[U-Boot] SAMA5D2 xplained SD/eMMC boot

[Yang, Wenyou]

Hi Marek,

> -----Original Message-----
> From: Marek Vasut [mailto:marex at denx.de]
> Sent: 2016年4月21日 10:59
> To: Yang, Wenyou <Wenyou.Yang at atmel.com>
> Cc: u-boot at lists.denx.de
> Subject: Re: SAMA5D2 xplained SD/eMMC boot
> 
> On 04/21/2016 04:46 AM, Yang, Wenyou wrote:
> > Hi,
> 
> Hi!
> 
> [...]
> pile of unnecessary email headers redacted.
> [...]
> 
> >>>>>>>> Hi!
> >>>>>>>>
> >>>>>>>> I've been playing around with latest mainline u-boot on sama5d2
> >>>>>>>> xplained ultra. I noticed that if I want to boot the board from
> >>>>>>>> SD card (SDHCI1), the board will indeed load the SPL from it,
> >>>>>>>> but SPL will try to load u-boot.img from eMMC
> >>>>>>>> (SDHCI0) and fail, as my eMMC is blank.
> >>>>>>>
> >>>>>>> Yes, there is some issue to load u-boot.img. I found there is
> >>>>>>> something to do on
> >>>>>> sdhci.c.
> >>>>>>>
> >>>>>>> You can try this branch, it should works.
> >>>>>>>
> >>>>>>> https://github.com/linux4sam/u-boot-at91/commits/u-boot-2016.03-
> >>>>>>> at
> >>>>>>> 91
> >>>>>>
> >>>>>> I am not interested in using non-mainline stuff. Do you have any
> >>>>>> particular patch/commit which I can refer to ? I do not think
> >>>>>> this has anything to do with sdhci.c driver at all, it has to do
> >>>>>> with detecting the boot device from which SPL was started and
> >>>>>> loading u-boot.img from the same boot device instead of always using
> SDHCI0.
> >>>>>
> >>>>> I will test the mainline code. I will let you know when I get something.
> >>>>
> >>>> OK.
> >>>>
> >>>> Does the SoC have any sort of register which lists the current boot device ?
> >>>
> >>> In this SoC, there is not register to list the current boot device.
> >>
> >> And thus, it is not possible to detect at runtime from which device
> >> the SoC booted and thus load u-boot.img from the same device. Correct ?
> >
> > Yes,
> 
> Ha, thanks for confirming.

Sorry, can I correct what I said yesterday? There is a register to list the boot information exported by ROMCode.

The boot information is stored in R4 register when the ROMCode jumps to the bootstrap. 

Here is the contents definitions R4 on the SAMA5D2 (improved compared to old MPUs to take care of IOSet features).

/* bootFrom ID Definitions */
#define BOOT_FROM_KEY             	(0xBAu << 24)

#define BOOT_FROM_SPI               	(0x0u << 0)
#define BOOT_FROM_MCI               	(0x1u << 0)
#define BOOT_FROM_SMC               	(0x2u << 0)
#define BOOT_FROM_TWI               	(0x3u << 0)
#define BOOT_FROM_QSPI             	(0x4u << 0)

/* ID number of the IP from the data sheet */
#define BOOT_FROM_ID0               (0x0u << 4)
#define BOOT_FROM_ID1               (0x1u << 4)
#define BOOT_FROM_ID2               (0x2u << 4)
#define BOOT_FROM_ID3               (0x3u << 4)
#define BOOT_FROM_ID4               (0x4u << 4)

#define BOOT_FROM_ID_Pos            	4
#define BOOT_FROM_ID_Msk            	(0xfu << BOOT_FROM_ID_Pos)
#define BOOT_FROM_ID(value)         	((BOOT_FROM_ID_Msk & ((value) << BOOT_FROM_ID_Pos)))

#define BOOT_FROM_TYPE_SD_OR_AT25   	(0x0u << 8)
#define BOOT_FROM_TYPE_MMC_OR_AT45  (0x1u << 8)
#define BOOT_FROM_TYPE_EMMC         	(0x2u << 8)

/* QSPI serial flashes */
#define BOOT_FROM_TYPE_SPANSION     	(0x0u << 8)
#define BOOT_FROM_TYPE_MICRON       	(0x1u << 8)
#define BOOT_FROM_TYPE_MACRONIX     	(0x2u << 8)

/* Chip Select or (MCI) Slot identifier used in code by the IP. */
#define BOOT_FROM_CS0               (0x0u << 12) // Slot A
#define BOOT_FROM_CS1               (0x1u << 12) // Slot B
#define BOOT_FROM_CS2               (0x2u << 12) // Slot C
#define BOOT_FROM_CS3               (0x3u << 12) // Slot D
#define BOOT_FROM_CS4               (0x4u << 12)

#define BOOT_FROM_CS_Pos            12
#define BOOT_FROM_CS_Msk            (0xfu << BOOT_FROM_CS_Pos)
#define BOOT_FROM_CS(value)         ((BOOT_FROM_CS_Msk & ((value) << BOOT_FROM_CS_Pos)))

#define BOOT_FROM_IOSET_Pos         16
#define BOOT_FROM_IOSET_Msk         (0x3u << BOOT_FROM_IOSET_Pos)
#define BOOT_FROM_IOSET(value)       ((BOOT_FROM_IOSET_Msk & ((value) << BOOT_FROM_IOSET_Pos)))>>


> [...]
> 
> --
> Best regards,
> Marek Vasut

Sorry for incorrect information before.


Best Regards,
Wenyou Yang