future-proof, but
we have only one byte for the version, and I just wanted to start
discussion on this.
There is a corresponding patch for sunxi-tools as well I am posting shortly.

[1] https://semver.org

Cheers,
Andre.

Andre Przywara (3):
  sunxi: Extend SPL header versioning
  sunxi: board.c: refactor SPL header checks
  sunxi: store DRAM size in SPL header

 arch/arm/include/asm/arch-sunxi/spl.h | 22 ++++++++----
 board/sunxi/board.c                   | 66 ++++++++++++++++++++++++++++-------
 2 files changed, 70 insertions(+), 18 deletions(-)

-- 
2.14.1

[U-Boot] [RFC PATCH 1/3] sunxi: Extend SPL header versioning

[Andre Przywara]

On Allwinner SoCs we use some free bytes at the beginning of the SPL image
to store various information. We have a version byte to allow updates,
but changing this always requires all tools to be updated as well.

Introduce the concept of semantic versioning [1] to the SPL header:
The major part of the version number only changes on incompatible
updates, a minor number bump indicates backward compatibility.
This patch just documents the major/minor split, adds some comments
to the header file and uses the versioning information for the existing
users.

[1] https://semver.org

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 arch/arm/include/asm/arch-sunxi/spl.h | 19 ++++++++++++++-----
 board/sunxi/board.c                   |  4 ++--
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/arch/arm/include/asm/arch-sunxi/spl.h b/arch/arm/include/asm/arch-sunxi/spl.h
index 4277d836e5..7cf89c8db2 100644
--- a/arch/arm/include/asm/arch-sunxi/spl.h
+++ b/arch/arm/include/asm/arch-sunxi/spl.h
@@ -9,7 +9,16 @@
 
 #define BOOT0_MAGIC		"eGON.BT0"
 #define SPL_SIGNATURE		"SPL" /* marks "sunxi" SPL header */
-#define SPL_HEADER_VERSION	2
+#define SPL_MAJOR_BITS		3
+#define SPL_MINOR_BITS		5
+#define SPL_VERSION(maj, min)						\
+	((((maj) & ((1U << SPL_MAJOR_BITS) - 1)) << SPL_MINOR_BITS) | \
+	((min) & ((1U << SPL_MINOR_BITS) - 1)))
+
+#define SPL_HEADER_VERSION	SPL_VERSION(0, 2)
+
+#define SPL_ENV_HEADER_VERSION	SPL_VERSION(0, 1)
+#define SPL_DT_HEADER_VERSION	SPL_VERSION(0, 2)
 
 #ifdef CONFIG_SUNXI_HIGH_SRAM
 #define SPL_ADDR		0x10000
@@ -49,14 +58,14 @@ struct boot_file_head {
 		uint32_t pub_head_size;
 		uint8_t spl_signature[4];
 	};
-	uint32_t fel_script_address;
+	uint32_t fel_script_address;	/* since v0.1, set by sunxi-fel */
 	/*
 	 * If the fel_uEnv_length member below is set to a non-zero value,
 	 * it specifies the size (byte count) of data@fel_script_address.
 	 * At the same time this indicates that the data is in uEnv.txt
 	 * compatible format, ready to be imported via "env import -t".
 	 */
-	uint32_t fel_uEnv_length;
+	uint32_t fel_uEnv_length;	/* since v0.1, set by sunxi-fel */
 	/*
 	 * Offset of an ASCIIZ string (relative to the SPL header), which
 	 * contains the default device tree name (CONFIG_DEFAULT_DEVICE_TREE).
@@ -64,11 +73,11 @@ struct boot_file_head {
 	 * by flash programming tools for providing nice informative messages
 	 * to the users.
 	 */
-	uint32_t dt_name_offset;
+	uint32_t dt_name_offset;	/* since v0.2, set by mksunxiboot */
 	uint32_t reserved1;
 	uint32_t boot_media;		/* written here by the boot ROM */
 	/* A padding area (may be used for storing text strings) */
-	uint32_t string_pool[13];
+	uint32_t string_pool[13];	/* since v0.2, filled by mksunxiboot */
 	/* The header must be a multiple of 32 bytes (for VBAR alignment) */
 };
 
diff --git a/board/sunxi/board.c b/board/sunxi/board.c
index 3d364c6db5..a105d0a5ab 100644
--- a/board/sunxi/board.c
+++ b/board/sunxi/board.c
@@ -631,9 +631,9 @@ static void parse_spl_header(const uint32_t spl_addr)
 		return; /* signature mismatch, no usable header */
 
 	uint8_t spl_header_version = spl->spl_signature[3];
-	if (spl_header_version != SPL_HEADER_VERSION) {
+	if (spl_header_version < SPL_ENV_HEADER_VERSION) {
 		printf("sunxi SPL version mismatch: expected %u, got %u\n",
-		       SPL_HEADER_VERSION, spl_header_version);
+		       SPL_ENV_HEADER_VERSION, spl_header_version);
 		return;
 	}
 	if (!spl->fel_script_address)
-- 
2.14.1

[U-Boot] [RFC PATCH 2/3] sunxi: board.c: refactor SPL header checks

[Andre Przywara]

So far we have two users which want to look at the SPL header. We will
get more in the future.
Refactor the existing SPL header checks into a common function, to
simplify reusing the code.
Now that this is easy, add proper version checks to the DT name parsing.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 board/sunxi/board.c | 41 ++++++++++++++++++++++++++++++-----------
 1 file changed, 30 insertions(+), 11 deletions(-)

diff --git a/board/sunxi/board.c b/board/sunxi/board.c
index a105d0a5ab..0bb7b023ed 100644
--- a/board/sunxi/board.c
+++ b/board/sunxi/board.c
@@ -253,6 +253,30 @@ int board_init(void)
 	return soft_i2c_board_init();
 }
 
