[PATCH 1/3] ARM: i.MX8M: remove unutilized start parameter to i.MX8M load functions

[PATCH 1/3] ARM: i.MX8M: remove unutilized start parameter to i.MX8M load functions

[Ahmad Fatoum]

We have two kinds of xload functions for i.MX: _start_image loads and
starts the image and _load_image takes a parameter on whether to start
the image after loading. All users of _load_image pass false as argument
for the start parameter and this is unlikely to change, because we need
to do other things before starting the image:

  - BL31: Install ARM Trusted Firmware
  - BL32: Optionally, extract OP-TEE from external firmware
  - BL33: Optionally, verify barebox proper when secure booting

_start_image doesn't concern itself with this:

  - BL31: We don't use TF-A on 32-bit i.MX systems and if barebox is secure
    monitor, it's installed in barebox proper
  - BL32: OP-TEE is shipped inside PBL or loaded by bootm on 32-bit i.MX
  - BL33: barebox is loaded directly to SDRAM after it was setup by DCD
          and is thus verified by bootrom as a whole. Chainloading
	  manually is not mixed with secure boot

For that reason, let's drop the start parameter to try to reduce
the complexity of the chainloading code a bit.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 arch/arm/mach-imx/atf.c        | 14 +++++++-------
 arch/arm/mach-imx/xload-qspi.c | 24 +++++++++++-------------
 drivers/mci/imx-esdhc-pbl.c    | 24 +++++++++++-------------
 include/mach/imx/romapi.h      |  1 +
 include/mach/imx/xload.h       | 14 ++++++++------
 5 files changed, 38 insertions(+), 39 deletions(-)

diff --git a/arch/arm/mach-imx/atf.c b/arch/arm/mach-imx/atf.c
index e1a89ef543cd..f9baad862dc7 100644
--- a/arch/arm/mach-imx/atf.c
+++ b/arch/arm/mach-imx/atf.c
@@ -65,7 +65,7 @@ void imx8mm_load_bl33(void *bl33)
 	imx8mm_get_boot_source(&src, &instance);
 	switch (src) {
 	case BOOTSOURCE_MMC:
-		imx8m_esdhc_load_image(instance, false);
+		imx8m_esdhc_load_image(instance);
 		break;
 	case BOOTSOURCE_SERIAL:
 		if (!IS_ENABLED(CONFIG_USB_GADGET_DRIVER_ARC_PBL)) {
@@ -98,7 +98,7 @@ void imx8mm_load_bl33(void *bl33)
 
