diff mbox series

[U-Boot,v2] arm, imx6: add support for SD/MMC Manufacture Mode

Message ID 20180622051603.9592-1-jay.d.carlson@gmail.com
State Rejected
Delegated to: Stefano Babic
Headers show
Series [U-Boot,v2] arm, imx6: add support for SD/MMC Manufacture Mode | expand

Commit Message

Jay Carlson June 22, 2018, 5:16 a.m. UTC
This patch adds support for booting blank i.MX6 devices in SD/MMC Manufacture
Mode: a fallback mode which the boot ROM enters when no fuses or boot mode 
pins have been set, the USB serial downloader connection is inactive, and there
is an SD card inserted into uSDHC1. The i.MX7 and i.MX8, which both have 
a Boot_SW_Info data structure which can be parsed to determine boot source, is
unaffected by this patch.

Signed-off-by: Jay Carlson <jay.d.carlson@gmail.com>
---
 arch/arm/mach-imx/spl.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Stefano Babic July 23, 2018, 8:46 a.m. UTC | #1
Hi Jay,

On 22/06/2018 07:16, Jay Carlson wrote:
> This patch adds support for booting blank i.MX6 devices in SD/MMC Manufacture
> Mode: a fallback mode which the boot ROM enters when no fuses or boot mode 
> pins have been set, the USB serial downloader connection is inactive, and there
> is an SD card inserted into uSDHC1. The i.MX7 and i.MX8, which both have 
> a Boot_SW_Info data structure which can be parsed to determine boot source, is
> unaffected by this patch.
> 
> Signed-off-by: Jay Carlson <jay.d.carlson@gmail.com>
> ---
>  arch/arm/mach-imx/spl.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/arch/arm/mach-imx/spl.c b/arch/arm/mach-imx/spl.c
> index a20b30d154..8ecae8605c 100644
> --- a/arch/arm/mach-imx/spl.c
> +++ b/arch/arm/mach-imx/spl.c
> @@ -43,6 +43,16 @@ u32 spl_boot_device(void)
>  	 */
>  	if (is_usbotg_phy_active())
>  		return BOOT_DEVICE_BOARD;
> +	
> +	/**
> +	 * To support SD/MMC Manufacture Mode, we check that BOOT_MODE == 0
> +	 * and that BT_FUSE_SEL == 0. If this was disabled via
> +	 * blowing DISABLE_SDMMC_MFG, or if SDMMC MFG mode failed,
> +	 * we would be in USB download mode, which the previous line would 
> +	 * have detected.
> +	 */
> +	if (((bmode >> 24) & 0x03) == 0x00 && (bmode >> 4) == 0x00)
> +		return BOOT_DEVICE_MMC1;
>  
>  	/* BOOT_CFG1[7:4] - see IMX6DQRM Table 8-8 */
>  	switch ((reg & IMX6_BMODE_MASK) >> IMX6_BMODE_SHIFT) {
> 

This looks to me a fix for a custom board, but it does not seem that can
be applied general for all devices. I understand that this works in your
use case, where you have soldered eMMC and in factory you install the
software via SD card. But this is one use case.

Your change goes into general code (mach-imx/spl.c), and then it can
breaks many projects. You coul write your board_boot_order() in your
boot code to set the order of the device to be booted.

Best regards,
Stefano Babic
diff mbox series

Patch

diff --git a/arch/arm/mach-imx/spl.c b/arch/arm/mach-imx/spl.c
index a20b30d154..8ecae8605c 100644
--- a/arch/arm/mach-imx/spl.c
+++ b/arch/arm/mach-imx/spl.c
@@ -43,6 +43,16 @@  u32 spl_boot_device(void)
 	 */
 	if (is_usbotg_phy_active())
 		return BOOT_DEVICE_BOARD;
+	
+	/**
+	 * To support SD/MMC Manufacture Mode, we check that BOOT_MODE == 0
+	 * and that BT_FUSE_SEL == 0. If this was disabled via
+	 * blowing DISABLE_SDMMC_MFG, or if SDMMC MFG mode failed,
+	 * we would be in USB download mode, which the previous line would 
+	 * have detected.
+	 */
+	if (((bmode >> 24) & 0x03) == 0x00 && (bmode >> 4) == 0x00)
+		return BOOT_DEVICE_MMC1;
 
 	/* BOOT_CFG1[7:4] - see IMX6DQRM Table 8-8 */
 	switch ((reg & IMX6_BMODE_MASK) >> IMX6_BMODE_SHIFT) {