imx233 bootlets and no battery board

[mlopez]

The default configuration of the bootlet code for the latest i.MX233 support a hardware configuration that has both a LiIon battery configuration. For other configurations though such as a VDD5V connection only or a DCDC_BATT/Battery connection only, some additional changes need to be done.

I'm designing a board with the i.M233 and VDD5V connection with no battery.

What are the additional changes in boot_prep recommended to work this way?

The bootloader also checks the adc to decide which load chain use, based on pressed keys. How could I disable this feature?

Could anyone help me?

Thanks

[JorgeRama_rezRi]

Hi,

I'm not much a SW guy, but I'd like to point there are some details you need to take into account on the HW side. Please take a look to page 4 of the attached for connections for 5V operation.

Best regards.

Jorge.

[mlopez · Accepted solution]

Thank you.

I've not seen the revc schematics till now (only revb).

My problem was that in my board, the DC_DC_BAT and BATT pins were not connected.

By placing a 1K pull-up resistor to 4.2V and a 33uF capacitor to ground to both pins connected together, all starts OK without any change in software.

[OtavioSalvador]

You may want to look at U-Boot as it has got MX233 support; the code is much easier to follow and hack than bootlets.

The first version with support for MX233 will be 2013.04 but current GIT has it already; other fixes and improvements (as USB support) has been posted today in mailing list.

[VladanJovanovic]

There's some patches for i.MX28 available for this kind of setup. As it's quite similar to i.MX233, it may provide some guidelines on how to do this.

i.MX287 Product Summary Page