STICKY: Bare Metal resources

[mahjongg]

Links to resources for Bare Metal programming go here.

Please do not post comments/discussions here, just links to info.
Post "contaminating" the sticky will be deleted.
For these use the normal threads.

[mahjongg]

headers from the Broadcom GPU source code

• SD - for SDRAM
• L1 - for Level 1 cache
• L2 - for Level 2 cache
• H264 - for the H264 encoder/devoder i assume
• FPGA - ?

The generated html page is here:
https://rawgithub.com/msperl/rpi-regist ... sters.html

The full project including the scripts which were used to generate it can be found here:
https://github.com/msperl/rpi-registers

[mahjongg]

BCM2835-ARM-Peripherals:

http://www.raspberrypi.org/wp-content/u ... herals.pdf

and its errata info

http://elinux.org/BCM2835_datasheet_errata

GPIO-Pads-Control:

http://www.scribd.com/doc/101830961/GPIO-Pads-Control2

ARM1176JZFS technical documentation:

http://infocenter.arm.com/help/topic/co ... p7_trm.pdf

bare metal programming WiKi:

http://en.wikibooks.org/wiki/Bare-metal ... rogramming

[ghans]

Information for the Raspberry Pi / BCM2835

• ARMv6-M Architecture Reference Manual ("ARM ARM" , DDI 0419C)
  https://c4everyone.com/pub/ARM/DDI0419C.pdf
• ARM1176JZF-S Technical Reference Manual
  http://infocenter.arm.com/help/topic/co ... p7_trm.pdf
• Peripherials documentation
  http://www.raspberrypi.org/wp-content/u ... herals.pdf

Information for the Raspberry Pi 2 / BCM2836

• Peripherials documementation
  https://www.raspberrypi.org/documentati ... rev3.4.pdf
• ARM Cortex-A7 Technical Reference Manual ("ARM TRM" , DDI 0464F)
  http://infocenter.arm.com/help/index.js ... index.html
• ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition ("ARM ARM" , DDI 0406C)
  http://infocenter.arm.com/help/index.js ... index.html

Information for the BCM2837 (Raspberry Pi 3)

• Peripherials documementation (same as Raspberry Pi 2)
  https://www.raspberrypi.org/documentati ... rev3.4.pdf
• ARM Cortex-A53 MPCore Processor Technical Reference Manual
  http://infocenter.arm.com/help/topic/co ... p2_trm.pdf
• ARMv8 Architecture Reference Manual
  https://people.mozilla.org/~sstangl/arm ... Manual.pdf

NEW ! Information for the BCM2711 (Raspberry Pi 4)

• Peripherials documementation
  https://datasheets.raspberrypi.org/bcm2 ... herals.pdf
• ARM Cortex-A72 MPCore Processor Technical Reference Manual
  https://documentation-service.arm.com/s ... b61?token=
• ARMv8 Architecture Reference Manual
  https://people.mozilla.org/~sstangl/arm ... Manual.pdf

Communicating with the GPU via Mailboxes

https://github.com/raspberrypi/firmware/wiki
https://github.com/raspberrypi/firmware/wiki/_pages

ghans

[ghans]

The USB Controller on the Pi has no official publicly available documentation.
As USB was envisaged as the main way of connecting a keyboard plus mouse AND getting an
internet connection, this might be unfortunate for everybody who writes their own OS.
Currently information on the controller has to be gleaned from open drivers.
The one of the embedded Xinu project might be a good starting point:

http://xinu.mscs.mu.edu/Synopsys_Design ... Controller

Otherwise , have a look at the USPi project of R. Stange , which
is ready for integration in your open-source projects (GPLv3) :
http://www.raspberrypi.org/forums/viewt ... 72&t=92579

GPU Documentation / VideoCore® IV 3D Architecture Reference Guide
https://docs.broadcom.com/docs/12358545


More documentation for the GPU (reverse-engineered) :
https://github.com/hermanhermitage/videocoreiv

Documentation for the LAN9512 chip of the Model B (an USB hub with an integrated USB Network card):
http://ww1.microchip.com/downloads/en/D ... c/9512.pdf

ghans

[mahjongg]

(bare metal) boot resources:

http://raspberrypi.stackexchange.com/qu ... t-sequence
http://thekandyancode.wordpress.com/201 ... -boots-up/
http://www.raspberrypi.org/forums/viewt ... =63&t=6685

Thanks Ghans.