+/*
+ * On older SoCs the SPL is actually at address zero, so using NULL as
+ * an error value does not work.
+ */
+#define INVALID_SPL_HEADER ((void *)~0UL)
+
+static struct boot_file_head * get_spl_header(uint8_t req_version)
+{
+	struct boot_file_head *spl = (void *)(ulong)SPL_ADDR;
+	uint8_t spl_header_version = spl->spl_signature[3];
+
+	/* Is there really the SPL header (still) there? */
+	if (memcmp(spl->spl_signature, SPL_SIGNATURE, 3) != 0)
+		return INVALID_SPL_HEADER;
+
+	if (spl_header_version < req_version) {
+		printf("sunxi SPL version mismatch: expected %u, got %u\n",
+		       req_version, spl_header_version);
+		return INVALID_SPL_HEADER;
+	}
+
+	return spl;
+}
+
 int dram_init(void)
 {
 	gd->ram_size = get_ram_size((long *)PHYS_SDRAM_0, PHYS_SDRAM_0_SIZE);
@@ -626,16 +650,11 @@ void get_board_serial(struct tag_serialnr *serialnr)
  */
 static void parse_spl_header(const uint32_t spl_addr)
 {
-	struct boot_file_head *spl = (void *)(ulong)spl_addr;
-	if (memcmp(spl->spl_signature, SPL_SIGNATURE, 3) != 0)
-		return; /* signature mismatch, no usable header */
+	struct boot_file_head *spl = get_spl_header(SPL_ENV_HEADER_VERSION);
 
-	uint8_t spl_header_version = spl->spl_signature[3];
-	if (spl_header_version < SPL_ENV_HEADER_VERSION) {
-		printf("sunxi SPL version mismatch: expected %u, got %u\n",
-		       SPL_ENV_HEADER_VERSION, spl_header_version);
+	if (spl == INVALID_SPL_HEADER)
 		return;
-	}
+
 	if (!spl->fel_script_address)
 		return;
 
@@ -777,11 +796,11 @@ int ft_board_setup(void *blob, bd_t *bd)
 #ifdef CONFIG_SPL_LOAD_FIT
 int board_fit_config_name_match(const char *name)
 {
-	struct boot_file_head *spl = (void *)(ulong)SPL_ADDR;
-	const char *cmp_str = (void *)(ulong)SPL_ADDR;
+	struct boot_file_head *spl = get_spl_header(SPL_DT_HEADER_VERSION);
+	const char *cmp_str = (const char *)spl;
 
 	/* Check if there is a DT name stored in the SPL header and use that. */
-	if (spl->dt_name_offset) {
+	if (spl != INVALID_SPL_HEADER && spl->dt_name_offset) {
 		cmp_str += spl->dt_name_offset;
 	} else {
 #ifdef CONFIG_DEFAULT_DEVICE_TREE
-- 
2.14.1

[U-Boot] [RFC PATCH 3/3] sunxi: store DRAM size in SPL header

[Andre Przywara]

At the moment we rely on the infamous get_ram_size() function to learn
the actual DRAM size in U-Boot proper. This function has two issues:
1) It only works if the DRAM size is a power of two. We start to see
boards which have 3GB of (usable) DRAM, so this does not fit anymore.
2) As U-Boot has no notion of reserved memory so far, it will happily
ride through the DRAM, possibly stepping on secure-only memory. This
could be a region of DRAM reserved for OP-TEE or some other secure
payload, for instance. It will most likely crash in that case.

As the SPL DRAM init routine has very accurate knowledge of the actual
DRAM size, lets propagate this wisdom to U-Boot proper.
We re-purpose a currently reserved word in our SPL header for that.
The SPL itself stores the detected DRAM size there, and bumps the SPL
header version number in that case. U-Boot proper checks for a valid
SPL header and a high enough version number, then uses the DRAM size
from there. If the SPL header field is not sufficient, we fall back to
the old DRAM scanning routine.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 arch/arm/include/asm/arch-sunxi/spl.h |  3 ++-
 board/sunxi/board.c                   | 25 ++++++++++++++++++++++++-
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/arch/arm/include/asm/arch-sunxi/spl.h b/arch/arm/include/asm/arch-sunxi/spl.h
index 7cf89c8db2..c5386b3f24 100644
--- a/arch/arm/include/asm/arch-sunxi/spl.h
+++ b/arch/arm/include/asm/arch-sunxi/spl.h
@@ -19,6 +19,7 @@
 
 #define SPL_ENV_HEADER_VERSION	SPL_VERSION(0, 1)
 #define SPL_DT_HEADER_VERSION	SPL_VERSION(0, 2)
+#define SPL_DRAM_HEADER_VERSION	SPL_VERSION(0, 3)
 
 #ifdef CONFIG_SUNXI_HIGH_SRAM
 #define SPL_ADDR		0x10000
@@ -74,7 +75,7 @@ struct boot_file_head {
 	 * to the users.
 	 */
 	uint32_t dt_name_offset;	/* since v0.2, set by mksunxiboot */
-	uint32_t reserved1;
+	uint32_t dram_size;		/* in MiB, since v0.3, set by SPL */
 	uint32_t boot_media;		/* written here by the boot ROM */
 	/* A padding area (may be used for storing text strings) */
 	uint32_t string_pool[13];	/* since v0.2, filled by mksunxiboot */
diff --git a/board/sunxi/board.c b/board/sunxi/board.c
index 0bb7b023ed..2b92d33cf1 100644
--- a/board/sunxi/board.c
+++ b/board/sunxi/board.c
@@ -279,7 +279,13 @@ static struct boot_file_head * get_spl_header(uint8_t req_version)
 
 int dram_init(void)
 {
-	gd->ram_size = get_ram_size((long *)PHYS_SDRAM_0, PHYS_SDRAM_0_SIZE);
+	struct boot_file_head *spl = get_spl_header(SPL_DRAM_HEADER_VERSION);
+
+	if (spl == INVALID_SPL_HEADER)
+		gd->ram_size = get_ram_size((long *)PHYS_SDRAM_0,
+					    PHYS_SDRAM_0_SIZE);
+	else
+		gd->ram_size = (phys_addr_t)spl->dram_size << 20;
 