 		break;
 	case BOOTSOURCE_SPI:
-		imx8mm_qspi_load_image(instance, false);
+		imx8mm_qspi_load_image(instance);
 		break;
 	default:
 		printf("Unsupported bootsource BOOTSOURCE_%d\n", src);
@@ -154,13 +154,13 @@ void imx8mp_load_bl33(void *bl33)
 	imx8mp_get_boot_source(&src, &instance);
 	switch (src) {
 	case BOOTSOURCE_MMC:
-		imx8mp_esdhc_load_image(instance, false);
+		imx8mp_esdhc_load_image(instance);
 		break;
 	case BOOTSOURCE_SERIAL:
 		imx8mp_romapi_load_image();
 		break;
 	case BOOTSOURCE_SPI:
-		imx8mp_qspi_load_image(instance, false);
+		imx8mp_qspi_load_image(instance);
 		break;
 	default:
 		printf("Unhandled bootsource BOOTSOURCE_%d\n", src);
@@ -218,13 +218,13 @@ void imx8mn_load_bl33(void *bl33)
 	imx8mn_get_boot_source(&src, &instance);
 	switch (src) {
 	case BOOTSOURCE_MMC:
-		imx8mn_esdhc_load_image(instance, false);
+		imx8mn_esdhc_load_image(instance);
 		break;
 	case BOOTSOURCE_SERIAL:
 		imx8mn_romapi_load_image();
 		break;
 	case BOOTSOURCE_SPI:
-		imx8mn_qspi_load_image(instance, false);
+		imx8mn_qspi_load_image(instance);
 		break;
 	default:
 		printf("Unhandled bootsource BOOTSOURCE_%d\n", src);
@@ -281,7 +281,7 @@ void imx8mq_load_bl33(void *bl33)
 	imx8mn_get_boot_source(&src, &instance);
 	switch (src) {
 	case BOOTSOURCE_MMC:
-		imx8m_esdhc_load_image(instance, false);
+		imx8m_esdhc_load_image(instance);
 		break;
 	default:
 		printf("Unhandled bootsource BOOTSOURCE_%d\n", src);
diff --git a/arch/arm/mach-imx/xload-qspi.c b/arch/arm/mach-imx/xload-qspi.c
index 6bf5bba5e69d..5089f20d627c 100644
--- a/arch/arm/mach-imx/xload-qspi.c
+++ b/arch/arm/mach-imx/xload-qspi.c
@@ -23,35 +23,33 @@ int imx8m_qspi_read(void *dest, size_t len, void *priv)
  * imx8mm_qspi_start_image - Load and optionally start an image from the
  *                           FlexSPI controller.
  * @instance: The FlexSPI controller instance
- * @start: Whether to directly start the loaded image
  *
  * This uses imx8m_qspi_load_image() to load an image from QSPI. It is assumed
- * that the image is the currently running barebox image (This information
- * is used to calculate the length of the image).
- * The image is started afterwards.
+ * that the image is the currently running barebox image.
+ * The image is not started afterwards.
  *
- * Return: If successful, this function does not return (if directly started)
- * or 0. A negative error code is returned when this function fails.
+ * Return: If image successfully loaded, returns 0.
+ * A negative error code is returned when this function fails.
  */
 static
-int imx8m_qspi_load_image(int instance, bool start, off_t offset, off_t ivt_offset)
+int imx8m_qspi_load_image(int instance, off_t offset, off_t ivt_offset)
 {
 	void __iomem *qspi_ahb = IOMEM(IMX8M_QSPI_MMAP);
 
 	return imx_load_image(MX8M_DDR_CSD1_BASE_ADDR, MX8M_ATF_BL33_BASE_ADDR,
-			      offset, ivt_offset, start, 0,
+			      offset, ivt_offset, false, 0,
 			      imx8m_qspi_read, qspi_ahb);
 }
 
-int imx8mm_qspi_load_image(int instance, bool start)
+int imx8mm_qspi_load_image(int instance)
 {
-	return imx8m_qspi_load_image(instance, start, 0, SZ_4K);
+	return imx8m_qspi_load_image(instance, 0, SZ_4K);
 }
 
-int imx8mn_qspi_load_image(int instance, bool start)
+int imx8mn_qspi_load_image(int instance)
 {
-	return imx8m_qspi_load_image(instance, start, SZ_4K, 0);
+	return imx8m_qspi_load_image(instance, SZ_4K, 0);
 }
 
-int imx8mp_qspi_load_image(int instance, bool start)
+int imx8mp_qspi_load_image(int instance)
 	__alias(imx8mn_qspi_load_image);
diff --git a/drivers/mci/imx-esdhc-pbl.c b/drivers/mci/imx-esdhc-pbl.c
index 2d071eaca88a..2cb703a0c552 100644
--- a/drivers/mci/imx-esdhc-pbl.c
+++ b/drivers/mci/imx-esdhc-pbl.c
@@ -242,17 +242,16 @@ int imx7_esdhc_start_image(int instance)
 /**
  * imx8m_esdhc_load_image - Load and optionally start an image from USDHC controller
  * @instance: The USDHC controller instance (0..2)
- * @start: Whether to directly start the loaded image
  *
  * This uses esdhc_start_image() to load an image from SD/MMC.  It is
  * assumed that the image is the currently running barebox image (This
  * information is used to calculate the length of the image). The
- * image is started afterwards.
+ * image is not started afterwards.
  *
- * Return: If successful, this function does not return (if directly started)
- * or 0. A negative error code is returned when this function fails.
+ * Return: If image successfully loaded, returns 0.
+ * A negative error code is returned when this function fails.
  */
-int imx8m_esdhc_load_image(int instance, bool start)
+int imx8m_esdhc_load_image(int instance)
 {
 	struct esdhc_soc_data data;
 	struct fsl_esdhc_host host = { 0 };
@@ -264,23 +263,22 @@ int imx8m_esdhc_load_image(int instance, bool start)
 
 	return esdhc_load_image(&host, MX8M_DDR_CSD1_BASE_ADDR,
 				MX8MQ_ATF_BL33_BASE_ADDR, SZ_32K, SZ_1K,
-				start);
+				false);
 }
 
