port Zephyr-based runtime.io bootloader to x86 for OTA updates

[nashif]

Reported by Andrew Boie:

We would like to be able to use runtime.io's loader for OTA updates. Demonstrate this up and running on an x86 board like Arduino 101.

(Imported from Jira ZEP-1792)

[nashif]

by punit vara:

Can you please share link to source code of runtime.io bootlaoder ? I tried to search but didnt get.

[nashif]

by Andrew Boie:

punit vara

The github repo is at https://github.com/runtimeco/mcuboot .

JIRA tracking is at https://runtimeco.atlassian.net/projects/MCUB

[nashif]

by punit vara:

Thanks Andrew Boie . Any pointer how should I start this process ?

[nashif]

by Andrew Boie:

punit vara this issue is assigned to me and I've started to look into it this week. Do you want to take over this task? I'm confused.

[nashif]

by Andrew Boie:

For simplicity's sake, the initial proof-of-concept will use an adjusted flash map for Arduino 101, and position the mcuboot loader as a 3rd-stage bootloader. This is so we don't disturb the stock Arduino 101 boot roms which can be a pain to restore.

Memory map for this experiment:

Boot ROM: 0xFFFFE000 - 0xFFFFFFFF 1st stage loader (stock) (x86 reset vector at 0xFFFFFFF0h)

Flash: (two banks of 192KB starting at 0x40000000) 0x40000000 - 0x4000FFFF 2nd stage loader (stock) 0x40010000 - 0x4001FFFF 3rd stage loader (MCUBoot x86) - entry 0x40010030 0x40020000 - 0x4002FFFF Primary slot - entry 0x40020000 0x40030000 - 0x4003FFFF Secondary slot 0x40040000 - 0x4004FFFF Scratch area

Again, this is just a simplified layout for experimentation purposes. We will leave the ARC side completely disabled for this demo.

[nashif]

by punit vara:

Andrew Boie Nope. You can go on. I have started working on other JIRA.

[nashif]

by Andrew Boie:

https://github.com/runtimeco/mcuboot/pull/24

[nashif]

by David Brown:

Add pull request as link.