On Fri, Apr 01, 2016 at 09:14:15PM -0600, Stephen Warren wrote: > On all Pis so far, the VC FW provides a short stub to set up the ARM CPU > before entering the kernel (a/k/a U-Boot for us). This feature is not > currently supported by the VC FW when booting in 64-bit mode. However, > this feature will likely appear in the near future, and this U-Boot port > assumes that such a feature is in place. Without that feature, or a > temporary workaround described below, U-Boot will not boot. > > Once the VC FW does provide the ARM stub, u-boot.bin built for rpi_3 can > be used drectly as kernel7.img, in the same way as any other RPi port. The > following config.txt is required: > > # Fix mini UART input frequency, and setup/enable up the UART. > # Without this option, U-Boot will not boot, even if you don't care > # about the serial console. This option will always be required for > # all RPi3 use-cases, unless the PL011 UART is used, which is not > # yet supported by rpi_3* builds of U-Boot. > enable_uart=1 > # Boot in AArch64 (64-bit) mode. > # It is possible that a future VC FW will remove the need for this > # option, instead auto-setting 32-/64-bit mode based on the "kernel" > # filename present on the SD card. > arm_control=0x200 > > Prior to the VC FW providing the ARM boot stub, you can use the following > steps to build an equivalent stub into the U-Boot binary: > > git clone https://github.com/swarren/rpi-3-aarch64-demo.git \ > ../rpi-3-aarch64-demo > (cd ../rpi-3-aarch64-demo && ./build.sh) > Build U-Boot for rpi_3 in the usual way > cat ../rpi-3-aarch64-demo/armstub64.bin u-boot.bin > u-boot.bin.stubbed > Use u-boot.bin.stubbed as kernel7.img on the Pi SD card. > > In this case, the following additional entries are required in config.txt: > > # Tell the FW to load the kernel image at address 0, the reset vector. > kernel_old=1 > > Signed-off-by: Stephen Warren <swar...@wwwdotorg.org> > Reviewed-by: Tom Rini <tr...@konsulko.com>
Applied to u-boot/master, thanks! -- Tom
signature.asc
Description: Digital signature
_______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