 	return 0;
 }
@@ -537,6 +543,21 @@ int board_mmc_init(bd_t *bis)
 #endif
 
 #ifdef CONFIG_SPL_BUILD
+
+static void sunxi_spl_store_dram_size(phys_addr_t dram_size)
+{
+	struct boot_file_head *spl = get_spl_header(SPL_DT_HEADER_VERSION);
+
+	if (spl == INVALID_SPL_HEADER)
+		return;
+
+	/* Promote the header version for U-Boot proper, if needed. */
+	if (spl->spl_signature[3] < SPL_DRAM_HEADER_VERSION)
+		spl->spl_signature[3] = SPL_DRAM_HEADER_VERSION;
+
+	spl->dram_size = dram_size >> 20;
+}
+
 void sunxi_board_init(void)
 {
 	int power_failed = 0;
@@ -605,6 +626,8 @@ void sunxi_board_init(void)
 	if (!gd->ram_size)
 		hang();
 
+	sunxi_spl_store_dram_size(gd->ram_size);
+
 	/*
 	 * Only clock up the CPU to full speed if we are reasonably
 	 * assured it's being powered with suitable core voltage
-- 
2.14.1

[U-Boot] [RFC PATCH 0/3] sunxi: extend SPL header to propagate DRAM size

[Maxime Ripard]

On Thu, May 17, 2018 at 09:16:58AM +0100, Andre Przywara wrote:
> This series tries to solve three issues we currently have on
> Allwinner boards:
> - The DRAM sizing routine can only cope with power-of-two sized DRAM.
> - The DRAM sizing routine steps through all DRAM, possibly hitting secure
>   memory.
> - The SPL header versioning is quite strict and tends to break every time
>   we need to update it.
> 
> So I thought about introducing something along the lines of semantic
> versioning[1], where we can add backwards-compatible changes to the SPL
> header without breaking every tool. This is introduced in the first patch.
> The second patch does some refactoring, so that the third patch can use
> the newly gained freedom to store the DRAM size. The SPL knows the DRAM
> size very well, so we store this in the SPL header, so that U-Boot proper
> can pick it up from there. This saves the call to get_ram_size() with
> its deficiencies.
> More information in the respective commit messages.
> 
> I understand that this versioning solution is not fully future-proof, but
> we have only one byte for the version, and I just wanted to start
> discussion on this.
> There is a corresponding patch for sunxi-tools as well I am posting shortly.
> 
> [1] https://semver.org

I'm not sure I have a lot of comments to make, this looks sane to me :)

Maxime

-- 
Maxime Ripard, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com
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[U-Boot] [RFC PATCH 0/3] sunxi: extend SPL header to propagate DRAM size

[Icenowy Zheng]

于 2018年5月17日 GMT+08:00 下午4:16:58, Andre Przywara <andre.przywara@arm.com> 写到:
>This series tries to solve three issues we currently have on
>Allwinner boards:
>- The DRAM sizing routine can only cope with power-of-two sized DRAM.
>- The DRAM sizing routine steps through all DRAM, possibly hitting
>secure
>  memory.
>- The SPL header versioning is quite strict and tends to break every
>time
>  we need to update it.
>
>So I thought about introducing something along the lines of semantic
>versioning[1], where we can add backwards-compatible changes to the SPL
>header without breaking every tool. This is introduced in the first

How to define the "backwards-compatible"?

Should it have a standard? (e.g. tools have no change needed
and U-Boot will have fallback code)

>patch.
>The second patch does some refactoring, so that the third patch can use
>the newly gained freedom to store the DRAM size. The SPL knows the DRAM
>size very well, so we store this in the SPL header, so that U-Boot
>proper
>can pick it up from there. This saves the call to get_ram_size() with
>its deficiencies.
>More information in the respective commit messages.
>
>I understand that this versioning solution is not fully future-proof,
>but
>we have only one byte for the version, and I just wanted to start
>discussion on this.
>There is a corresponding patch for sunxi-tools as well I am posting
>shortly.
>
>[1] https://semver.org
>
>Cheers,
>Andre.
>
>Andre Przywara (3):
>  sunxi: Extend SPL header versioning
>  sunxi: board.c: refactor SPL header checks
>  sunxi: store DRAM size in SPL header
>
> arch/arm/include/asm/arch-sunxi/spl.h | 22 ++++++++----
>board/sunxi/board.c                   | 66
>++++++++++++++++++++++++++++-------
> 2 files changed, 70 insertions(+), 18 deletions(-)

[U-Boot] [RFC PATCH 0/3] sunxi: extend SPL header to propagate DRAM size

[Andre Przywara]

Hi,

On 17/05/18 09:35, Icenowy Zheng wrote:
> 
> 
> 于 2018年5月17日 GMT+08:00 下午4:16:58, Andre Przywara <andre.przywara@arm.com> 写到:
>> This series tries to solve three issues we currently have on
>> Allwinner boards:
>> - The DRAM sizing routine can only cope with power-of-two sized DRAM.
>> - The DRAM sizing routine steps through all DRAM, possibly hitting
>> secure
>>  memory.
>> - The SPL header versioning is quite strict and tends to break every
>> time
>>  we need to update it.
>>
>> So I thought about introducing something along the lines of semantic
>> versioning[1], where we can add backwards-compatible changes to the SPL
>> header without breaking every tool. This is introduced in the first
> 
> How to define the "backwards-compatible"?

Yeah, that's a good question I was hoping to get some input on.
Ideally backwards-compatible means that older tools can cope with the
new feature, so for instance anyone not knowing about the DRAM size
introduced in v3 would still be happy (either ignoring it or not using it).

Now what's special about our situation is that we have several agents
dealing with the SPL header:
- The BootROM puts the boot source in there. That's probably a
no-brainer for now, but later BootROMs might behave differently. We
might need to update the major version when they do so without changing
the magic number.
- mksunxiboot creates the header and puts the version number in there.
It populates the DT name field since v2. I kept it at v2 for now, since
it's only the SPL populating the v3 DRAM size field.
- sunxi-fel reads the header and adds the FEL script address in there,
requiring at least v1. In the moment it insists on the version number
being at most 2, which my sunxi-tools patch tries to fix.
- Now the SPL and U-Boot use a field themselves (DRAM size), and I
bumped the version if needed.

