Hi Everyone, Recently I took up the activity of switching from Linux kernel version 2.16.17.6 to version 4.15.13 for our target board that supports MPC8270 PowerPC processor. As I understand the new kernel version mandates the use of a device tree in the kernel source to describe the target board. I took "pq2fads.dts" as a reference device tree file to port the kernel for our target board. The U-boot version 1.1.4 that we currently use does not support passing of device tree to kernel but passes the board information structure used by the older kernel version we have been using so far.
As suggested in the new kernel documentation I created a "cuImage.pq2fads" kernel image which has the device tree and boot wrapper code embedded in the image to support booting the kernel with older U-boot. However I am unable to see any debug output after the dump from U-boot below. U-Boot 1.1.4 (Aug 2 2018 - 06:27:35) MPC8260 Reset Status: Check Stop, External Soft, External Hard MPC8260 Clock Configuration - Bus-to-Core Mult 4x, VCO Div 2, 60x Bus Freq 25-75 , Core Freq 100-300 - dfbrg 1, corecnf 0x1a, busdf 5, cpmdf 1, plldf 0, pllmf 5 - vco_out 394515000, scc_clk 98628750, brg_clk 24657187 - cpu_clk 263010000, cpm_clk 197257500, bus_clk 65752500 CPU: MPC8260 (HiP7 Rev 14, Mask 1.0 1K49M) at 263.010 MHz Board: Emerson MPC8270 CCB Init SRAM, CAN, DOC... UPMA done. Setting up UPMB Rev B or Higher CPU Board I2C: ready DRAM: 128 MB FLASH: 16 MB In: serial Out: serial Err: serial Net: FCC1 ETHERNET, FCC2 ETHERNET Press <foo> to STOP AUTOBOOT!:autoboot in 2 seconds ## Booting image at ffc00000 ... Image Name: Linux-4.15.13 Created: 2018-08-29 10:45:39 UTC Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 1166748 Bytes = 1.1 MB Load Address: 00400000 Entry Point: 004007a4 Verifying Checksum ... OK Uncompressing Kernel Image ... OK I also checked the kernel dump at location associated with "_log_buf" symbol in the System.map file in RAM but did not get any debug info. Please can anyone suggest if I am missing something here and how can I get the debug output on my serial console during bootup. Thanks, Sachin. -- Sent from: http://linuxppc.10917.n7.nabble.com/linuxppc-dev-f3.html
