<!DOCTYPE html><html><body><div dir="auto">Hello everyone,<br><br><br>I am in need of some friendly advice. I am working on getting an application running, which I compiled for PowerPC using the qoriq_e500 BSP (<a href="https://docs.rtems.org/branches/master/user/bsps/bsps-powerpc.html#qoriq-qoriq">https://docs.rtems.org/branches/master/user/bsps/bsps-powerpc.html#qoriq-qoriq</a>).<br><br>Due to the current lack of a physical board, I want to have it run in QEMU on the ppce500 machine (<a href="https://www.qemu.org/docs/master/system/ppc/ppce500.html">https://www.qemu.org/docs/master/system/ppc/ppce500.html</a>).<br><br>I have RTEMS on head 25ba67963aa23dff4fbe87a2e0c56b8c011cdf8a and set everything up via the source builder at head 423d98d2058a7dac0921f9a13113b024696236b9 (so my state is from early June).<br><br> <br><br>I have created the application image und started it up inside QEMU via the U-Boot bootloader.<br><br>However, my application runs into a fatal error (QORIQ_FATAL_FDT_NO_BUS_FREQUENCY) early on, and then gets stuck trying to print (what I assume is) an error message (see the following stack trace):<br><br> <br><br>```<br><br>(gdb) bt<br><br>#0 ns16550_polled_putchar (base=0x2001148 <qoriq_uart_context_0>, out=13 '\r')<br><br> at ../../../bsps/shared/dev/serial/ns16550-context.c:535<br><br>#1 0x0004f1e0 in rtems_putc (c=10 '\n') at ../../../cpukit/libcsupport/src/rtems_putc.c:49<br><br>#2 0x0004d264 in _IO_Vprintf (put_char=0x4f1a8 <rtems_put_char>, arg=arg@entry=0x0, fmt=0x1004311 "%s\n",<br><br> fmt@entry=0x1004310 "\n%s\n", ap=ap@entry=0x2389e80 <_ISR_Stack_area_begin+7872>) at ../../../cpukit/dev/iovprintf.c:133<br><br>#3 0x00044e44 in vprintk (fmt=fmt@entry=0x1004310 "\n%s\n", ap=ap@entry=0x2389e80 <_ISR_Stack_area_begin+7872>)<br><br> at ../../../cpukit/libcsupport/src/vprintk.c:45<br><br>#4 0x00040df4 in printk (fmt=fmt@entry=0x1004310 "\n%s\n") at ../../../cpukit/libcsupport/src/printk.c:41<br><br>#5 0x0003d410 in bsp_fatal_extension (source=RTEMS_FATAL_SOURCE_BSP, always_set_to_false=<optimized out>, code=2561)<br><br> at ../../../bsps/shared/start/bspfatal-default.c:66<br><br>#6 0x0004cc90 in _User_extensions_Iterate (arg=arg@entry=0x2389f48 <_ISR_Stack_area_begin+8072>,<br><br> visitor=0x4cb88 <_User_extensions_Fatal_visitor>, direction=direction@entry=CHAIN_ITERATOR_FORWARD)<br><br> at ../../../cpukit/score/src/userextiterate.c:194<br><br>#7 0x0004889c in _User_extensions_Fatal (error=2561, source=RTEMS_FATAL_SOURCE_BSP)<br><br> at ../../../cpukit/include/rtems/score/userextimpl.h:467<br><br>#8 _Terminate (the_source=the_source@entry=RTEMS_FATAL_SOURCE_BSP, the_error=the_error@entry=2561)<br><br> at ../../../cpukit/score/src/interr.c:55<br><br>#9 0x0003d0b8 in rtems_fatal (fatal_code=2561, fatal_source=RTEMS_FATAL_SOURCE_BSP) at ../../../cpukit/include/rtems/fatal.h:160<br><br>#10 bsp_fatal (code=QORIQ_FATAL_FDT_NO_BUS_FREQUENCY) at ../../../bsps/include/bsp/fatal.h:222<br><br>#11 initialize_frequency_parameters () at ../../../bsps/powerpc/qoriq/start/bspstart.c:89<br><br>#12 bsp_start () at ../../../bsps/powerpc/qoriq/start/bspstart.c:178<br><br>#13 0x00047808 in rtems_initialize_executive () at ../../../cpukit/sapi/src/exinit.c:135<br><br>#14 0x0003c68c in boot_card (cmdline=<optimized out>) at ../../../bsps/shared/start/bootca<br><br>#15 0x0000412c in bsp_section_start_begin () at ../../../bsps/powerpc/qoriq/start/start.S:<br><br>```<br><br> <br><br>I suspect that the flattened device tree is not being loaded correctly, which also leads to the application not being able to push out characters to UART.<br><br> <br><br>Further investigation went as follows:<br><br>During initialize_frequency_parameters() in bsps/powerpc/qoriq/start/bspstart.c (<a href="https://gitlab.rtems.org/rtems/rtos/rtems/-/blob/main/bsps/powerpc/qoriq/start/bspstart.c),">https://gitlab.rtems.org/rtems/rtos/rtems/-/blob/main/bsps/powerpc/qoriq/start/bspstart.c),</a> the first call to fdt_node_offset_by_prop_value() returns the negative node integer -9, which, if I traced everything correctly, means I have run into the error FDT_ERR_BADMAGIC, telling me I don't have a real device tree present at all.<br><br>I then went a step back and followed the flow of initialize_frequency_parameters() from the beginning, ending up in bsp_fdt_get() of bsps/shared/start/bsp-fdt.c (<a href="https://gitlab.rtems.org/rtems/rtos/rtems/-/blob/main/bsps/shared/start/bsp-fdt.c">https://gitlab.rtems.org/rtems/rtos/rtems/-/blob/main/bsps/shared/start/bsp-fdt.c</a>).<br><br>At this point I found out that BSP_DTB_IS_SUPPORTED is not defined, as only the array bp_fdt_blob exists and is accessed. This array is filled with the pre-initialized `0xdeadbeef` values and does not contain any meaningful data.<br><br> <br><br>My question is:<br><br>I fail to see the mechanism by which a real FDT should have been available at this point. Is there a detail or some magic that I am missing here that would make this work usually? I could not find any trace of any linker scripts or any routines that are used to add content to the blob/array.<br><br><br>Kind Regards,<br><br>Daniel</div></body></html>