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 <[email protected]> Signed-off-by: Simon Glass <[email protected]> Signed-off-by: Vivek Gautam <[email protected]> --- 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 + /* MMC SPL */ #define CONFIG_SPL #define COPY_BL2_FNPTR_ADDR 0x02020030 -- 1.7.6.5 _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
