On 09/05/2014 01:52 PM, Semion Prihodko wrote: > This is tricky to deepen in this large code base. It looks strange that > there's no simple concrete tutorial like we have for all other CPU > architectures (e.g. in osdev.org <http://osdev.org>).
AArch64 hasn't really changed the PL011 UART (nor GIC, nor VirtIO-MMIO, nor semihosting, although maybe DCC a little) as far as I recall. The UART functions from the following article are probably reusable. http://wiki.osdev.org/ARM_Integrator-CP_IRQTimerAndPIC Among other things, AArch64 is pretty new compared to the other architectures on osdev.org. If you get something going, maybe you can write the tutorial. Christopher > 05 Сен 2014 г. 19:57 пользователь "Claudio Fontana" > <claudio.font...@huawei.com <mailto:claudio.font...@huawei.com>> написал: > > On 05.09.2014 16 <tel:05.09.2014%2016>:50, Semion Prihodko wrote: > > Let's discard semihosting. I have aarch64-linux-gnu-* toolchain and > > qemu-system-aarch64 emulator. How can I build a minimal kernel which > > outputs Hello World! via serial port and run it on the emulator? > > > > If you run qemu with the "virt" platform, you can write to the UART at > 0x9000000 > to get a character out, works very early. > > You could check the AArch64 port of the OSv Operating System, has a simple > boot loader > you can look at (arch/aarch64/preboot.S and arch/aarch64/boot.S) > and the pl011 device you find in drivers/pl011.cc > > https://github.com/cloudius-systems/osv/wiki/AArch64 > > Good luck, > > Claudio > > > > > 2014-09-04 21:15 GMT+03:00 Christopher Covington <c...@codeaurora.org > <mailto:c...@codeaurora.org>>: > > > >> Hi Semion, > >> > >> On 09/04/2014 09:40 AM, Semion Prihodko wrote: > >>> Still don't know how to build/run a simple Hello World kernel on > >>> qemu-system-aarch64? > >>> > >>> Guys, this is a very basic thing, please provide concrete steps. > Thanks. > >> > >> Here you go. Start at the wget. > >> > >> http://lists.gnu.org/archive/html/qemu-devel/2014-07/msg03487.html > >> > >> Angel semihosting isn't implemented upstream so a text hello world > won't be > >> trivial, although given enough time it should be possible to implement > >> Angel > >> semihosting for A64 in QEMU, implement DCC in QEMU and Newlib/libgloss > or > >> implement PL011 UART or VirtIO-MMIO console in Newlib/libgloss. > >> > >> Some of the bootloaders and firmwares out there (bootwrapper, ARM > trusted > >> firmware, UEFI/Tianocore) may have examples of using the PL011 UART. > >> > >> Christopher > >> > >> -- > >> Employee of Qualcomm Innovation Center, Inc. > >> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, > >> hosted by the Linux Foundation. > >> > -- Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by the Linux Foundation.
