[eureka]

Originally Posted by adi23

I can't reflash my kernels back with fastboot becouse u-boot bist is missing (kernels and partitions are gone).

I've took a look at how fastboot is implemented in U-Boot. Unfortunately, I can't try validness of my research, as I have no access to serial console, but it should be enough to include following defines into include/configs/imx50_yoshi.h:

Spoiler:

#define CONFIG_MMC_MAX_TRANSFER_SIZE	(0xFFFF * 512)
#define CONFIG_USB_DEVICE		1
#define CONFIG_DRIVER_FSLUSB		1
#define CONFIG_GADGET_FASTBOOT		1

#define CONFIG_USBD_MANUFACTURER "Amazon"
#define CONFIG_USBD_PRODUCT_NAME "Kindle"

#define CONFIG_USBD_VENDORID			0x1949
#define CONFIG_USBD_PRODUCTID_FASTBOOT		0xd0d0
#define CONFIG_FASTBOOT_MAX_DOWNLOAD_LEN	((get_dram_size()) - (2*1024*1024) - (CONFIG_FASTBOOT_TEMP_BUFFER - CONFIG_SYS_SDRAM_BASE))
#define CONFIG_FASTBOOT_TEMP_BUFFER		0x7A000000

and then recompile U-Boot. Then new command shoud be accessible in U-Boot command line: fastboot.

Without fastboot u-boot.bin size is 62656 bytes, with fastboot size is 71580 bytes. So even with fastboot enabeld U-Boot should fit in OCRAM.

EDIT: oh I was deadly wrong about required defines as I've missed some of them. With additional defines size of u-boot.bin is more than 72kb, so it will not fit into OCRAM. If you're still interested:

Spoiler:

#define CONFIG_CMD_GADGET 1
#define CONFIG_USB_DEVICE               1
#define CONFIG_DRIVER_FSLUSB            1
#define CONFIG_GADGET_FASTBOOT          1
#define CONFIG_USBD_MANUFACTURER "Amazon"
#define CONFIG_USBD_PRODUCT_NAME "Kindle"
#define CONFIG_USBD_VENDORID                    0x1949
#define CONFIG_USBD_PRODUCTID_FASTBOOT          0xd0d0
#define CONFIG_MMC_MAX_TRANSFER_SIZE    (0xFFFF * 512)
#define CONFIG_FASTBOOT_MAX_DOWNLOAD_LEN        ((get_dram_size()) - (2*1024*1024) - (CONFIG_FASTBOOT_TEMP_BUFFER - CONFIG_SYS_SDRAM_BASE))
#define CONFIG_FASTBOOT_TEMP_BUFFER             0x7A000000
#define CRC32_BUFFER        0x02000000 + PHYS_SDRAM_1
#define CRC32_BUFFER_SIZE       0x00400000
#define CRC32_CHECK_UBOOT       0x00000010
#define CRC32_CHECK_UIMAGE      0x00000020
#define CRC32_CHECK_ROOTFS      0x00000040
#define CRC32_CHECK_MBR         0x00000080

Also change

#define CONFIG_POST         (CONFIG_SYS_POST_MEMORY | \
                             CONFIG_SYS_POST_FAIL)

to

#define CONFIG_POST         (CONFIG_SYS_POST_MMC_CRC32 | \
                             CONFIG_SYS_POST_MEMORY | \
                             CONFIG_SYS_POST_FAIL)