> Should it have a standard? (e.g. tools have no change needed
> and U-Boot will have fallback code)

Yeah, that sounds like some sensible definition.

The only problem I see is what happens when we need a v4 feature for
mksunxiboot. This would lead U-Boot proper to believe the DRAM size
field is valid, even though the SPL might not have populated it. Not
sure we care about it, or if there is a better solution (feature bits?).

Cheers,
Andre.

>> patch.
>> The second patch does some refactoring, so that the third patch can use
>> the newly gained freedom to store the DRAM size. The SPL knows the DRAM
>> size very well, so we store this in the SPL header, so that U-Boot
>> proper
>> can pick it up from there. This saves the call to get_ram_size() with
>> its deficiencies.
>> More information in the respective commit messages.
>>
>> I understand that this versioning solution is not fully future-proof,
>> but
>> we have only one byte for the version, and I just wanted to start
>> discussion on this.
>> There is a corresponding patch for sunxi-tools as well I am posting
>> shortly.
>>
>> [1] https://semver.org
>>
>> Cheers,
>> Andre.
>>
>> Andre Przywara (3):
>>  sunxi: Extend SPL header versioning
>>  sunxi: board.c: refactor SPL header checks
>>  sunxi: store DRAM size in SPL header
>>
>> arch/arm/include/asm/arch-sunxi/spl.h | 22 ++++++++----
>> board/sunxi/board.c                   | 66
>> ++++++++++++++++++++++++++++-------
>> 2 files changed, 70 insertions(+), 18 deletions(-)

[U-Boot] [RFC PATCH 1/3] sunxi: Extend SPL header versioning

[Siarhei Siamashka]

On Thu, 17 May 2018 09:16:59 +0100
Andre Przywara <andre.przywara@arm.com> wrote:

> On Allwinner SoCs we use some free bytes at the beginning of the SPL image
> to store various information. We have a version byte to allow updates,
> but changing this always requires all tools to be updated as well.

The tools do not need to be updated together with U-Boot even now.

U-Boot may freely increment the SPL version number as long as the new
header is a superset of the old one.

> Introduce the concept of semantic versioning [1] to the SPL header:
> The major part of the version number only changes on incompatible
> updates, a minor number bump indicates backward compatibility.
> This patch just documents the major/minor split, adds some comments
> to the header file and uses the versioning information for the existing
> users.
> 
> [1] https://semver.org

So basically you are implementing the versioning scheme that I proposed
back in 2015:
    https://lists.denx.de/pipermail/u-boot/2015-September/228727.html

Hans de Goede thought that the major/minor versioning was too complex
and unnecessary (if I remember correctly, we had several discussion
threads which concluded in the same way), so we did not implement it
explicitly back then. But a potential non-compatible SPL header upgrade
still could be handled, albeit less gracefully:

    Yes, we can also always change the SPL header signature in the case
    of introducing incompatible changes. But the down side is that the
    "fel" tool would treat this situation as "unknown bootloader"
    instead of "incompatible U-Boot".

> Signed-off-by: Andre Przywara <andre.przywara@arm.com>

In general, improvements in this area are welcome. Just some
comments below.

> ---
>  arch/arm/include/asm/arch-sunxi/spl.h | 19 ++++++++++++++-----
>  board/sunxi/board.c                   |  4 ++--
>  2 files changed, 16 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/arm/include/asm/arch-sunxi/spl.h b/arch/arm/include/asm/arch-sunxi/spl.h
> index 4277d836e5..7cf89c8db2 100644
> --- a/arch/arm/include/asm/arch-sunxi/spl.h
> +++ b/arch/arm/include/asm/arch-sunxi/spl.h
> @@ -9,7 +9,16 @@
>  
>  #define BOOT0_MAGIC		"eGON.BT0"
>  #define SPL_SIGNATURE		"SPL" /* marks "sunxi" SPL header */
> -#define SPL_HEADER_VERSION	2
> +#define SPL_MAJOR_BITS		3
> +#define SPL_MINOR_BITS		5
> +#define SPL_VERSION(maj, min)						\
> +	((((maj) & ((1U << SPL_MAJOR_BITS) - 1)) << SPL_MINOR_BITS) | \
> +	((min) & ((1U << SPL_MINOR_BITS) - 1)))
> +
> +#define SPL_HEADER_VERSION	SPL_VERSION(0, 2)
> +
> +#define SPL_ENV_HEADER_VERSION	SPL_VERSION(0, 1)
> +#define SPL_DT_HEADER_VERSION	SPL_VERSION(0, 2)
>  
>  #ifdef CONFIG_SUNXI_HIGH_SRAM
>  #define SPL_ADDR		0x10000
> @@ -49,14 +58,14 @@ struct boot_file_head {
>  		uint32_t pub_head_size;
>  		uint8_t spl_signature[4];
>  	};
> -	uint32_t fel_script_address;
> +	uint32_t fel_script_address;	/* since v0.1, set by sunxi-fel */

Thanks, it's nice to have these comments about the versions where these
features were introduced.

>  	/*
>  	 * If the fel_uEnv_length member below is set to a non-zero value,
>  	 * it specifies the size (byte count) of data at fel_script_address.
>  	 * At the same time this indicates that the data is in uEnv.txt
>  	 * compatible format, ready to be imported via "env import -t".
>  	 */
> -	uint32_t fel_uEnv_length;
> +	uint32_t fel_uEnv_length;	/* since v0.1, set by sunxi-fel */
>  	/*
>  	 * Offset of an ASCIIZ string (relative to the SPL header), which
>  	 * contains the default device tree name (CONFIG_DEFAULT_DEVICE_TREE).
> @@ -64,11 +73,11 @@ struct boot_file_head {
>  	 * by flash programming tools for providing nice informative messages
>  	 * to the users.
>  	 */
> -	uint32_t dt_name_offset;
> +	uint32_t dt_name_offset;	/* since v0.2, set by mksunxiboot */
>  	uint32_t reserved1;
>  	uint32_t boot_media;		/* written here by the boot ROM */
>  	/* A padding area (may be used for storing text strings) */
> -	uint32_t string_pool[13];
> +	uint32_t string_pool[13];	/* since v0.2, filled by mksunxiboot */

The 0.2 version of the SPL header does not specify the exact
format of this 'string_pool' padding area. So I think that this
comment is unnecessary.