 /**
  * imx8mp_esdhc_load_image - Load and optionally start an image from USDHC controller
  * @instance: The USDHC controller instance (0..2)
- * @start: Whether to directly start the loaded image
  *
  * This uses esdhc_start_image() to load an image from SD/MMC.  It is
  * assumed that the image is the currently running barebox image (This
  * information is used to calculate the length of the image). The
- * image is started afterwards.
+ * image is not started afterwards.
  *
- * Return: If successful, this function does not return (if directly started)
- * or 0. A negative error code is returned when this function fails.
+ * Return: If image successfully loaded, returns 0.
+ * A negative error code is returned when this function fails.
  */
-int imx8mp_esdhc_load_image(int instance, bool start)
+int imx8mp_esdhc_load_image(int instance)
 {
 	struct esdhc_soc_data data;
 	struct fsl_esdhc_host host = { 0 };
@@ -294,10 +292,10 @@ int imx8mp_esdhc_load_image(int instance, bool start)
 	offset = esdhc_bootpart_active(&host)? 0 : SZ_32K;
 
 	return esdhc_load_image(&host, MX8M_DDR_CSD1_BASE_ADDR,
-				MX8MQ_ATF_BL33_BASE_ADDR, offset, 0, start);
+				MX8MQ_ATF_BL33_BASE_ADDR, offset, 0, false);
 }
 
-int imx8mn_esdhc_load_image(int instance, bool start)
+int imx8mn_esdhc_load_image(int instance)
 	__alias(imx8mp_esdhc_load_image);
 #endif
 
diff --git a/include/mach/imx/romapi.h b/include/mach/imx/romapi.h
index 959d165a3323..05932fac88ce 100644
--- a/include/mach/imx/romapi.h
+++ b/include/mach/imx/romapi.h
@@ -35,6 +35,7 @@ enum boot_dev_type_e {
 
 #define ROM_API_OKAY		0xF0
 
+/* Below functions only load and don't start the image */
 int imx8mp_romapi_load_image(void);
 int imx8mn_romapi_load_image(void);
 int imx93_romapi_load_image(void);
diff --git a/include/mach/imx/xload.h b/include/mach/imx/xload.h
index 2c2d2fa3c52d..66219f9fef30 100644
--- a/include/mach/imx/xload.h
+++ b/include/mach/imx/xload.h
@@ -14,12 +14,14 @@ int imx6_esdhc_start_image(int instance);
 int imx6_nand_start_image(void);
 int imx7_esdhc_start_image(int instance);
 int imx7_nand_start_image(void);
-int imx8m_esdhc_load_image(int instance, bool start);
-int imx8mn_esdhc_load_image(int instance, bool start);
-int imx8mp_esdhc_load_image(int instance, bool start);
-int imx8mm_qspi_load_image(int instance, bool start);
-int imx8mn_qspi_load_image(int instance, bool start);
-int imx8mp_qspi_load_image(int instance, bool start);
+
+/* Below functions only load and don't start the image */
+int imx8m_esdhc_load_image(int instance);
+int imx8mn_esdhc_load_image(int instance);
+int imx8mp_esdhc_load_image(int instance);
+int imx8mm_qspi_load_image(int instance);
+int imx8mn_qspi_load_image(int instance);
+int imx8mp_qspi_load_image(int instance);
 
 void imx8mm_load_bl33(void *bl33);
 void imx8mn_load_bl33(void *bl33);
-- 
2.39.2

[PATCH 2/3] ARM: i.MX8M: return error if imx_load_image can't honour entry address

[Ahmad Fatoum]

On i.MX6 and 7, we call imx_load_image with start == true and address
equal to entry.

On i.MX8M, we call imx_load_image with start == false and address
unequal to entry.

imx_load_image interprets the address being unequal to entry as a
directive to move the image, so that the barebox entry point without
the i.MX header starts at exactly the entry address.

