[U-Boot,v3,2/3] sunxi/spl: Detect at runtime where from SPL was read

Make possible using single `u-boot-sunxi-with-spl.bin` binary for both NAND
memory and SD card. Detection where SPL was read from is implemented in
`spl_boot_device`.

V2:
- Move signature verification to helper function
- Avoid unnecessary condition nesting

V3:
- Further simplification of conditions
- Move reassigning mmc block.dev numbers from `board_mmc_init` to
  `spl_boot_device`
- If signature wasn't found on mmc0 and SPL_NAND_SUPPORT isn't enabled
  don't assume mmc2 is a valid boot device - check for egon signature
  first

Signed-off-by: Daniel Kochmański <dkochmanski@turtle-solutions.eu>
CC: Roy Spliet <r.spliet@ultimaker.com>
Cc: Ian Campbell <ijc@hellion.org.uk>
Cc: Hans De Goede <hdegoede@redhat.com>
---
 arch/arm/cpu/armv7/sunxi/board.c | 63 ++++++++++++++++++++++++++--------------
 1 file changed, 41 insertions(+), 22 deletions(-)

Hi,

On 29-05-15 16:55, Daniel Kochmański wrote:
> Make possible using single `u-boot-sunxi-with-spl.bin` binary for both NAND
> memory and SD card. Detection where SPL was read from is implemented in
> `spl_boot_device`.
>
> V2:
> - Move signature verification to helper function
> - Avoid unnecessary condition nesting
>
> V3:
> - Further simplification of conditions
> - Move reassigning mmc block.dev numbers from `board_mmc_init` to
>    `spl_boot_device`
> - If signature wasn't found on mmc0 and SPL_NAND_SUPPORT isn't enabled
>    don't assume mmc2 is a valid boot device - check for egon signature
>    first
>
> Signed-off-by: Daniel Kochmański <dkochmanski@turtle-solutions.eu>
> CC: Roy Spliet <r.spliet@ultimaker.com>
> Cc: Ian Campbell <ijc@hellion.org.uk>
> Cc: Hans De Goede <hdegoede@redhat.com>

Thanks, pushed with a few small coding style fixes (braces placement) to
u-boot-sunxi/next for merging into v2015.10 .

Regards,

Hans


> ---
>   arch/arm/cpu/armv7/sunxi/board.c | 63 ++++++++++++++++++++++++++--------------
>   1 file changed, 41 insertions(+), 22 deletions(-)
>
> diff --git a/arch/arm/cpu/armv7/sunxi/board.c b/arch/arm/cpu/armv7/sunxi/board.c
> index a82c8b9..c06922c 100644
> --- a/arch/arm/cpu/armv7/sunxi/board.c
> +++ b/arch/arm/cpu/armv7/sunxi/board.c
> @@ -11,6 +11,7 @@
>    */
>
>   #include <common.h>
> +#include <mmc.h>
>   #include <i2c.h>
>   #include <serial.h>
>   #ifdef CONFIG_SPL_BUILD
> @@ -22,6 +23,7 @@
>   #include <asm/arch/gpio.h>
>   #include <asm/arch/sys_proto.h>
>   #include <asm/arch/timer.h>
> +#include <asm/arch/mmc.h>
>
>   #include <linux/compiler.h>
>
> @@ -117,26 +119,18 @@ void s_init(void)
>   }
>
>   #ifdef CONFIG_SPL_BUILD
> +DECLARE_GLOBAL_DATA_PTR;
> +
>   /* The sunxi internal brom will try to loader external bootloader
>    * from mmc0, nand flash, mmc2.
> - *
> - * Unfortunately we can't check how SPL was loaded so assume it's
> - * always the first SD/MMC controller, unless it was explicitly
> - * stated that SPL is on nand flash.
>    */
>   u32 spl_boot_device(void)
>   {
> -#if defined(CONFIG_SPL_NAND_SUPPORT)
> +	struct mmc *mmc0, *mmc1;
>   	/*
> -	 * This is compile time configuration informing SPL, that it
> -	 * was loaded from nand flash.
> -	 */
> -	return BOOT_DEVICE_NAND;
> -#else
> -	/*
> -	 * When booting from the SD card, the "eGON.BT0" signature is expected
> -	 * to be found in memory at the address 0x0004 (see the "mksunxiboot"
> -	 * tool, which generates this header).
> +	 * When booting from the SD card or NAND memory, the "eGON.BT0"
> +	 * signature is expected to be found in memory at the address 0x0004
> +	 * (see the "mksunxiboot" tool, which generates this header).
>   	 *
>   	 * When booting in the FEL mode over USB, this signature is patched in
>   	 * memory and replaced with something else by the 'fel' tool. This other
> @@ -144,16 +138,41 @@ u32 spl_boot_device(void)
>   	 * valid bootable SD card image (because the BROM would refuse to
>   	 * execute the SPL in this case).
>   	 *
> -	 * This branch is just making a decision at runtime whether to load
> -	 * the main u-boot binary from the SD card (if the "eGON.BT0" signature
> -	 * is found) or return to the FEL code in the BROM to wait and receive
> -	 * the main u-boot binary over USB.
> +	 * This checks for the signature and if it is not found returns to
> +	 * the FEL code in the BROM to wait and receive the main u-boot
> +	 * binary over USB. If it is found, it determines where SPL was
> +	 * read from.
>   	 */
> -	if (readl(4) == 0x4E4F4765 && readl(8) == 0x3054422E) /* eGON.BT0 */
> -		return BOOT_DEVICE_MMC1;
> -	else
> +	if (readl(4) != 0x4E4F4765 || readl(8) != 0x3054422E) /* eGON.BT0 */
>   		return BOOT_DEVICE_BOARD;
> -#endif
> +
> +	/* The BROM will try to boot from mmc0 first, so try that first. */
> +	mmc_initialize(gd->bd);
> +	mmc0 = find_mmc_device(0);
> +	if (sunxi_mmc_has_egon_boot_signature(mmc0))
> +		return BOOT_DEVICE_MMC1;
> +
> +	/* Fallback to booting NAND if enabled. */
> +	if (IS_ENABLED(CONFIG_SPL_NAND_SUPPORT))
> +		return BOOT_DEVICE_NAND;
> +
> +	if (IS_ENABLED(CONFIG_MMC_SUNXI_SLOT_EXTRA) &&
> +	    CONFIG_MMC_SUNXI_SLOT_EXTRA == 2)
> +	{
> +		mmc1 = find_mmc_device(1);
> +		if (sunxi_mmc_has_egon_boot_signature(mmc1))
> +		{
> +			/* spl_mmc.c: spl_mmc_load_image() is hard-coded to
> +			 * use find_mmc_device(0), no matter what we
> +			 * return. Swap mmc0 and mmc2 to make this work. */
> +			mmc0->block_dev.dev = 1;
> +			mmc1->block_dev.dev = 0;
> +			return BOOT_DEVICE_MMC2
> +		}
> +	}
> +
> +	panic("Could not determine boot source\n");
> +	return -1;		/* Never reached */
>   }
>
>   /* No confirmation data available in SPL yet. Hardcode bootmode */
>