In principle, the device tree name string can be stored even
somewhere in the const data section of the SPL binary and
referenced from the SPL header. Not that it makes any sense to
do this, but it is technically possible.

>  	/* The header must be a multiple of 32 bytes (for VBAR alignment) */
>  };
>  
> diff --git a/board/sunxi/board.c b/board/sunxi/board.c
> index 3d364c6db5..a105d0a5ab 100644
> --- a/board/sunxi/board.c
> +++ b/board/sunxi/board.c
> @@ -631,9 +631,9 @@ static void parse_spl_header(const uint32_t spl_addr)
>  		return; /* signature mismatch, no usable header */
>  
>  	uint8_t spl_header_version = spl->spl_signature[3];
> -	if (spl_header_version != SPL_HEADER_VERSION) {
> +	if (spl_header_version < SPL_ENV_HEADER_VERSION) {

We have already discussed this particular part of code earlier:
    https://lists.denx.de/pipermail/u-boot/2015-September/227999.html

Essentially, unless we have a real use case for mixing the SPL and the
main U-Boot parts built from different U-Boot versions, I don't see any
purpose for doing anything other than just exact version check here.

If this particular check fails (the SPL part does not match the main
U-Boot part), then something is already very wrong.

>  		printf("sunxi SPL version mismatch: expected %u, got %u\n",
> -		       SPL_HEADER_VERSION, spl_header_version);
> +		       SPL_ENV_HEADER_VERSION, spl_header_version);
>  		return;
>  	}
>  	if (!spl->fel_script_address)

-- 
Best regards,
Siarhei Siamashka

[U-Boot] [RFC PATCH 1/3] sunxi: Extend SPL header versioning

[Icenowy Zheng]

于 2018年5月17日 GMT+08:00 下午7:05:15, Siarhei Siamashka <siarhei.siamashka@gmail.com> 写到:
>On Thu, 17 May 2018 09:16:59 +0100
>Andre Przywara <andre.przywara@arm.com> wrote:
>
>> On Allwinner SoCs we use some free bytes at the beginning of the SPL
>image
>> to store various information. We have a version byte to allow
>updates,
>> but changing this always requires all tools to be updated as well.
>
>The tools do not need to be updated together with U-Boot even now.
>
>U-Boot may freely increment the SPL version number as long as the new
>header is a superset of the old one.

But now sunxi-fel will work when SPL ver not recognized.

