Re: Booting uncompressed kernel image

[Luotao Fu <l.fu@pengutronix.de>]

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Matteo Fortini wrote:
> Hi all,
> I built an uncompressed uImage using mkimage --no-gzip -C none in the
> wrapper scripts.
> Only, u-boot recognizes it as uncompressed and launches the kernel
> properly (it's around 4MB), but in the end linux just prints
> OK and stops.
Powerpc make compress the bin image with gzip first, before it generates
the image header.  If the u-boot reads the image header properly doesn't
mean that the kernel is really unpacked.
>
> Has anyone done the same?
me ;-) I did it with a mpc5200b board and linux 2.6.23. You can try the
patch attached to this mail. It worked for me[TM]. ;-)

Cheers
Luotao Fu

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Subject: Create an uncomrpessed uImage
From: Luotao Fu <l.fu@pengutronix.de>

This one adds a make target to create an uncomrpessed uImage format for powerpc,
which is usable by uboot. We call the target nuImage for now. We need this to
verify if we can boost up the boot speed.

Signed-off-by: Luotao Fu <l.fu@pengutrnoix.de>

---
 arch/powerpc/Makefile      |    2 +-
 arch/powerpc/boot/Makefile |    3 +++
 arch/powerpc/boot/wrapper  |   15 ++++++++++++++-
 3 files changed, 18 insertions(+), 2 deletions(-)

Index: arch/powerpc/boot/wrapper
===================================================================
--- arch/powerpc/boot/wrapper.orig
+++ arch/powerpc/boot/wrapper
@@ -133,7 +133,7 @@ coff)
     platformo=$object/of.o
     lds=$object/zImage.coff.lds
     ;;
-miboot|uboot)
+miboot|uboot|decuboot)
     # miboot and U-boot want just the bare bits, not an ELF binary
     ext=bin
     objflags="-O binary"
@@ -190,6 +190,19 @@ uboot)
     fi
     exit 0
     ;;
+decuboot)
+    rm -f "$ofile"
+    vmz_uncomp=`basename $vmz $gzip`
+    gunzip -c $vmz > $vmz_uncomp
+    mkimage -A ppc -O linux -T kernel -C none -a 00000000 -e 00000000 \
+	$uboot_version -d "$vmz_uncomp" "$ofile"
+    rm $vmz_uncomp
+    vmz="$vmz$gzip"
+    if [ -z "$cacheit" ]; then
+	rm -f "$vmz"
+    fi
+    exit 0
+    ;;
 esac
 
 addsec() {
Index: arch/powerpc/boot/Makefile
===================================================================
--- arch/powerpc/boot/Makefile.orig
+++ arch/powerpc/boot/Makefile
@@ -195,6 +195,9 @@ $(obj)/zImage.initrd.ps3: vmlinux  $(wra
 $(obj)/uImage: vmlinux $(wrapperbits)
 	$(call if_changed,wrap,uboot)
 
+$(obj)/nuImage: vmlinux $(wrapperbits)
+	$(call if_changed,wrap,decuboot)
+
 $(obj)/cuImage.%: vmlinux $(dts) $(wrapperbits)
 	$(call if_changed,wrap,cuboot-$*,$(dts))
 
Index: arch/powerpc/Makefile
===================================================================
--- arch/powerpc/Makefile.orig
+++ arch/powerpc/Makefile
@@ -148,7 +148,7 @@ all: $(KBUILD_IMAGE)
 
 CPPFLAGS_vmlinux.lds	:= -Upowerpc
 
-BOOT_TARGETS = zImage zImage.initrd uImage
+BOOT_TARGETS = zImage zImage.initrd uImage nuImage
 
 PHONY += $(BOOT_TARGETS)