10-10-2019, 12:51 PM
(10-09-2019, 03:39 PM)z4v4l Wrote: I think, the first thing, that needs to be clarified is distinguishing between the ROM code boot ordering and uboot ordering and therefore - between where uboot could be placed and where OS could. the term "hardcoded" is confusing, basically it makes sense only if it refers to the ROM code, - the only "hardcoded" thing in this chain. its boot ordering is given in the rk3399 manual and I posted it above.
I agree that makes sense, so the Wiki should be re-written. Although, given conflicting information, I'll wait to give others a chance to post additions and corrections here.
(10-08-2019, 05:45 PM)z4v4l Wrote: Just for clarification. rk3399 ROM code boot order is this:
1. SPI NOR
2. SPI NAND
3. eMMC
4. SD
5. USB OTG*
* - USB is used not as mass storage device interface, so sticks can't be used, but as an interface for remote downloading the payload through a rockchip custom protocol.
The datasheet listing for components only lists SPI NOR. Is there a SPI NAND installed on the PBP? If not, then the hardcoded ROM boot order for the PBP is: SPI NOR, eMMC, SD, USB OTG. Correct?
Currently, the Wiki states "This boot order is different then the default hard-coded boot order of the SoC: SPI, eMMC, USB 2.0, USB 3.0, SD card" which lists USB before SD.
(10-09-2019, 03:39 PM)z4v4l Wrote: it's important to distinguish for everybody to get it (finally). so, you need to have uboot at one of those and only those interfaces to get booting happen. and the order will be that and can't be changed. the next thing is clarifying of what uboot can boot (the OS) from. here, the order is not as important since you can change it, in boot.scr or whatever uboot script/commands. so, the answer from where uboot can boot the OS is those interfaces, that are supported by the provided uboot version. as I understand, it can do USB but can't PCIe. and the orders currently mentioned in the wiki most probably refer to the way uboot scripts/boot commamds are currently configured (however I think it's a mix of that and the ROM code order, because I doubt uboot will search linux on SPI).
So to clarify, in order to work, uboot can only be placed on the devices listed in the above ROM code boot order?
This leads me to believe that "At this time, the boot order for the custom uboot (on eMMC) on the default Debian + MATE build is: SD, USB 2.0, eMMC" means the SPI firmware is flashed to point to uboot on the eMMC. Is that correct? Then uboot on the eMMC looks for an OS on the SD, then USB 2.0, then eMMC?