MicroSD Breakout



The cubieboard MicroSD breakout board provides JTAG and UART over the SD-Card connector. The UART connector is a 5 pin JST-XH.

U-Boot output to sdcard UART
For booting, apply the FEL/USBBoot procedure.

u-boot-sunxi
Add 'UART0_PORT_F' to the option of the *_FEL line of your board in boards.cfg. Make sure it also contains 'SPL_FEL' instead of 'SPL'.

Mainline U-Boot
First, to setup u-boot for FEL mode, use &lt;board>_felconfig instead of the usual &lt;board>_defconfig.

Then, set in both CONFIG_UART0_PORT_F=y
 * .config
 * spl/.conf

Alternatively, you can set the variables via menuconfig, but again you have to do this twice: ARM architecture ---> [*] SPL/FEL mode support [*] UART0 on MicroSD breakout board Compile as usual.
 * make menuconfig
 * make spl/menuconfig

sunxi-3.4 kernel
Some FEX modifications are needed. An example for A13:  @@ -31,13 +31,13 @@ sdc_d2 = port:PF05<2><1> twi_port = 0 twi_scl = port:PB00<2><1> twi_sda = port:PB01<2><1> [uart_para] -uart_debug_port = 1 -uart_debug_tx = port:PG03<4><1> -uart_debug_rx = port:PG04<4><1> +uart_debug_port = 0 +uart_debug_tx = port:PF02<4><1> +uart_debug_rx = port:PF04<4><1> [jtag_para] jtag_enable = 0 jtag_ms = port:PF00<4><1> jtag_ck = port:PF05<4><1> @@ -112,15 +112,15 @@ twi1_sda = port:PB16<2> twi2_used = 1 twi2_scl = port:PB17<2> twi2_sda = port:PB18<2> [uart_para0] -uart_used = 0 +uart_used = 1 uart_port = 0 uart_type = 2 -uart_tx = port:PB19<2><1> -uart_rx = port:PB20<2><1> +uart_tx = port:PF02<4><1> +uart_rx = port:PF04<4><1> [uart_para1] uart_used = 1 uart_port = 1 uart_type = 2 @@ -351,11 +351,11 @@ csi_power_en_b = csi_stby_b = csi_flash_b = csi_af_en_b = [mmc0_para] -sdc_used = 1 +sdc_used = 0 sdc_detmode = 1 bus_width = 4 sdc_d1 = port:PF00<2><1><2> sdc_d0 = port:PF01<2><1><2> sdc_clk = port:PF02<2><1><2>

mainline kernel
TBD

Breakout boards

 * microSD Sniffer (@sparkfun.com) - header needs to be soldered.
 * SD to MicroSD/TransFlash Card Converter Module (@dealextreme.com) - has mini pins inside.

Buy
Buy from Tom Cubie's site.