| Samuel Holland | 7438320 | 2017-08-12 04:07:39 -0500 | [diff] [blame] | 1 | Trusted Firmware-A for Allwinner ARMv8 SoCs |
| 2 | =========================================== |
| 3 | |
| 4 | Trusted Firmware-A (TF-A) implements the EL3 firmware layer for Allwinner |
| 5 | SoCs with ARMv8 cores. Only BL31 is used to provide proper EL3 setup and |
| 6 | PSCI runtime services. |
| 7 | U-Boot's SPL acts as a loader, loading both BL31 and BL33 (typically U-Boot). |
| 8 | Loading is done from SD card, eMMC or SPI flash, also via an USB debug |
| 9 | interface (FEL). |
| 10 | BL31 lives in SRAM A2, which is documented to be accessible from secure |
| 11 | world only. |
| 12 | |
| 13 | Current limitations: |
| 14 | |
| 15 | - Missing PMIC support |
| 16 | |
| 17 | After building bl31.bin, the binary must be fed to the U-Boot build system |
| 18 | to include it in the FIT image that the SPL loader will process. |
| 19 | bl31.bin can be either copied (or sym-linked) into U-Boot's root directory, |
| 20 | or the environment variable BL31 must contain the binary's path. |
| 21 | See the respective `U-Boot documentation`_ for more details. |
| 22 | |
| 23 | To build: |
| 24 | |
| 25 | :: |
| 26 | |
| 27 | make CROSS_COMPILE=aarch64-linux-gnu- PLAT=sun50i_a64 DEBUG=1 bl31 |
| 28 | |
| 29 | .. _U-Boot documentation: http://git.denx.de/?p=u-boot.git;f=board/sunxi/README.sunxi64;hb=HEAD |