1How to use and build U-Boot on mx6sabresd
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3
4The following methods can be used for booting mx6sabresd boards:
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61. Booting from SD card
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82. Booting from eMMC
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103. Booting via Falcon mode (SPL launches the kernel directly)
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12
131. Booting from SD card via SPL
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16mx6sabresd_defconfig target supports mx6q/mx6dl/mx6qp sabresd variants.
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18In order to build it:
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20$ make mx6sabresd_defconfig
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22$ make
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24This will generate the SPL and u-boot-dtb.img binaries.
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26- Flash the SPL binary into the SD card:
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28$ sudo dd if=SPL of=/dev/sdX bs=1K seek=1 && sync
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30- Flash the u-boot-dtb.img binary into the SD card:
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32$ sudo dd if=u-boot-dtb.img of=/dev/sdX bs=1K seek=69 && sync
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34
352. Booting from eMMC
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37
38$ make mx6sabresd_defconfig
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40$ make
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42This will generate the SPL and u-boot-dtb.img binaries.
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44- Boot first from SD card as shown in the previous section
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46In U-boot change the eMMC partition config:
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48=> mmc partconf 2 1 0 0
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50Mount the eMMC in the host PC:
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52=> ums 0 mmc 2
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54- Flash SPL and u-boot-dtb.img binaries into the eMMC:
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56$ sudo dd if=SPL of=/dev/sdX bs=1K seek=1 && sync
57$ sudo dd if=u-boot-dtb.img of=/dev/sdX bs=1K seek=69 && sync
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59Set SW6 to eMMC 8-bit boot: 11010110
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623. Booting via Falcon mode
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64
65$ make mx6sabresd_defconfig
66$ make
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68This will generate the SPL image called SPL and the u-boot-dtb.img.
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70- Flash the SPL image into the SD card:
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72$ sudo dd if=SPL of=/dev/sdX bs=1K seek=1 oflag=sync status=none && sync
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74- Flash the u-boot-dtb.img image into the SD card:
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76$ sudo dd if=u-boot-dtb.img of=/dev/sdX bs=1K seek=69 oflag=sync status=none && sync
77
78Create a partition for root file system and extract it there:
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80$ sudo tar xvf rootfs.tar.gz -C /media/root
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82The SD card must have enough space for raw "args" and "kernel".
83To configure Falcon mode for the first time, on U-Boot do the following commands:
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85- Setup the IP server:
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87# setenv serverip <server_ip_address>
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89- Download dtb file:
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91# dhcp ${fdt_addr} imx6q-sabresd.dtb
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93- Download kernel image:
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95# dhcp ${loadaddr} uImage
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97- Write kernel at 2MB offset:
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99# mmc write ${loadaddr} 0x1000 0x4000
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101- Setup kernel bootargs:
102
103# setenv bootargs "console=ttymxc0,115200 root=/dev/mmcblk1p1 rootfstype=ext4 rootwait quiet rw"
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105- Prepare args:
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107# spl export fdt ${loadaddr} - ${fdt_addr}
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109- Write args 1MB data (0x800 sectors) to 1MB offset (0x800 sectors)
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111# mmc write 18000000 0x800 0x800
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113- Press KEY_VOL_UP key, power up the board and then SPL binary will
114launch the kernel directly.
115