| Svyatoslav Ryhel | 8178e89 | 2023-06-29 10:10:26 +0300 | [diff] [blame] | 1 | .. SPDX-License-Identifier: GPL-2.0+ |
| 2 | |
| 3 | U-Boot for the Nvidia Tegra Note 7 |
| 4 | ================================== |
| 5 | |
| 6 | Quick Start |
| 7 | ----------- |
| 8 | |
| 9 | - Build U-Boot |
| 10 | - Boot U-Boot by loading it into RAM (coldboot) |
| 11 | - Chainloading U-Boot from the vendor bootloader |
| 12 | - Boot |
| 13 | |
| 14 | Build U-Boot |
| 15 | ------------ |
| 16 | |
| 17 | U-Boot can be built in two forms: U-Boot with SPL, which is used for booting |
| 18 | by loading directly into RAM and U-Boot without SPL, which can be flashed |
| 19 | and chainloaded from the vendor bootloader. |
| 20 | |
| 21 | To build U-Boot with SPL proseed: |
| 22 | |
| 23 | .. code-block:: bash |
| 24 | |
| 25 | $ export CROSS_COMPILE=arm-none-eabi- |
| 26 | $ make tegratab_defconfig |
| 27 | $ make |
| 28 | |
| 29 | After the build succeeds, you will obtain the final ``u-boot-dtb-tegra.bin`` |
| 30 | file, ready for cold booting by loading into RAM. |
| 31 | |
| 32 | To build U-Boot without SPL adjust tegratab_defconfig: |
| 33 | |
| 34 | .. code-block:: |
| 35 | |
| 36 | CONFIG_TEXT_BASE=0x80A00000 |
| 37 | CONFIG_SKIP_LOWLEVEL_INIT=y |
| 38 | # CONFIG_OF_BOARD_SETUP is not set |
| 39 | CONFIG_TEGRA_SUPPORT_NON_SECURE=y |
| 40 | |
| 41 | After the build succeeds, you will obtain the final ``u-boot-dtb.bin`` file, |
| 42 | ready for booting with fastboot boot or which can be further processed into |
| 43 | a flashable boot.img. |
| 44 | |
| 45 | Boot U-Boot by loading it into RAM (coldboot) |
| 46 | --------------------------------------------- |
| 47 | |
| 48 | Done fairly simply by using fusee-tools (using run_bootloader.sh) and placing |
| 49 | ``u-boot-dtb-tegra.bin`` generated on the previous step into fusee-tools dir. |
| 50 | This method requires constant access to the host PC or payloader and can fully |
| 51 | eliminate influence of the vendor bootloader onto the boot process. |
| 52 | |
| 53 | .. code-block:: bash |
| 54 | |
| 55 | $ ./run_bootloader.sh -s T114 -t ./bct/tegratab.bct |
| 56 | |
| 57 | Chainloading U-Boot from the vendor bootloader |
| 58 | ---------------------------------------------- |
| 59 | |
| 60 | ``u-boot-dtb.bin`` has to be further packed into Android boot image form, |
| 61 | where ``u-boot-dtb.bin`` acts as kernel, while dtb and ramdisk parts should |
| 62 | not be included. Then the generated boot image can be flashed into the /boot |
| 63 | partition of the tablet using vendor bootloader's fastboot and will act as |
| 64 | the bootloader of the last stage. |
| 65 | |
| 66 | Boot |
| 67 | ---- |
| 68 | In both cases after U-Boot obtains control it performs search of extlinux.conf |
| 69 | first on the dock USB device is available, then on MicroSD card if available |
| 70 | and lastly on eMMC. If none of the devices above are present, then the device |
| 71 | is turned off. |
| 72 | |
| 73 | If during boot of U-Boot Volume Down button is pressed, the device will enter |
| 74 | U-Boot bootmenu. |