64 bit Bare Metal Programming on RPI-3 Your first aarch64 bare metal program

by Tristan Gingold

At: FOSDEM 2017

The Raspberry PI 3 board is very popular, but mainly known as a Linuxplatform. But it could also be used to do bare metal development: writing low-level code without any OS. There are almost no tutorials on the internetaddressing the main new feature of the RPI-3 board: 4x 64 bit cores (previousgenerations were 32 bit). Let's fill the gap by this lightening talk: a veryshort presentation of the board, how to write and build a first example and ademo of a more advanced multi-core application.

Room: H.2215 (Ferrer)
Scheduled start: 2017-02-04 14:40:00

[flyxtop]

what does he say in 6:28 ? first file to be executed by the {....} C run time ?

[macsimbodnar]

I have errors during compiling on assembly script:
crt0.S: Assembler messages:
crt0.S:11: Error: ARM register expected -- `mrs x7, mpidr_el1'
crt0.S:12: Error: ARM register expected -- `and x7, x7, #3'
crt0.S:13: Error: selected processor does not support `cbz x7, __start_master' in ARM mode
crt0.S:14: Error: selected processor does not support `wfe' in ARM mode
crt0.S:19: Error: bad instruction `adrp x2, __cpu0_stack_end'
crt0.S:20: Error: ARM register expected -- `add x2, x2, #:lo12:__cpu0_stack_end'
crt0.S:21: Error: immediate expression requires a # prefix -- `mov sp, x2'
crt0.S:24: Error: ARM register expected -- `ldr w0, bss_segment+0'
crt0.S:25: Error: ARM register expected -- `ldr w1, bss_segment+4'
crt0.S:26: Error: selected processor does not support `cbz x1, 1f' in ARM mode
crt0.S:27: Error: ARM register expected -- `str xzr, [x0], #8'
crt0.S:28: Error: ARM register expected -- `sub x1, x1, #1'
crt0.S:29: Error: selected processor does not support `cbnz x1, 0b' in ARM mode
<builtin>: recipe for target 'crt0.o' failed

[jeanvaljean]

As a french guy, I must admit that french accent in english is horrible to hear...