[U-Boot] [PATCH] Exynos5: Add support for USB download boot mode

[Simon Glass]

Hi,

On Mon, Jan 28, 2013 at 2:39 AM, Vivek Gautam <gautam.vivek at samsung.com> wrote:
> Exynos5250 supports secondary USB device boot mode. If the iROM fails
> to download u-boot from the primary boot device (such as SD or eMMC),
> it will try to retrieve from the secondary boot device (such as USB).
>
> Signed-off-by: Naveen Krishna Ch <ch.naveen at samsung.com>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> Signed-off-by: Vivek Gautam <gautam.vivek at samsung.com>

Acked-by: Simon Glass <sjg at chromium.org>

But please see comment below.

> ---
>
> NOTE:
>  - Based on 'master' branch of u-boot-samsung.
>  - Tested with smdk5250 for usb download mode.
>
>  board/samsung/smdk5250/spl_boot.c |   40 +++++++++++++++++++++++++++++++++++-
>  include/configs/exynos5250-dt.h   |    5 ++++
>  2 files changed, 43 insertions(+), 2 deletions(-)
>
> diff --git a/board/samsung/smdk5250/spl_boot.c b/board/samsung/smdk5250/spl_boot.c
> index d8f3c1e..c0bcf46 100644
> --- a/board/samsung/smdk5250/spl_boot.c
> +++ b/board/samsung/smdk5250/spl_boot.c
> @@ -32,6 +32,21 @@ enum boot_mode {
>  };
>
>         typedef u32 (*spi_copy_func_t)(u32 offset, u32 nblock, u32 dst);
> +       typedef u32 (*usb_copy_func_t)(void);
> +
> +/*
> + * Set/clear program flow prediction and return the previous state.
> + */
> +static int config_branch_prediction(int set_cr_z)
> +{
> +       unsigned int cr;
> +
> +       /* System Control Register: 11th bit Z Branch prediction enable */
> +       cr = get_cr();
> +       set_cr(set_cr_z ? cr | CR_Z : cr & ~CR_Z);
> +
> +       return cr & CR_Z;
> +}
>
>  /*
>  * Copy U-boot from mmc to RAM:
> @@ -41,10 +56,20 @@ enum boot_mode {
>  void copy_uboot_to_ram(void)
>  {
>         spi_copy_func_t spi_copy;
> -       enum boot_mode bootmode;
> +       usb_copy_func_t usb_copy;
> +
> +       int is_cr_z_set;
> +       unsigned int sec_boot_check;
> +       enum boot_mode bootmode = BOOT_MODE_OM;
>         u32 (*copy_bl2)(u32, u32, u32);
>
> -       bootmode = readl(EXYNOS5_POWER_BASE) & OM_STAT;
> +       /* Read iRAM location to check for secondary USB boot mode */
> +       sec_boot_check = readl(EXYNOS_IRAM_SECONDARY_BASE);
> +       if (sec_boot_check == EXYNOS_USB_SECONDARY_BOOT)
> +               bootmode = BOOT_MODE_USB;
> +
> +       if (bootmode == BOOT_MODE_OM)
> +               bootmode = readl(EXYNOS5_POWER_BASE) & OM_STAT;
>
>         switch (bootmode) {
>         case BOOT_MODE_SERIAL:
> @@ -57,6 +82,17 @@ void copy_uboot_to_ram(void)
>                 copy_bl2(BL2_START_OFFSET, BL2_SIZE_BLOC_COUNT,
>                                                 CONFIG_SYS_TEXT_BASE);
>                 break;
> +       case BOOT_MODE_USB:
> +               /*
> +                * iROM needs program flow prediction to be disabled
> +                * before copy from USB device to RAM
> +                */
> +               is_cr_z_set = config_branch_prediction(0);
> +               usb_copy = *(usb_copy_func_t *)
> +                               EXYNOS_COPY_USB_FNPTR_ADDR;
> +               usb_copy();
> +               config_branch_prediction(is_cr_z_set);
> +               break;
>         default:
>                 break;
>         }
> diff --git a/include/configs/exynos5250-dt.h b/include/configs/exynos5250-dt.h
> index cabd2f2..6728b0e 100644
> --- a/include/configs/exynos5250-dt.h
> +++ b/include/configs/exynos5250-dt.h
> @@ -123,6 +123,11 @@
>  #define CONFIG_USB_EHCI_EXYNOS
>  #define CONFIG_USB_STORAGE
>
> +/* USB boot mode */
> +#define EXYNOS_COPY_USB_FNPTR_ADDR     0x02020070
> +#define EXYNOS_USB_SECONDARY_BOOT      0xfeed0002
> +#define EXYNOS_IRAM_SECONDARY_BASE     0x02020018


What happened to the function pointer table patch?

> +
>  /* MMC SPL */
>  #define CONFIG_SPL
>  #define COPY_BL2_FNPTR_ADDR    0x02020030
> --
> 1.7.6.5
>

Regards,
Simon