Re: [U-Boot] FDT: Question about embedded fdt enable

30 May 2012

      Hi Donghwa,
On Wed, May 30, 2012 at 12:37 AM, Donghwa Lee dh09.lee@samsung.com wrote:
...
On Wed, May 23, 2012 at 15:13, Simon Glass wrote:
...
HI Donghwa,
On Wed, May 23, 2012 at 12:39 AM, Donghwa Lee <dh09.lee@samsung.com<mailto:
dh09.lee@samsung.com>> wrote:
...
Dear, Simon Glass

I am preparing device tree in Exynos SoC and had already tested by

using
...
CONFIG_OF_SEPARATE. But, I couldn't test by using CONFIG_OF_EMBED

because
...
it has a compiler problem to make a binary in the dts/Makefile.

When I had used configuration as seaboard that I had changed

configuration
...
from CONFIG_OF_SEPARATE to CONFIG_OF_EMBED, it had a same problem.

How did you test in seaboard as it embedded? Is there any more

configuration
...
to compile ebedded option?

Can you please send me the compiler output - then I can help with this.
I do use embedded for testing only. But there is an alignment patch
which is needed and was NAKed. So it is not reliable at present.
...
please reply my question.

Thank you,
Donghwa Lee

Regards,
Simon
Dear, Simon Glass
Thank you for your reply. Below log is my compiler problem that was
stopped while objcopy.
# We want the output format and arch.
# We also hope to win a prize for ugliest Makefile / shell interaction
# We look in the LDSCRIPT first.
# Then try the linker which should give us the answer.
# Then check it worked.
oformat=`cat  | sed -r -n 's/^OUTPUT_FORMAT[ ("]*([^")]*).*/\1/p'` ;\
       oarch=`cat  | sed -r -n 's/^OUTPUT_ARCH[ ("]*([^")]*).*/\1/p'` ;\
       \
       [ -z ${oformat} ] && \
oformat=`/opt/tools/gcc-linaro-arm-linux-gnueabi-2012.04-20120426_linux/bin/arm-linux-gnueabi-gcc
-g  -Os   -fno-common -ffixed-r8 -msoft-float  -D__KERNEL__
-DCONFIG_SYS_TEXT_BASE=0x63300000
-I/home/leedonghwa/project/mainline/u-boot-trats/include -fno-builtin
-ffreestanding -nostdinc -isystem
/opt/tools/gcc-linaro-arm-linux-gnueabi-2012.04-20120426_linux/bin/../lib/gcc/arm-linux-gnueabi/4.7.1/include
-pipe  -DCONFIG_ARM -D__ARM__ -marm -mabi=aapcs-linux -mno-thumb-interwork
-march=armv5 -Wall -Wstrict-prototypes -fno-stack-protector
-Wno-format-nonliteral -Wno-format-security -fstack-usage  -Wl,--verbose
2>&1 | sed -r -n 's/^OUTPUT_FORMAT[ ("]*([^")]*).*/\1/p'` ;\
       [ -z ${oarch} ] && \
oarch=`/opt/tools/gcc-linaro-arm-linux-gnueabi-2012.04-20120426_linux/bin/arm-linux-gnueabi-gcc
-g  -Os   -fno-common -ffixed-r8 -msoft-float  -D__KERNEL__
-DCONFIG_SYS_TEXT_BASE=0x63300000
-I/home/leedonghwa/project/mainline/u-boot-trats/include -fno-builtin
-ffreestanding -nostdinc -isystem
/opt/tools/gcc-linaro-arm-linux-gnueabi-2012.04-20120426_linux/bin/../lib/gcc/arm-linux-gnueabi/4.7.1/include
-pipe  -DCONFIG_ARM -D__ARM__ -marm -mabi=aapcs-linux -mno-thumb-interwork
-march=armv5 -Wall -Wstrict-prototypes -fno-stack-protector
-Wno-format-nonliteral -Wno-format-security -fstack-usage  -Wl,--verbose
2>&1 | sed -r -n 's/^OUTPUT_ARCH[ ("]*([^")]*).*/\1/p'` ;\
       \
       [ -z ${oformat} ] && \
               echo "Cannot read OUTPUT_FORMAT from lds file " && \
               exit 1 || true ;\
       [ -z ${oarch} ] && \
               echo "Cannot read OUTPUT_ARCH from lds file " && \
               exit 1 || true ;\
       \
       cd ./ && \
/opt/tools/gcc-linaro-arm-linux-gnueabi-2012.04-20120426_linux/bin/arm-linux-gnueabi-objcopy
-I binary -O ${oformat} -B ${oarch} \
               dt.dtb dt.o
I don't actually see any output here, or any error. What is going wrong,
please?
...
And I have one more question about passing *.dtb to kernel.
I had make a .dtb binary by using CONFIG_OF_SEPARATE and confirmed
normally working in u-boot.
When kernel is booting, how could kernel access .dtb binary?
Could kernel access dtb binary by setting /memreserve/ in u-boot .dts file
or by using "fdtaddrcontrol"
environment variable in u-boot board file?
But, by my result, dt_phys address in setup_machine_fdt() in
arch/arm/devtree.c had always indicated only
one point regardless of /memreserve/ or fdtcontroladdr.
Please be very careful - this is a completely separate FDT. The use of
CONFIG_OF_CONTROL is for U-Boot's internal configuration only. The same FDT
should not be passed to Linux in the normal case. Please continue to use
the existing FDT support for passing a .dtb file to the kernel.
So you have an FDT for U-Boot which is available via CONFIG_OF_SEPARATE,
and an FDT which U-Boot passes to the kernel, which is read using the
normal uImage/Fit image method.
Regards,
Simon
...
Thank you,
Donghwa Lee