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).
05 Сен 2014 г. 19:57 пользователь "Claudio Fontana" <
address@hidden> написал:
On 05.09.2014 16:50, 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 <address@hidden>:
>
>> 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.
>>