[RFC 5/5] doc: describe Milk-V Mars board

[Heinrich Schuchardt]

On 3/8/24 00:20, E Shattow wrote:
> 
> On Sun, Mar 3, 2024 at 5:02 AM Heinrich Schuchardt 
> <heinrich.schuchardt at canonical.com 
> <mailto:heinrich.schuchardt at canonical.com>> wrote:
> ...
> 
>     +The board provides the DIP switches MSEL[1:0] to select the boot
>     device out of
>     +SPI flash, eMMC, SD-card, UART. To select booting from SD-card set
>     the DIP
>     +switches MSEL[1:0] to 10.
> 
> 
> This does not match the [Milk-V Mars vendor 
> documentation](https://milkv.io/docs/mars/getting-started/bootloader 
> <https://milkv.io/docs/mars/getting-started/bootloader>). Maybe you have 
> a different board revision?

Thank you for reviewing.

My board revision is V1.21 according to the silk screen.

The Milk-V Mars has DIP switches for the boot selection as shown in
https://gist.github.com/xypron/e28f95b1ed6911aeb9699ba63ae1a885

If you look at the photo 
https://milkv.io/assets/images/mars-icon-04-e8814f18158a0e9d4387f4fa330693f1.webp 
in the https://milkv.io/mars page, it also shows DIP switches (in the 
SPI-Flash position) on a rev 1.2 board.

Did you see a board without DIP switches being sold?

The silk screen markings on the board and the switch don't match.
The same confusion exists on the VisionFive2.

So maybe I should better write in a table:

SPI-Flash:
GPIO0=L
GPIO1=L

SD-Card:
GPIO0=H
GPIO1=L

eMMC:
GPIO0=L
GPIO1=H

UART:
GPIO0=H
GPIO1=H

Best regards

Heinrich