From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Date: Mon, 23 Nov 2020 21:18:49 +0200 Subject: early stage debugging on a real product In-Reply-To: References: Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Mon, Nov 23, 2020 at 9:08 PM Simon Glass wrote: > On Mon, 23 Nov 2020 at 07:04, Andy Shevchenko wrote: Thanks! My comments below. > > I have been debugging U-Boot on a product (Android-based) device (*) > > which is not yet supported by U-Boot. It's x86 based. > > > > I have stumbled over the couple of things: > > 1/ it required me to enable TIMER_EARLY and by code analysing I can > > tell that DM loop fails by some reason > > 2/ it hangs > > reserve_uboot, > > reserve_malloc, > > reserve_board, > > ...here... > > > > My suspicion that fastboot does bad things to it (overwritten memory) > > or something I have missed. Any ideas what to try / where to look into > > besides the above which I'm on? > > #define DEBUG at the top of board_f.c - you might need DEBUG_UART > > Make sure that start.S puts the top of memory in a sensible place. If > something has set up RAM already then you probably want it to be the > top of RAM, below 2GB. I wasn't clear, there is no means to debug (See * below). There is no output except vibra, perhaps I may have (charger) led, but former I got working, maybe I need to implement morse code. > > (*) Only I can get is just an approximate place where the code is > > stuck / hangs. And it's time consuming... > > > > Use a Dediprog SPI emulator and an Intel debugger. Not sure how it is possible... The only connector I have is micro-B. -- With Best Regards, Andy Shevchenko