>
>> Introduce the concept of semantic versioning [1] to the SPL header:
>> The major part of the version number only changes on incompatible
>> updates, a minor number bump indicates backward compatibility.
>> This patch just documents the major/minor split, adds some comments
>> to the header file and uses the versioning information for the
>existing
>> users.
>> 
>> [1] https://semver.org
>
>So basically you are implementing the versioning scheme that I proposed
>back in 2015:
>    https://lists.denx.de/pipermail/u-boot/2015-September/228727.html
>
>Hans de Goede thought that the major/minor versioning was too complex
>and unnecessary (if I remember correctly, we had several discussion
>threads which concluded in the same way), so we did not implement it
>explicitly back then. But a potential non-compatible SPL header upgrade
>still could be handled, albeit less gracefully:
>
>    Yes, we can also always change the SPL header signature in the case
>    of introducing incompatible changes. But the down side is that the
>    "fel" tool would treat this situation as "unknown bootloader"
>    instead of "incompatible U-Boot".
>
>> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
>
>In general, improvements in this area are welcome. Just some
>comments below.
>
>> ---
>>  arch/arm/include/asm/arch-sunxi/spl.h | 19 ++++++++++++++-----
>>  board/sunxi/board.c                   |  4 ++--
>>  2 files changed, 16 insertions(+), 7 deletions(-)
>> 
>> diff --git a/arch/arm/include/asm/arch-sunxi/spl.h
>b/arch/arm/include/asm/arch-sunxi/spl.h
>> index 4277d836e5..7cf89c8db2 100644
>> --- a/arch/arm/include/asm/arch-sunxi/spl.h
>> +++ b/arch/arm/include/asm/arch-sunxi/spl.h
>> @@ -9,7 +9,16 @@
>>  
>>  #define BOOT0_MAGIC		"eGON.BT0"
>>  #define SPL_SIGNATURE		"SPL" /* marks "sunxi" SPL header */
>> -#define SPL_HEADER_VERSION	2
>> +#define SPL_MAJOR_BITS		3
>> +#define SPL_MINOR_BITS		5
>> +#define SPL_VERSION(maj, min)						\
>> +	((((maj) & ((1U << SPL_MAJOR_BITS) - 1)) << SPL_MINOR_BITS) | \
>> +	((min) & ((1U << SPL_MINOR_BITS) - 1)))
>> +
>> +#define SPL_HEADER_VERSION	SPL_VERSION(0, 2)
>> +
>> +#define SPL_ENV_HEADER_VERSION	SPL_VERSION(0, 1)
>> +#define SPL_DT_HEADER_VERSION	SPL_VERSION(0, 2)
>>  
>>  #ifdef CONFIG_SUNXI_HIGH_SRAM
>>  #define SPL_ADDR		0x10000
>> @@ -49,14 +58,14 @@ struct boot_file_head {
>>  		uint32_t pub_head_size;
>>  		uint8_t spl_signature[4];
>>  	};
>> -	uint32_t fel_script_address;
>> +	uint32_t fel_script_address;	/* since v0.1, set by sunxi-fel */
>
>Thanks, it's nice to have these comments about the versions where these
>features were introduced.
>
>>  	/*
>>  	 * If the fel_uEnv_length member below is set to a non-zero value,
>>  	 * it specifies the size (byte count) of data at
>fel_script_address.
>>  	 * At the same time this indicates that the data is in uEnv.txt
>>  	 * compatible format, ready to be imported via "env import -t".
>>  	 */
>> -	uint32_t fel_uEnv_length;
>> +	uint32_t fel_uEnv_length;	/* since v0.1, set by sunxi-fel */
>>  	/*
>>  	 * Offset of an ASCIIZ string (relative to the SPL header), which
>>  	 * contains the default device tree name
>(CONFIG_DEFAULT_DEVICE_TREE).
>> @@ -64,11 +73,11 @@ struct boot_file_head {
>>  	 * by flash programming tools for providing nice informative
>messages
>>  	 * to the users.
>>  	 */
>> -	uint32_t dt_name_offset;
>> +	uint32_t dt_name_offset;	/* since v0.2, set by mksunxiboot */
>>  	uint32_t reserved1;
>>  	uint32_t boot_media;		/* written here by the boot ROM */
>>  	/* A padding area (may be used for storing text strings) */
>> -	uint32_t string_pool[13];
>> +	uint32_t string_pool[13];	/* since v0.2, filled by mksunxiboot */
>
>The 0.2 version of the SPL header does not specify the exact
>format of this 'string_pool' padding area. So I think that this
>comment is unnecessary.
>
>In principle, the device tree name string can be stored even
>somewhere in the const data section of the SPL binary and
>referenced from the SPL header. Not that it makes any sense to
>do this, but it is technically possible.
>
>>  	/* The header must be a multiple of 32 bytes (for VBAR alignment)
>*/
>>  };
>>  
>> diff --git a/board/sunxi/board.c b/board/sunxi/board.c
>> index 3d364c6db5..a105d0a5ab 100644
>> --- a/board/sunxi/board.c
>> +++ b/board/sunxi/board.c
>> @@ -631,9 +631,9 @@ static void parse_spl_header(const uint32_t
>spl_addr)
>>  		return; /* signature mismatch, no usable header */
>>  
>>  	uint8_t spl_header_version = spl->spl_signature[3];
>> -	if (spl_header_version != SPL_HEADER_VERSION) {
>> +	if (spl_header_version < SPL_ENV_HEADER_VERSION) {
>
>We have already discussed this particular part of code earlier:
>    https://lists.denx.de/pipermail/u-boot/2015-September/227999.html
>
>Essentially, unless we have a real use case for mixing the SPL and the
>main U-Boot parts built from different U-Boot versions, I don't see any
>purpose for doing anything other than just exact version check here.
>
>If this particular check fails (the SPL part does not match the main
>U-Boot part), then something is already very wrong.
>
>>  		printf("sunxi SPL version mismatch: expected %u, got %u\n",
>> -		       SPL_HEADER_VERSION, spl_header_version);
>> +		       SPL_ENV_HEADER_VERSION, spl_header_version);
>>  		return;
>>  	}
>>  	if (!spl->fel_script_address)

[U-Boot] [RFC PATCH 1/3] sunxi: Extend SPL header versioning

[Andre Przywara]

Hi,

On 17/05/18 12:05, Siarhei Siamashka wrote:
> On Thu, 17 May 2018 09:16:59 +0100
> Andre Przywara <andre.przywara@arm.com> wrote:
> 
>> On Allwinner SoCs we use some free bytes at the beginning of the SPL image
>> to store various information. We have a version byte to allow updates,
>> but changing this always requires all tools to be updated as well.
> 
> The tools do not need to be updated together with U-Boot even now.
> 
> U-Boot may freely increment the SPL version number as long as the new
> header is a superset of the old one.
> 
>> Introduce the concept of semantic versioning [1] to the SPL header:
>> The major part of the version number only changes on incompatible
>> updates, a minor number bump indicates backward compatibility.
>> This patch just documents the major/minor split, adds some comments
>> to the header file and uses the versioning information for the existing
>> users.
>>
>> [1] https://semver.org
> 
> So basically you are implementing the versioning scheme that I proposed
> back in 2015:
>     https://lists.denx.de/pipermail/u-boot/2015-September/228727.html

Ah, sorry, that predates my sunxi involvement ;-)