[ghans]

David Welchs bare metal examples :

https://github.com/dwelch67/raspberrypi

Also includes code which illustrates how to load new
kernels over a serial connection , so you don't need to
constantly swap the SD card from the Pi to your dev machine
and back.

Baking Pi :
http://www.cl.cam.ac.uk/projects/raspbe ... orials/os/

A nice tutorial on writing bare-metal assembly for the Pi.

ghans

[macload1]

Link to an example of Raspberry Pi running FreeRTOS and µGFX as GUI using the framebuffer (output on HDMI or composite)

-> http://macload1.frogcp.com

[krom]

Here are some Bare Metal Raspberry Pi examples that use very minimal & simple ARM Assembly only:
https://github.com/PeterLemon/RaspberryPi

Here is what you will find:
LZSS & Huffman Decompression: https://github.com/PeterLemon/Raspberry ... r/Compress
GB Z80 Emulator with minimal hardware attached to run some GameBoy ROMs: https://github.com/PeterLemon/Raspberry ... MU/GameBoy
Hello World console text output demos, using the CPU or DMA with Stride: https://github.com/PeterLemon/Raspberry ... HelloWorld
GPIO Input demos using a SNES or NES Controller, & the SNES Mouse: https://github.com/PeterLemon/Raspberry ... ster/Input
Sound Playback demos using the PWM: https://github.com/PeterLemon/Raspberry ... /Sound/PWM
TAGS Channel demo which prints all Raspberry Pi Mailbox TAGS information to the screen: https://github.com/PeterLemon/Raspberry ... agsChannel
V3D demos to show howto initialize the V3D (Rasperry Pi GPU) & prints all V3D information to the screen, & howto display a control list to show a Clear Color & Triangles: https://github.com/PeterLemon/Raspberry ... master/V3D
VFP demos to display a static Mandelbrot fractal using Raspberry Pi ARM Floating point (FPU) instructions, & an animated Julia fractal: https://github.com/PeterLemon/Raspberry ... FP/Fractal

You will not find a simpler suite of assembly source for bare metal programming on the Raspberry Pi, I recommend you check out my github repository if you like programming in ARM assembly.
I hope you all have fun with this stuff!

P.S I would like to say a special thanks to DexOS who helped me get my 1st pixel on the screen, & made all this possible =D

[novellus]

A couple C based bare metal examples
https://github.com/novellus/Bare-Metal- ... -Pi-Kernel

[mrvn]

Raspberry Pi
The Raspberry Pi has 5 LEDs on the board: Power, Activity, Full Douplex, Link and 100Mbit. The last 3 I assume are connected directly to the ethernet chip. I'm unsure about the power LED. The activity LED though is connected to GPIO pin 16 and configured for output on boot. One can simply set/clr the pin to make the LED react.

Note: peripheral base in 0x20000000 which makes the GPIO base 0x20200000.

Raspberry Pi2
The Raspbeery PI2 has only 2 LEDs on the board: Power and Activity. The RJ45 connector has 2 more LEDs but they will be controled by the ethernet chip for sure. The power LED is connected to GPIO pin 35 but configured at boot with pull up or pull down so it simply is on. Removing the pull up/down and reconfiguring the pin for output lets one control the LED via set/clr of the pin. The activity LED has moved compared to the Raspberry Pi and is now on GPIO pin 47. But it is still configured as output on boot and set/clr of the pin makes it react.

Note: peripheral base in 0x3F000000 which makes the GPIO base 0x3F200000.

[turboscrew]

How about Pi 2 USB?
I understand that for RasPi A, there is one USB: the Synopsys' module built into the VideoCore IV, that is directly connected to the USB-connector. In RasPi B, that same module is used, but connected to the integrated USB HUB in LAN9512, but how about Pi B+ and Pi 2? It has 4 USB ports, but they were not found in the schema.

[rpdom]

The Pi 2 and B+ use a LAN9514 instead of a LAN9512. It's the same chip, but with 4 USB ports instead of 2.

