[U-Boot-Users] mpc8260 serial console works under uboot, but not under linux

jfaslist jfaslist at yahoo.fr
Tue Mar 14 16:28:29 CET 2006

We have ported u-boot on  a mpc8260 based design of ours.
We try to boot linux on it (built with TQM8260_defconfig), as a 
first step. But when we use the u-boot "bootm" command to boot 
linux from flash,  we get nothing displayed after the kernel is 
uncompressed and jumped into. I know there is a FAQ:
But I don't think it applies as using the BDI2000 we can trace 
the kernel running all the way until around the point where it 
starts the init process.
We were surprised to see that a "make uImage" would use the 
vmlinux.gz kernel (linked at 0xc000.0000) and not the 
zImage.elf(linked at 0x0040.0000), which includes the files in 
The serial console is initialized and handled in 
./arch/ppc/boot/simple/m8260_tty.c, and we suspect that since 
this is not included in vmlinux, that is the reason why we don't 
see any messages.
Should we try to somehow add it to vmlinux (if this is possible)?

I know this is not the list, but why is the linux make file is 
generating these two different files? My guess is that zImage is 
for systems with no u-boot bootloader.
Thanks a lot,
-jf simon

[bmc at Linux188 linux-]$ make
   CHK     include/linux/version.h
   CHK     include/linux/compile.h
   CHK     usr/initramfs_list
   UIMAGE  arch/ppc/boot/images/uImage
Image Name:   Linux-
Created:      Tue Mar 14 07:01:49 2006
Image Type:   PowerPC Linux Kernel Image (gzip compressed)
Data Size:    869873 Bytes = 849.49 kB = 0.83 MB
Load Address: 0x00000000
Entry Point:  0x00000000
   Image: arch/ppc/boot/images/uImage is ready
   AS      arch/ppc/boot/simple/head.o
   AS      arch/ppc/boot/simple/relocate.o
   CC      arch/ppc/boot/simple/misc-embedded.o
   CC      arch/ppc/boot/simple/embed_config.o
arch/ppc/boot/simple/embed_config.c:29: warning: 'bdinfo' defined 
but not used
arch/ppc/boot/simple/embed_config.c:415: warning: 'clk_8260' 
defined but not use
arch/ppc/boot/simple/embed_config.c:457: warning: 'clk_8280' 
defined but not use
   CC      arch/ppc/boot/simple/m8260_tty.o
ppc_6xx-objcopy -O elf32-powerpc \
         --add-section=.image=arch/ppc/boot/images/vmlinux.gz \
--set-section-flags=.image=contents,alloc,load,readonly,data \
         arch/ppc/boot/simple/dummy.o arch/ppc/boot/simple/image.o
ppc_6xx-ld -m elf32ppc -T 
/arch/ppc/boot/ld.script -Ttext 0x00400000 -Bstatic -o 
inux arch/ppc/boot/simple/head.o arch/ppc/boot/simple/relocate.o 
imple/misc-embedded.o arch/ppc/boot/simple/embed_config.o 
8260_tty.o arch/ppc/boot/simple/image.o 
arch/ppc/boot/common/lib.a arch/ppc/boot
ppc_6xx-objcopy -O elf32-powerpc arch/ppc/boot/simple/zvmlinux 
ple/zvmlinux -R .comment -R .stab \
         -R .stabstr -R .ramdisk
cp -f arch/ppc/boot/simple/zvmlinux arch/ppc/boot/images/zImage.elf
rm -f arch/ppc/boot/simple/zvmlinux
   Building modules, stage 2.
[bmc at Linux188 linux-]$


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