jonlamb-gh / rpi4-rust-workspace

Rust workspace for Raspberry Pi 4 bare metal things

rpi4-rust-workspace

Rust workspace for RPi4 bare metal things

A lot of the things in here were inspired by rust-raspi3-OS-tutorials and circle.

Crates

• bcm2711 : Device crate, registers defined via bounded-registers
• bcm2711-hal : embedded-hal trait impls
• display : Double buffered DMA graphics/display library
• rtsp : RTSP library
• rtp : RTP library
• smoltcp-phy : smoltcp Phy
• rtp-jpeg-decoder : RTP JPEG decoder library
• uplot : Small plotting library using embedded-graphics primitives
• raspi3_boot : Mostly copied from rust-raspi3-OS-tutorials

Examples

• analog-clock : Port of the embedded-graphics analog-clock example
• embedded-graphics : Simple embedded-graphics example
• eth : On-board GENET Ethernet example
• ip : smoltcp IP stack / TCP server example
• mbox : Reads various things using the Mailbox property interface
• mem2mem-dma : Simple DMA transfer example
• uart1 : UART1 example
• ipcam-viewer : ip-camera RTSP client and image display
• temperature-plot : Plots the internal temperature

Building

rustc 1.44.0-nightly (94d346360 2020-04-09)

cargo xbuild

Copy elf to binary:

cargo objcopy -- -O binary target/$(TARGET)/release/img /tmp/img.bin

Simulating

Comming soon?

https://gitlab.com/philmd/qemu/commits/raspi4_wip

# For output on UART1
qemu-system-aarch64 -M raspi4 -nographic -serial null -serial mon:stdio -kernel /path/to/binary

TODO - cusomer runner / cargo xrun support:

[target.'cfg(target_os = "none")']
runner = "tools/qemu-runner"

U-boot

Using 64 bit U-boot:

git clone --depth 1 https://github.com/u-boot/u-boot.git u-boot
ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- make rpi_4_defconfig
ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- make

U-Boot 2020.04-rc2-00048-gf2a73d6867 (Feb 16 2020 - 08:29:41 -0800)

aarch64-linux-gnu-gcc (Ubuntu/Linaro 8.3.0-6ubuntu1) 8.3.0
GNU ld (GNU Binutils for Ubuntu) 2.32

Environment:

setenv imgname img.bin

# Normally for bare metal
#setenv loadaddr 0x80000

# Put it somewhere else, so we don't overwrite u-boot
setenv loadaddr 0x01000000

# Make sure the caches are on
setenv bootimg 'tftp ${loadaddr} ${serverip}:${imgname}; dcache flush; dcache on; go ${loadaddr}'

SD Card

Files:

/card
├── config.txt
├── fixup4.dat
├── start4.elf
├── u-boot.bin
└── uboot.env

Contents of config.txt:

enable_uart=1
arm_64bit=1
kernel=u-boot.bin

Links

• BCM2711
• RPi4 datasheet
• Revised BCM2837 doc
• bcm2711-rpi-4-b.dtb

rpi4-rust-workspace's Issues

The HAL crate prelude should provide more things

Replace Void with Infallible

Fill out the driver impl's once the docs are available

Coming soon?
https://www.raspberrypi.org/forums/viewtopic.php?f=72&t=244479&sid=3bbf22a36500b2047fe914894e8b2bd0#p1491246

Redo DMA

rpi4-rust-workspace/bcm2711-hal/src/dma/mod.rs

Line 3 in 088afcc

// TODO

Add EMMC/sd-card interface

Use it to read the u-boot environment file for key/value storage.
Update IP examples to pull in the ipaddr env variable.

Redo the linker script

https://blog.japaric.io/stack-overflow-protection/

Investigate if the 2711 has a different mechanism for pin pull-up/down/enable

• https://github.com/RPi-Distro/raspi-gpio/blob/master/raspi-gpio.c#L194
• https://github.com/rsta2/circle/blob/fe24b6bebd1532f2a0ee981af12eaf50cc9e97fb/include/circle/bcm2835.h#L73
• https://github.com/rsta2/circle/blob/fe24b6bebd1532f2a0ee981af12eaf50cc9e97fb/lib/gpiopin.cpp#L350

Enable the data cache and add maintenance routines

Currently leaning on u-boot to disable the dcache.
Some examples over in the Circle project