[sheroy]

One more bare metal development link in c

This is a bit higher by using c but essentially instead of writing in assembly one can write in c

http://www.valvers.com/open-software/ra ... g-in-cpt1/

[rascol]

A VideoCoreIV assembler: http://maazl.de/project/vc4asm/doc/index.html

[Akane]

VideoCore IV 3D Architecture Reference Guide errata: http://elinux.org/VideoCore_IV_3D_Archi ... ide_errata

[Akane]

• qpu-trivial-assembler -- An assembler for VideoCore IV QPU: https://github.com/Terminus-IMRC/qpu-trivial-assembler
• mailbox -- Library for accessing the Mailbox Interface on VideoCore IV: https://github.com/Terminus-IMRC/mailbox
• mailboxinfo -- Print information from the Mailbox Interface of VideoCore IV: https://github.com/Terminus-IMRC/mailboxinfo
• libvc4v3d -- Library for accessing VideoCore IV V3D: https://github.com/Terminus-IMRC/libvc4v3d
• libvc4vec -- Library for vector calculations on VideoCore IV QPU: https://github.com/Terminus-IMRC/libvc4vec
• qpuinfo -- Print information from VideoCore IV V3D: https://github.com/Terminus-IMRC/qpuinfo
• vpu_cpuid -- Print cpuid of VideoCore IV VPU: https://github.com/Terminus-IMRC/vpu_cpuid

[27troadster]

Coprocessor register values upon boot to bare metal:

viewtopic.php?f=72&t=126891

[ausppc]

From https://en.wikipedia.org/wiki/Raspberry_Pi

CPU for models A, A+, B, B+, CM & Pi Zero : ARM1176JZF-S
Links to useful reference material: https://en.wikipedia.org/wiki/ARM11#External_links

CPU for Pi 2 : ARM Cortex-A7
No useful links.

[Ultibo]

Full featured Raspberry Pi bare metal in Free Pascal

https://ultibo.org

Includes threading, networking, filesystems, USB, MMC/SD and more.

[sharpcoder]

complete c++ kernel for the raspberry pi: https://github.com/SharpCoder/rpi-kernel
And the guide on how to compile it: https://rpidev.wordpress.com

The kernel was developed with a raspberry A. Though it should work on newer ones (as far as I am aware). The code is mostly pretty well commented and does its best to be as comprehensible as possible.

[dickon]

This may be of use to some: Cypress have bought Broadcom's wifi business and released all the docs. They're at http://www.cypress.com/search/all?f%5B0 ... s%3A110101 with the Pi3's wifi / BT controller at http://www.cypress.com/documentation/da ... _documents.

[colinh]

Peter Cockerell's ARM Assembly Language Programming book

This excellent book is a wonderful introduction to ARM assembler. It deals with the ancient ARM2 processor (as used in the original Acorn Archimedes computer - back when ARM was Acorn RISC machine ) but almost all of it is still relevant.

Pete has kindly made it available for free at http://www.peter-cockerell.net/aalp/html/frames.html

The full book as a single (zipped) pdf file is at: http://peter-cockerell.net/aalp/resources/pdf/all.zip

(History at http://www.peter-cockerell.net/aalp/)

[fredkerr]

Raspberry Pi 3 Model B JTAG and ARMv8 OpenOCD fork:

https://github.com/daniel-k/rpi3-aarch64-jtag
https://github.com/daniel-k/openocd

[Arikania]

This routine divides unsigned integers, and returns both the whole part and the remainder. I believe this to be the fastest routine possible on such processors.

The details are in this post.

Code: Select all

.text
.balign 4
.type udiv, %function
.thumb_func

udiv:
  # r0		the enumerator
  # r1		the denominator


  @ at return:
  # r2		the whole part
  # r3		the remainder


  @ assumptions
  # the denominator is not 0
  # the function does not destroy its arguments or any register above r6


	# init
	movs	r2,#0
	movs	r3,r0

	# determine no. of leading bits in the denominator
	clz	r6,r1

10:	# trap 'division done'
	cmp	r3,r1

	it	lo
	bxlo	lr

	# determine preliminary shift size
	clz	r5,r3
	subs	r4,r6,r5

	# determine preliminary shifted denominator
	lsls	r5,r1,r4

	# adjust shift size and shifted denominator if the shifted denominator outranges the remainder
	cmp	r3,r5

	itt	lo
	sublo	r4,#1
	lsrlo	r5,#1

	# adjust results
	subs	r3,r5

	movs	r5,#1
	lsls	r5,r4
	orrs	r2,r5
	b	10b

This routine, in Thumb-2 code, is tested and verified.

With regards,
Arikania