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19.0 19.0 17.0 1.6 MB

Software bootloader for boards running Tock.

Makefile 0.54% C 95.08% Assembly 0.01% Rust 4.33% Shell 0.05%

bootloader tock

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shaneleonard lab11 jon duzhanyuan benjione krady21 wyliodrinembeddediot mfkiwl icodein mdclyburn isabella232 zh30 halfborg qpc-github placrosse gentooza

tock-bootloader's Issues

tock-bootloader requires a different rust nightly than tock

Not a great deal, but slightly annoying.

Bootloader cannot update itself

Although the bootloader can program the kernel and any application over serial, it cannot update its own code, since it is running from flash.

If the bootloader code relocates into RAM, it would be possible to arbitrarily overwrite its flash image. Thus, the bootloader could update itself.

I think the relocation step could be implemented simply by changing the linker script, so that all code sections are between _srelocate and _erelocate. The startup code will take care of the rest.

The only remaining item would be to add a corresponding command to tockloader.

Maybe this is a feature we don't actually want? It would allow a board to be bricked by a bad bootloader image (assuming the developer doesn't have a JLink). For a developer with only serial port access, the choice is either 1. a bad bootloader update could brick them, or 2. they are stuck with whatever version of the bootloader they started with.

Personally, I think 2. is the worse case, but maybe others feel differently. Thoughts?

Did mcuboot considered as base or reference?

I saw this project and the mcuboot[1] project came to my mind as a good reference to be used as a base or design reference.

https://github.com/linaro-technologies/mcuboot

I thought it would be great to raise it now as the project is active and this can shorten the amount of effort need to add OTA and safe upgrade support.

no port for risc-v

Is there some plan support for port risc-v ?

nrf52dk bootloader

What is necessary to use the bootloader with the nrf52dk USB debugger?

Support "USB-only" nRF52 boards

Typically our bootloaders require an FTDI chip to do serial over USB so that the bootloader running on the chip only requires a serial interface. Since MCUs sometimes have USB hardware, It has always seemed reasonable to omit the FTDI chip and just communicate with the USB peripheral on the MCU directly. In particular, the Arduino Nano 33 relies on having a USB bootloader on the chip itself.

Help Wanted: Make kernel location variable

Right now, the kernel location is fixed at 0x10000. Ideally, this wouldn't be fixed in case a platform wants to put its kernel at a different address.

tock-bootloader/bootloader/src/bootloader.rs

Lines 143 to 157 in 8228baf

 fn jump(&self) { 

 unsafe { 

 asm!( 

 ".syntax unified \n\ 

  ldr r0, =0x10000 // The address of the payload's .vectors \n\ 

  ldr r1, =0xe000ed08 // The address of the VTOR register (0xE000E000(SCS) + 0xD00(SCB) + 0x8(VTOR)) \n\ 

  str r0, [r1] // Move the payload's VT address into the VTOR register \n\ 

  ldr r1, [r0] // Move the payload's initial SP into r1 \n\ 

  mov sp, r1 // Set our SP to that \n\ 

  ldr r0, [r0, #4] // Load the payload's ENTRY into r0 \n\ 

  bx r0 // Whoopee" 

 ); 

 } 

 } 

 }

I don't think this would be particularly hard, I just don't know how to do it.

but the only subdirectory is

boards/hail-bootloader

Does this work for imix? If hail is the only board supported then the instructions should say so explicitly.

	fn jump(&self) {
	unsafe {
	asm!(
	".syntax unified \n\
	ldr r0, =0x10000 // The address of the payload's .vectors \n\
	ldr r1, =0xe000ed08 // The address of the VTOR register (0xE000E000(SCS) + 0xD00(SCB) + 0x8(VTOR)) \n\
	str r0, [r1] // Move the payload's VT address into the VTOR register \n\
	ldr r1, [r0] // Move the payload's initial SP into r1 \n\
	mov sp, r1 // Set our SP to that \n\
	ldr r0, [r0, #4] // Load the payload's ENTRY into r0 \n\
	bx r0 // Whoopee"
	);
	}
	}
	}