If we were to change this, say on an i.MX8MN, so address is equal
to entry, the system will no longer boot:

  - i.MX header is loaded to offset 0 from start of SDRAM (like on i.MX6/7)
  - barebox PBL entry point is loaded to offset 32K
  - imx8mX_load_bl33 will copy the running barebox PBL to offset 0

The result of this is that the TF-A will be able to return to barebox
(non-executable i.MX header overwritten with executable PBL), but
uncompressing barebox will fail (remainder of partially overwritten
PBL is interpreted as start of piggydata).

Add some documentation explaining this complexity, a hint on how we
could improve it and change the condition, so entry == address results
in an explicit warning message immediately.

Reported-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 arch/arm/mach-imx/xload-common.c | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-imx/xload-common.c b/arch/arm/mach-imx/xload-common.c
index 03eb2ef109e3..32f12cd7f574 100644
--- a/arch/arm/mach-imx/xload-common.c
+++ b/arch/arm/mach-imx/xload-common.c
@@ -78,6 +78,25 @@ imx_search_header(struct imx_flash_header_v2 **header_pointer,
 	return 0;
 }
 
+/**
+ * imx_load_image - Load i.MX barebox image from boot medium
+ * @address: Start address of SDRAM where barebox can be loaded into
+ * @entry: Address where barebox entry point should be placed.
+ *         This is ignored unless @start == false
+ * @offset: Start offset for i.MX header search
+ * @ivt_offset: offset between i.MX header and IVT
+ * @start: whether image should be started after loading
+ * @alignment: If nonzero, image size hardcoded in PBL will be aligned up
+ *             to this value
+ * @read: function pointer for reading from the beginning of the boot
+ *        medium onwards
+ * @priv: private data pointer passed to read function
+ *
+ * Return: A negative error code on failure.
+ * On success, if @start == true, the function will not return.
+ * If @start == false, the function will return 0 after placing the
+ * barebox entry point (without header) at @entry.
+ */
 int imx_load_image(ptrdiff_t address, ptrdiff_t entry, u32 offset,
 		   u32 ivt_offset, bool start, unsigned int alignment,
 		   int (*read)(void *dest, size_t len, void *priv),
@@ -102,7 +121,7 @@ int imx_load_image(ptrdiff_t address, ptrdiff_t entry, u32 offset,
 
 	ofs = offset + hdr->entry - hdr->boot_data.start;
 
-	if (entry != address) {
+	if (!start) {
 		/*
 		 * Passing entry different from address is interpreted
 		 * as a request to place the image such that its entry
@@ -129,6 +148,17 @@ int imx_load_image(ptrdiff_t address, ptrdiff_t entry, u32 offset,
 		buf = (void *)(entry - ofs);
 	}
 
+	/*
+	 * For SD/MMC High-Capacity support (> 2G), the offset for the block
+	 * read command is in blocks, not bytes. We don't have the information
+	 * whether we have a SDHC card or not, when we run here though, because
+	 * card setup was done by BootROM. To workaround this, we just read
+	 * from offset 0 as 0 blocks == 0 bytes.
+	 *
+	 * A result of this is that we will have to read the i.MX header and
+	 * padding in front of the binary first to arrive at the barebox entry
+	 * point.
+	 */
 	ret = read(buf, ofs + len, priv);
 	if (ret) {
 		pr_err("Loading image failed with %d\n", ret);
-- 
2.39.2

Re: [PATCH 2/3] ARM: i.MX8M: return error if imx_load_image can't honour entry address

[Marco Felsch]

Hi Ahmad,

On 24-01-15, Ahmad Fatoum wrote:
> On i.MX6 and 7, we call imx_load_image with start == true and address
> equal to entry.
> 
> On i.MX8M, we call imx_load_image with start == false and address
> unequal to entry.
> 
> imx_load_image interprets the address being unequal to entry as a
> directive to move the image, so that the barebox entry point without
> the i.MX header starts at exactly the entry address.
> 
> If we were to change this, say on an i.MX8MN, so address is equal
> to entry, the system will no longer boot:
> 
>   - i.MX header is loaded to offset 0 from start of SDRAM (like on i.MX6/7)
>   - barebox PBL entry point is loaded to offset 32K
>   - imx8mX_load_bl33 will copy the running barebox PBL to offset 0
> 
> The result of this is that the TF-A will be able to return to barebox
> (non-executable i.MX header overwritten with executable PBL), but
> uncompressing barebox will fail (remainder of partially overwritten
> PBL is interpreted as start of piggydata).

thanks for taking care of this.

