Hi Jon, please use bottom posting [1] I've added our am335x based board (Baltos iR5221 etc.) recently [2]. On Thu, Dec 8, 2016 at 11:04 PM, Jonathan Stackhouse <jon@xxxxxxxxx> wrote: > Hello Ian, > > Thank you for your kind reply. > > I've modified all of the files that you've listed. > > My next couple of questions are aimed at anyone in the community who may > know their answers. > Does the MLO/PBL depend on the device tree in order to do the low-level > initialization? I'm assuming that it does since the lowlevel.c for the > beaglebone contains the line "fdt = __dtb_z_am335x_bone_common_start;", but > I don't know. If it does, to what extent does it depend upon the device > tree? The hardware part will be configured soleily via DTS. See my minimal DTS file [3]. Just take your DTS file that you use in kernel and throw everything you don't really need at boot time. > Do I need to have a "working" device tree before I can use barebox? My hope > was that I could get barebox up and running first, then build and test the > device tree (although I have already been working on one). No idea. But using DTS is very convenient. Especially if you already have a working Linux version of it. > Are there any other pointers that anyone can offer me? [1] https://en.wikipedia.org/wiki/Posting_style#Bottom-posting [2] https://git.pengutronix.de/cgit/barebox/commit/?id=aadf261cd6932918dede79add72953fd56df2996 [3] https://git.pengutronix.de/cgit/barebox/tree/arch/arm/dts/am335x-baltos-minimal.dts?id=aadf261cd6932918dede79add72953fd56df2996 Yegor > -----Original Message----- > From: Ian Abbott [mailto:abbotti@xxxxxxxxx] > Sent: Thursday, December 08, 2016 5:11 AM > To: Jonathan Stackhouse <jon@xxxxxxxxx>; barebox@xxxxxxxxxxxxxxxxxxx > Subject: Re: AM335x Porting Questions > > On 07/12/16 23:01, Jonathan Stackhouse wrote: >> Hello Barebox Community! >> >> I'm attempting to port the Beaglebone board files >> (arch/arm/boards/beaglebone) to another similar board, but am having a >> bit of a hard time understanding what all I need to do. >> >> Is there a specific procedure that I should follow when porting >> barebox or is it merely making changes/additions to the files in >> arch/{ARCH}/boards/some-similar-board? I've read though the README in >> the barebox root directory as well as several of the docs in the >> Documentation folder and the online user manual but have not found the >> information I am looking for. > > Having done something similar recently (but on socfpga, not am335x), the > directories/files in question are: > > arch/${ARCH}/boards/Makefile > arch/${ARCH}/boards/YOUR-BOARD/* (most of your source code here) > arch/${ARCH}/mach-SOMETHING/Kconfig (or arch/${ARCH}/Kconfig for some > ${ARCH}s) > arch/${ARCH}/configs/YOUR-BOARD_defconfig (optional) > arch/${ARCH}/configs/YOUR-BOARD-xload_defconfig (optional) > arch/${ARCH}/dts/Makefile (if ${ARCH} uses device-tree) > arch/${ARCH}/dts/DTS-FOR-YOUR-BOARD.dts (if $(ARCH} uses device-tree) > arch/${ARCH}/dts/OTHER-COMMON-DTS-STUFF.dtsi (optional, as required) > images/Makefile.PICK-OR-CREATE-ONE > images/Makefile (if you created a new images/Makefile.*) > > You don't need the defconfig files if you only manage the configuration > outside of barebox, unless the board is to be merged back into barebox > upstream. > >> Do the SPL/MLO and barebox.bin write any data to log files for >> debugging purposes? If so, how do I configure the builds for these >> logs and how do I access them? I'm asking because I noticed under >> Debugging in menuconfig that I can set the "default loglevel" but I >> don't know where the log gets stored, and I wanted to view it to see > whether my MLO is working or not. > > Logs go to the console, which is usually a serial port or a frame buffer. > >> Additionally, I've attempted to get the MLO to initialize UART0 and >> UART2 for debugging purposes, but can't seem to get the "MLO>" prompt >> to appear in PuTTY (settings are 115200, 8N1, no flow control). I have >> console support set to "full", Console activation strategy set to >> "activate first console on startup", low level debug messages enabled, >> and the OMAP Debug UART Port Selection set to 2. I also used the same >> UART initialization code that is in the beaglebone lowlevel.c file, >> with the exception that I set it up for >> UART2 instead of UART0. What else I need to do? > > You might need to set the default baudrate to 115200 under "General Settings > --> Default baudrate" in the barebox configurations for MLO and final-stage > bootloader. > > You may also need to do some work on your .dts files to mark &uart2 status > as "okay" and set up the pin muxing for uart2. > >> I apologize for this rather broad and long email, but I've been >> battling this for quite some time and have finally decided to reach out > for help. > > Good luck! I've never actually used barebox on any AM335x based boards > (though I tinkered with u-boot a couple of years ago), and am a bit of a > noob with barebox myself. > > -- > -=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@xxxxxxxxx> )=- > -=( Web: http://www.mev.co.uk/ )=- > > > _______________________________________________ > barebox mailing list > barebox@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/barebox _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