> Hans de Goede thought that the major/minor versioning was too complex
> and unnecessary (if I remember correctly, we had several discussion
> threads which concluded in the same way), so we did not implement it
> explicitly back then. But a potential non-compatible SPL header upgrade
> still could be handled, albeit less gracefully:
> 
>     Yes, we can also always change the SPL header signature in the case
>     of introducing incompatible changes. But the down side is that the
>     "fel" tool would treat this situation as "unknown bootloader"
>     instead of "incompatible U-Boot".
> 
>> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> 
> In general, improvements in this area are welcome. Just some
> comments below.
> 
>> ---
>>  arch/arm/include/asm/arch-sunxi/spl.h | 19 ++++++++++++++-----
>>  board/sunxi/board.c                   |  4 ++--
>>  2 files changed, 16 insertions(+), 7 deletions(-)
>>
>> diff --git a/arch/arm/include/asm/arch-sunxi/spl.h b/arch/arm/include/asm/arch-sunxi/spl.h
>> index 4277d836e5..7cf89c8db2 100644
>> --- a/arch/arm/include/asm/arch-sunxi/spl.h
>> +++ b/arch/arm/include/asm/arch-sunxi/spl.h
>> @@ -9,7 +9,16 @@
>>  
>>  #define BOOT0_MAGIC		"eGON.BT0"
>>  #define SPL_SIGNATURE		"SPL" /* marks "sunxi" SPL header */
>> -#define SPL_HEADER_VERSION	2
>> +#define SPL_MAJOR_BITS		3
>> +#define SPL_MINOR_BITS		5
>> +#define SPL_VERSION(maj, min)						\
>> +	((((maj) & ((1U << SPL_MAJOR_BITS) - 1)) << SPL_MINOR_BITS) | \
>> +	((min) & ((1U << SPL_MINOR_BITS) - 1)))
>> +
>> +#define SPL_HEADER_VERSION	SPL_VERSION(0, 2)
>> +
>> +#define SPL_ENV_HEADER_VERSION	SPL_VERSION(0, 1)
>> +#define SPL_DT_HEADER_VERSION	SPL_VERSION(0, 2)
>>  
>>  #ifdef CONFIG_SUNXI_HIGH_SRAM
>>  #define SPL_ADDR		0x10000
>> @@ -49,14 +58,14 @@ struct boot_file_head {
>>  		uint32_t pub_head_size;
>>  		uint8_t spl_signature[4];
>>  	};
>> -	uint32_t fel_script_address;
>> +	uint32_t fel_script_address;	/* since v0.1, set by sunxi-fel */
> 
> Thanks, it's nice to have these comments about the versions where these
> features were introduced.
> 
>>  	/*
>>  	 * If the fel_uEnv_length member below is set to a non-zero value,
>>  	 * it specifies the size (byte count) of data at fel_script_address.
>>  	 * At the same time this indicates that the data is in uEnv.txt
>>  	 * compatible format, ready to be imported via "env import -t".
>>  	 */
>> -	uint32_t fel_uEnv_length;
>> +	uint32_t fel_uEnv_length;	/* since v0.1, set by sunxi-fel */
>>  	/*
>>  	 * Offset of an ASCIIZ string (relative to the SPL header), which
>>  	 * contains the default device tree name (CONFIG_DEFAULT_DEVICE_TREE).
>> @@ -64,11 +73,11 @@ struct boot_file_head {
>>  	 * by flash programming tools for providing nice informative messages
>>  	 * to the users.
>>  	 */
>> -	uint32_t dt_name_offset;
>> +	uint32_t dt_name_offset;	/* since v0.2, set by mksunxiboot */
>>  	uint32_t reserved1;
>>  	uint32_t boot_media;		/* written here by the boot ROM */
>>  	/* A padding area (may be used for storing text strings) */
>> -	uint32_t string_pool[13];
>> +	uint32_t string_pool[13];	/* since v0.2, filled by mksunxiboot */
> 
> The 0.2 version of the SPL header does not specify the exact
> format of this 'string_pool' padding area. So I think that this
> comment is unnecessary.

Well, I understand that it *could* be everywhere, but I wanted to give a
heads up to the reader that the actual mksunxiboot implementation fills
that area, so it's not really vacant anymore. That may become of
importance if we need more fields.

> In principle, the device tree name string can be stored even
> somewhere in the const data section of the SPL binary and
> referenced from the SPL header. Not that it makes any sense to
> do this, but it is technically possible.
> 
>>  	/* The header must be a multiple of 32 bytes (for VBAR alignment) */
>>  };
>>  
>> diff --git a/board/sunxi/board.c b/board/sunxi/board.c
>> index 3d364c6db5..a105d0a5ab 100644
>> --- a/board/sunxi/board.c
>> +++ b/board/sunxi/board.c
>> @@ -631,9 +631,9 @@ static void parse_spl_header(const uint32_t spl_addr)
>>  		return; /* signature mismatch, no usable header */
>>  
>>  	uint8_t spl_header_version = spl->spl_signature[3];
>> -	if (spl_header_version != SPL_HEADER_VERSION) {
>> +	if (spl_header_version < SPL_ENV_HEADER_VERSION) {
> 
> We have already discussed this particular part of code earlier:
>     https://lists.denx.de/pipermail/u-boot/2015-September/227999.html
> 
> Essentially, unless we have a real use case for mixing the SPL and the
> main U-Boot parts built from different U-Boot versions, I don't see any
> purpose for doing anything other than just exact version check here.

For FEL booting we might trigger this. My personal use case is to have
FEL capable 32-bit SPL binaries for the ARMv8 SoCs lying around[2], and
using them with any version of U-Boot proper I want to test/debug.
So I hit this there. I see that this is quite a stretch, but this "<"
relation is what the code actually requires, especially now with the
semantic versioning, so I changed that.

Cheers,
Andre.

[2] https://github.com/apritzel/pine64/tree/master/binaries

> If this particular check fails (the SPL part does not match the main
> U-Boot part), then something is already very wrong.
> 
>>  		printf("sunxi SPL version mismatch: expected %u, got %u\n",
>> -		       SPL_HEADER_VERSION, spl_header_version);
>> +		       SPL_ENV_HEADER_VERSION, spl_header_version);
>>  		return;
>>  	}
>>  	if (!spl->fel_script_address)
> 

[U-Boot] [linux-sunxi] [RFC PATCH 0/3] sunxi: extend SPL header to propagate DRAM size

[Icenowy Zheng]

在 2018-05-17四的 09:16 +0100，Andre Przywara写道：
> This series tries to solve three issues we currently have on
> Allwinner boards:
> - The DRAM sizing routine can only cope with power-of-two sized DRAM.
> - The DRAM sizing routine steps through all DRAM, possibly hitting
> secure
>   memory.
> - The SPL header versioning is quite strict and tends to break every
> time
>   we need to update it.
> 
> So I thought about introducing something along the lines of semantic
> versioning[1], where we can add backwards-compatible changes to the
> SPL
> header without breaking every tool. This is introduced in the first
> patch.
> The second patch does some refactoring, so that the third patch can
> use
> the newly gained freedom to store the DRAM size. The SPL knows the
> DRAM
> size very well, so we store this in the SPL header, so that U-Boot
> proper
> can pick it up from there. This saves the call to get_ram_size() with
> its deficiencies.
> More information in the respective commit messages.
> 
> I understand that this versioning solution is not fully future-proof, 
> but
> we have only one byte for the version, and I just wanted to start
> discussion on this.
> There is a corresponding patch for sunxi-tools as well I am posting
> shortly.
> 
> [1] https://semver.org

Could I do some small reworks on this patchset and resend it?