> Add some documentation explaining this complexity, a hint on how we
> could improve it and change the condition, so entry == address results
> in an explicit warning message immediately.
> 
> Reported-by: Marco Felsch <m.felsch@pengutronix.de>
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
>  arch/arm/mach-imx/xload-common.c | 32 +++++++++++++++++++++++++++++++-
>  1 file changed, 31 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/mach-imx/xload-common.c b/arch/arm/mach-imx/xload-common.c
> index 03eb2ef109e3..32f12cd7f574 100644
> --- a/arch/arm/mach-imx/xload-common.c
> +++ b/arch/arm/mach-imx/xload-common.c
> @@ -78,6 +78,25 @@ imx_search_header(struct imx_flash_header_v2 **header_pointer,
>  	return 0;
>  }
>  
> +/**
> + * imx_load_image - Load i.MX barebox image from boot medium
> + * @address: Start address of SDRAM where barebox can be loaded into
> + * @entry: Address where barebox entry point should be placed.
> + *         This is ignored unless @start == false
> + * @offset: Start offset for i.MX header search
> + * @ivt_offset: offset between i.MX header and IVT
> + * @start: whether image should be started after loading
> + * @alignment: If nonzero, image size hardcoded in PBL will be aligned up
> + *             to this value
> + * @read: function pointer for reading from the beginning of the boot
> + *        medium onwards
> + * @priv: private data pointer passed to read function
> + *
> + * Return: A negative error code on failure.
> + * On success, if @start == true, the function will not return.
> + * If @start == false, the function will return 0 after placing the
> + * barebox entry point (without header) at @entry.
> + */
>  int imx_load_image(ptrdiff_t address, ptrdiff_t entry, u32 offset,
>  		   u32 ivt_offset, bool start, unsigned int alignment,
>  		   int (*read)(void *dest, size_t len, void *priv),
> @@ -102,7 +121,7 @@ int imx_load_image(ptrdiff_t address, ptrdiff_t entry, u32 offset,
>  
>  	ofs = offset + hdr->entry - hdr->boot_data.start;
>  
> -	if (entry != address) {
> +	if (!start) {
>  		/*
>  		 * Passing entry different from address is interpreted
>  		 * as a request to place the image such that its entry

Can you please adapt the comment here slightly to take the new (!start)
into account?

Regards,
  Marco


> @@ -129,6 +148,17 @@ int imx_load_image(ptrdiff_t address, ptrdiff_t entry, u32 offset,
>  		buf = (void *)(entry - ofs);
>  	}
>  
> +	/*
> +	 * For SD/MMC High-Capacity support (> 2G), the offset for the block
> +	 * read command is in blocks, not bytes. We don't have the information
> +	 * whether we have a SDHC card or not, when we run here though, because
> +	 * card setup was done by BootROM. To workaround this, we just read
> +	 * from offset 0 as 0 blocks == 0 bytes.
> +	 *
> +	 * A result of this is that we will have to read the i.MX header and
> +	 * padding in front of the binary first to arrive at the barebox entry
> +	 * point.
> +	 */
>  	ret = read(buf, ofs + len, priv);
>  	if (ret) {
>  		pr_err("Loading image failed with %d\n", ret);
> -- 
> 2.39.2
> 
> 

[PATCH 3/3] pbl: add COMPILE_TEST prompt for PBL_VERIFY_PIGGY

[Ahmad Fatoum]

PBL_VERIFY_PIGGY is selected by boards that require verification of
barebox proper, e.g. when secure booting. The option can also be useful
during debugging, just to verify that barebox proper was not corrupted,
therefore add a prompt when CONFIG_COMPILE_TEST=y.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 pbl/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pbl/Kconfig b/pbl/Kconfig
index 91970c19bc1e..f94791ff8a49 100644
--- a/pbl/Kconfig
+++ b/pbl/Kconfig
@@ -48,7 +48,7 @@ config PBL_RELOCATABLE
 
 config PBL_VERIFY_PIGGY
 	depends on ARM
-	bool
+	bool "Verify barebox proper hash before decompression" if COMPILE_TEST 
 
 config BOARD_GENERIC_DT
 	bool
-- 
2.39.2