diff options
Diffstat (limited to 'qemu/roms/u-boot/doc/README.arm64')
| -rw-r--r-- | qemu/roms/u-boot/doc/README.arm64 | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/qemu/roms/u-boot/doc/README.arm64 b/qemu/roms/u-boot/doc/README.arm64 new file mode 100644 index 000000000..75586dbaa --- /dev/null +++ b/qemu/roms/u-boot/doc/README.arm64 @@ -0,0 +1,46 @@ +U-boot for arm64 + +Summary +======= +No hardware platform of arm64 is available now. The u-boot is +simulated on Foundation Model and Fast Model for ARMv8. + +Notes +===== + +1. Currenly, u-boot run at the highest exception level processor + supported and jump to EL2 or optionally EL1 before enter OS. + +2. U-boot for arm64 is compiled with AArch64-gcc. AArch64-gcc + use rela relocation format, a tool(tools/relocate-rela) by Scott Wood + is used to encode the initial addend of rela to u-boot.bin. After running, + the u-boot will be relocated to destination again. + +3. Fdt should be placed at a 2-megabyte boundary and within the first 512 + megabytes from the start of the kernel image. So, fdt_high should be + defined specially. + Please reference linux/Documentation/arm64/booting.txt for detail. + +4. Spin-table is used to wake up secondary processors. One location + (or per processor location) is defined to hold the kernel entry point + for secondary processors. It must be ensured that the location is + accessible and zero immediately after secondary processor + enter slave_cpu branch execution in start.S. The location address + is encoded in cpu node of DTS. Linux kernel store the entry point + of secondary processors to it and send event to wakeup secondary + processors. + Please reference linux/Documentation/arm64/booting.txt for detail. + +5. Generic board is supported. + +6. CONFIG_ARM64 instead of CONFIG_ARMV8 is used to distinguish aarch64 and + aarch32 specific codes. + +Contributor +=========== + Tom Rini <trini@ti.com> + Scott Wood <scottwood@freescale.com> + York Sun <yorksun@freescale.com> + Simon Glass <sjg@chromium.org> + Sharma Bhupesh <bhupesh.sharma@freescale.com> + Rob Herring <robherring2@gmail.com> |