[PATCH v2 2/4] mx6cuboxi: customize board_boot_order to access eMMC

[Baruch Siach]

Hi Walter,

On Thu, Mar 12, 2020 at 01:52:13PM -0300, Walter Lozano wrote:
> Hi Baruch,
> 
> Thanks for sharing.
> 
> On 12/3/20 02:02, Baruch Siach wrote:
> > Hi Walter,
> > 
> > On Wed, Mar 11 2020, Walter Lozano wrote:
> > > In SPL legacy code only one MMC device is created, based on BOOT_CFG
> > > register, which can be either SD or eMMC. In this context
> > > board_boot_order return always MMC1 when configure to boot from
> > > SD/eMMC. After switching to DM both SD and eMMC devices are created
> > > based on the information available on DT, but as board_boot_order
> > > only returns MMC1 is not possible to boot from eMMC.
> > > 
> > > This patch customizes board_boot_order taking into account BOOT_CFG
> > > register to point to correct MMC1 / MMC2 device. Additionally, handle
> > > IO mux for the desired boot device.
> > > 
> > > Signed-off-by: Walter Lozano <walter.lozano at collabora.com>
> > > ---
> > >   board/solidrun/mx6cuboxi/mx6cuboxi.c | 49 ++++++++++++++++++++++++++++
> > >   1 file changed, 49 insertions(+)
> > > 
> > > diff --git a/board/solidrun/mx6cuboxi/mx6cuboxi.c b/board/solidrun/mx6cuboxi/mx6cuboxi.c
> > > index 6a96f9ecdb..9bf3645f72 100644
> > > --- a/board/solidrun/mx6cuboxi/mx6cuboxi.c
> > > +++ b/board/solidrun/mx6cuboxi/mx6cuboxi.c
> > > @@ -435,6 +435,7 @@ int board_early_init_f(void)
> > >   #ifdef CONFIG_CMD_SATA
> > >   	setup_sata();
> > >   #endif
> > > +
> > This hunk should not be part of this commit.
> 
> Thanks for pointing to this silly hunk. I will prepare a V3.
> 
> > Looks good to me, otherwise.
> > 
> > I can't test at the moment. Have you tested boot from both SD card and eMMC?
> 
> Most of the work was done booting from SD. In order to test booting from
> eMMC, as I have some specific eFUSE configs, I tweaked board_boot_order to
> force booting from eMMC.

But that does not cover SPL boot from eMMC, right?

Anyway I tested your patches here on real hardware with unfused SOM and 
SD/eMMC boot select jumpers.

Tested-by: Baruch Siach <baruch at tkos.co.il>

> Regarding booting from SD/eMMC, I also wonder if having a list of boot
> devices would be useful, like
> 
> 	switch (boot_mode >> IMX6_BMODE_SHIFT) {
> 	case IMX6_BMODE_SD:
> 	case IMX6_BMODE_ESD:
> 	case IMX6_BMODE_MMC:
> 	case IMX6_BMODE_EMMC:
> 		SETUP_IOMUX_PADS(usdhc2_pads);
> 		SETUP_IOMUX_PADS(usdhc3_pads);
> 
> 		/*
> 		 * Upon reading BOOT_CFG register the following map is done:
> 		 * Bit 11 and 12 of BOOT_CFG register can determine the current
> 		 * mmc port
> 		 * 0x1                  SD2
> 		 * 0x2                  SD3
> 		 */
> 
> 		reg &= 0x3; /* Only care about bottom 2 bits */
> 		switch (reg) {
> 		case 1:
> 			spl_boot_list[0] = BOOT_DEVICE_MMC1;
> 			spl_boot_list[1] = BOOT_DEVICE_MMC2;
> 			break;
> 		case 2:
> 			spl_boot_list[0] = BOOT_DEVICE_MMC2;
> 			spl_boot_list[1] = BOOT_DEVICE_MMC1;
> 			break;
> 		}
> 		break;
> 
> What do you think?

This might cause surprising results when the U-Boot image on the SPL boot 
device is damaged for some reason. This kind of fallback device (other than 
USB boot) should not be enabled by default, in my opinion.

baruch

> > In the future, please keep i.MX maintainers (Stefano, Fabio) in Cc.
> 
> 
> Thanks for the advice. You are totally right.
> 
> Regards,
> 
> Walter
> 
> > Thanks,
> > baruch
> > 
> > >   	return 0;
> > >   }
> > > @@ -624,6 +625,54 @@ int board_fit_config_name_match(const char *name)
> > >   	return strcmp(name, tmp_name);
> > >   }
> > > +void board_boot_order(u32 *spl_boot_list)
> > > +{
> > > +	struct src *psrc = (struct src *)SRC_BASE_ADDR;
> > > +	unsigned int reg = readl(&psrc->sbmr1) >> 11;
> > > +	u32 boot_mode = imx6_src_get_boot_mode() & IMX6_BMODE_MASK;
> > > +	unsigned int bmode = readl(&src_base->sbmr2);
> > > +
> > > +	/* If bmode is serial or USB phy is active, return serial */
> > > +	if (((bmode >> 24) & 0x03) == 0x01 || is_usbotg_phy_active()) {
> > > +		spl_boot_list[0] = BOOT_DEVICE_BOARD;
> > > +		return;
> > > +	}
> > > +
> > > +	switch (boot_mode >> IMX6_BMODE_SHIFT) {
> > > +	case IMX6_BMODE_SD:
> > > +	case IMX6_BMODE_ESD:
> > > +	case IMX6_BMODE_MMC:
> > > +	case IMX6_BMODE_EMMC:
> > > +		/*
> > > +		 * Upon reading BOOT_CFG register the following map is done:
> > > +		 * Bit 11 and 12 of BOOT_CFG register can determine the current
> > > +		 * mmc port
> > > +		 * 0x1                  SD2
> > > +		 * 0x2                  SD3
> > > +		 */
> > > +
> > > +		reg &= 0x3; /* Only care about bottom 2 bits */
> > > +		switch (reg) {
> > > +		case 1:
> > > +			SETUP_IOMUX_PADS(usdhc2_pads);
> > > +			spl_boot_list[0] = BOOT_DEVICE_MMC1;
> > > +			break;
> > > +		case 2:
> > > +			SETUP_IOMUX_PADS(usdhc3_pads);
> > > +			spl_boot_list[0] = BOOT_DEVICE_MMC2;
> > > +			break;
> > > +		}
> > > +		break;
> > > +	default:
> > > +		/* By default use USB downloader */
> > > +		spl_boot_list[0] = BOOT_DEVICE_BOARD;
> > > +		break;
> > > +	}
> > > +
> > > +	/* As a last resort, use serial downloader */
> > > +	spl_boot_list[1] = BOOT_DEVICE_BOARD;
> > > +}
> > > +
> > >   #ifdef CONFIG_SPL_BUILD
> > >   #include <asm/arch/mx6-ddr.h>
> > >   static const struct mx6dq_iomux_ddr_regs mx6q_ddr_ioregs = {

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     http://baruch.siach.name/blog/                  ~. .~   Tk Open Systems
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