We're now facing 3GiB Pine H64 releasing very soon.

> 
> Cheers,
> Andre.
> 
> Andre Przywara (3):
>   sunxi: Extend SPL header versioning
>   sunxi: board.c: refactor SPL header checks
>   sunxi: store DRAM size in SPL header
> 
>  arch/arm/include/asm/arch-sunxi/spl.h | 22 ++++++++----
>  board/sunxi/board.c                   | 66
> ++++++++++++++++++++++++++++-------
>  2 files changed, 70 insertions(+), 18 deletions(-)
> 
> -- 
> 2.14.1
> 

[U-Boot] [linux-sunxi] [RFC PATCH 0/3] sunxi: extend SPL header to propagate DRAM size

[André Przywara]

On 10/22/18 2:26 AM, Icenowy Zheng wrote:
> 在 2018-05-17四的 09:16 +0100，Andre Przywara写道：
>> This series tries to solve three issues we currently have on
>> Allwinner boards:
>> - The DRAM sizing routine can only cope with power-of-two sized DRAM.
>> - The DRAM sizing routine steps through all DRAM, possibly hitting
>> secure
>>   memory.
>> - The SPL header versioning is quite strict and tends to break every
>> time
>>   we need to update it.
>>
>> So I thought about introducing something along the lines of semantic
>> versioning[1], where we can add backwards-compatible changes to the
>> SPL
>> header without breaking every tool. This is introduced in the first
>> patch.
>> The second patch does some refactoring, so that the third patch can
>> use
>> the newly gained freedom to store the DRAM size. The SPL knows the
>> DRAM
>> size very well, so we store this in the SPL header, so that U-Boot
>> proper
>> can pick it up from there. This saves the call to get_ram_size() with
>> its deficiencies.
>> More information in the respective commit messages.
>>
>> I understand that this versioning solution is not fully future-proof, 
>> but
>> we have only one byte for the version, and I just wanted to start
>> discussion on this.
>> There is a corresponding patch for sunxi-tools as well I am posting
>> shortly.
>>
>> [1] https://semver.org
> 
> Could I do some small reworks on this patchset and resend it?

Yes, please. I was thinking about resending it as well.
The only issue is that we need the corresponding patch in sunxi-fel as
well, ideally before this one goes in.
But activity was somewhat low on sunxi-tools last time I mentioned this...

Cheers,
Andre.


> We're now facing 3GiB Pine H64 releasing very soon.

> 
>>
>> Cheers,
>> Andre.
>>
>> Andre Przywara (3):
>>   sunxi: Extend SPL header versioning
>>   sunxi: board.c: refactor SPL header checks
>>   sunxi: store DRAM size in SPL header
>>
>>  arch/arm/include/asm/arch-sunxi/spl.h | 22 ++++++++----
>>  board/sunxi/board.c                   | 66
>> ++++++++++++++++++++++++++++-------
>>  2 files changed, 70 insertions(+), 18 deletions(-)
>>
>> -- 
>> 2.14.1
>>
> 

[U-Boot] [linux-sunxi] [RFC PATCH 0/3] sunxi: extend SPL header to propagate DRAM size

[Icenowy Zheng]

在 2018-10-22一的 09:17 +0100，André Przywara写道：
> On 10/22/18 2:26 AM, Icenowy Zheng wrote:
> > 在 2018-05-17四的 09:16 +0100，Andre Przywara写道：
> > > This series tries to solve three issues we currently have on
> > > Allwinner boards:
> > > - The DRAM sizing routine can only cope with power-of-two sized
> > > DRAM.
> > > - The DRAM sizing routine steps through all DRAM, possibly
> > > hitting
> > > secure
> > >   memory.
> > > - The SPL header versioning is quite strict and tends to break
> > > every
> > > time
> > >   we need to update it.
> > > 
> > > So I thought about introducing something along the lines of
> > > semantic
> > > versioning[1], where we can add backwards-compatible changes to
> > > the
> > > SPL
> > > header without breaking every tool. This is introduced in the
> > > first
> > > patch.
> > > The second patch does some refactoring, so that the third patch
> > > can
> > > use
> > > the newly gained freedom to store the DRAM size. The SPL knows
> > > the
> > > DRAM
> > > size very well, so we store this in the SPL header, so that U-
> > > Boot
> > > proper
> > > can pick it up from there. This saves the call to get_ram_size()
> > > with
> > > its deficiencies.
> > > More information in the respective commit messages.
> > > 
> > > I understand that this versioning solution is not fully future-
> > > proof, 
> > > but
> > > we have only one byte for the version, and I just wanted to start
> > > discussion on this.
> > > There is a corresponding patch for sunxi-tools as well I am
> > > posting
> > > shortly.
> > > 
> > > [1] https://semver.org
> > 
> > Could I do some small reworks on this patchset and resend it?
> 
> Yes, please. I was thinking about resending it as well.
> The only issue is that we need the corresponding patch in sunxi-fel
> as
> well, ideally before this one goes in.

I think technically this patchset should be merged BEFORE the sunxi-fel 
patch, because there's no document, and U-Boot works as the document.

> But activity was somewhat low on sunxi-tools last time I mentioned
> this...
> 
> Cheers,
> Andre.
> 
> 
> > We're now facing 3GiB Pine H64 releasing very soon.
> > 
> > > 
> > > Cheers,
> > > Andre.
> > > 
> > > Andre Przywara (3):
> > >   sunxi: Extend SPL header versioning
> > >   sunxi: board.c: refactor SPL header checks
> > >   sunxi: store DRAM size in SPL header
> > > 
> > >  arch/arm/include/asm/arch-sunxi/spl.h | 22 ++++++++----
> > >  board/sunxi/board.c                   | 66
> > > ++++++++++++++++++++++++++++-------
> > >  2 files changed, 70 insertions(+), 18 deletions(-)
> > > 
> > > -- 
> > > 2.14.1
> > > 
> 
>