Using SABRE-SD u-boot on Sabre Lite for i.MX6
There are two lines of the evaluation boards for freescale i.mx6 - SABRE SD and Sabre Lite. The two boards have their own lines of u-boot. Some of the features available in the SABRE SD u-boot, for example SPL boot and the Falcon boot are not available in SABRE LITE board.
With some small modifications you can make the SABRE-SD u-boot to work on the Sabre-Lite board.
In include/configs/mx6sabresd.h
Change
#define CONFIG_MXC_UART_BASE UART1_BASE
to
#define CONFIG_MXC_UART_BASE UART2_BASE
Also,
#define CONSOLE_DEV "ttymxc0"
to
#define CONSOLE_DEV "ttymxc1
"
The SABRE SD board uses UART1 for the console message while the the Sabre Lite board uses UART2. So the first change is to make the
In board/freescale/mx6sabresd/mx6sabresd.c
Add following to support UART2.
static iomux_v3_cfg_t const uart2_pads[] = {
;
IOMUX_PADS(PAD_EIM_D26__UART2_TX_DATA | MUX_PAD_CTRL(UART_PAD_CTRL)),
IOMUX_PADS(PAD_EIM_D27__UART2_RX_DATA | MUX_PAD_CTRL(UART_PAD_CTRL)),
}
Also add
SETUP_IOMUX_PADS(uart2_pads)
in setup_iomux_uart
static void setup_iomux_uart(void)
{
SETUP_IOMUX_PADS(uart1_pads);
SETUP_IOMUX_PADS(uart2_pads);
}
Compile using
make mx6sabresd_defconfig
make
Since the SPL mode is supported by default - use the following two stage commands to flash the SD Card with
sudo dd if=SPL of=/dev/sdc bs=1k seek=1
sudo dd if=u-boot.img of=/dev/sdc bs=1k seek=69
Please note that this assumes the u-boot to be in the SD Card. This will require that the fuse in the Sabre Lite is not programed for EEPROM
At this point the board is able to boot with following errors
The MMC Card is not detected and the reason is that the Card Detect Pin is different in Sabre SD and the Sabre Lite.
This required following fixes
1.In board/freescale/mx6sabresd/mx6sabresd.c replace
#define USDHC3_CD_GPIO IMX_GPIO_NR(2, 0)
by
#define USDHC3_CD_GPIO IMX_GPIO_NR(7, 0)
2. Make following changes in usdhc3_pads
static iomux_v3_cfg_t const usdhc3_pads[] = {
IOMUX_PADS(PAD_SD3_CLK__SD3_CLK | MUX_PAD_CTRL(USDHC_PAD_CTRL)),
IOMUX_PADS(PAD_SD3_CMD__SD3_CMD | MUX_PAD_CTRL(USDHC_PAD_CTRL)),
IOMUX_PADS(PAD_SD3_DAT0__SD3_DATA0 | MUX_PAD_CTRL(USDHC_PAD_CTRL)),
IOMUX_PADS(PAD_SD3_DAT1__SD3_DATA1 | MUX_PAD_CTRL(USDHC_PAD_CTRL)),
IOMUX_PADS(PAD_SD3_DAT2__SD3_DATA2 | MUX_PAD_CTRL(USDHC_PAD_CTRL)),
IOMUX_PADS(PAD_SD3_DAT3__SD3_DATA3 | MUX_PAD_CTRL(USDHC_PAD_CTRL)),
IOMUX_PADS(PAD_SD3_DAT4__SD3_DATA4 | MUX_PAD_CTRL(USDHC_PAD_CTRL)),
/*
IOMUX_PADS(PAD_SD3_DAT5__SD3_DATA5 | MUX_PAD_CTRL(USDHC_PAD_CTRL)),
*/
IOMUX_PADS(PAD_SD3_DAT6__SD3_DATA6 | MUX_PAD_CTRL(USDHC_PAD_CTRL)),
IOMUX_PADS(PAD_SD3_DAT7__SD3_DATA7 | MUX_PAD_CTRL(USDHC_PAD_CTRL)),
/*
IOMUX_PAD_CTRL(SD3_DAT5__GPIO7_IO00, WEAK_PULLUP),
*/
IOMUX_PADS(PAD_SD3_DAT5__GPIO7_IO00 | MUX_PAD_CTRL(NO_PAD_CTRL)), /* CD */
/*
IOMUX_PADS(PAD_NANDF_D0__GPIO2_IO00 | MUX_PAD_CTRL(NO_PAD_CTRL)),
*/
The board proceeds but stops at next error
As a quick and dirty fix, returned in the beginning of power_init_board without checking for Power ICs in board/freescale/mx6sabresd/mx6sabresd.c .
int power_init_board(void)
{
struct pmic *p;
unsigned int reg;
int ret;
// Vikas dirty return to be fixed
return 0;
p = pfuze_common_init(I2C_PMIC);
if (!p)
return -ENODEV;
.
.
.
Hello,
nice post ! Thanks.
I have a sabre lite too but unfortunately the Fuses are configured to boot by SPI EEPROM.
How did you do to find a sabre lite with not burned BOOT Efuses?
Regards
sk