upx --lzma compresses much tighter than gzip. A user-mode test jig succesfully handles the 2.6.21.1 kernel configured with defconfig-minimal in 1,018,237 bytes total, in contrast to the 1,390,765 bytes of vmlinux.bin.gz (and the .gz does not include 34,795 bytes for compiled arch/powerpc/boot/*.c.) However, I cannot figure out how to get a real bootable kernel that uses compression. I'd like to test it on an Apple PowerMac G4 that now runs Fedora Core 6. The FC6 kernel calls itself "vmlinuz" but does _not_ use any compression; I double-checked by rebuilding from the .src.rpm.
A plain "make" in a kernel.org-2.6.21.1 tree gives a vmlinux that is not compressed. A "make zImage" produces arch/powerpc/boot/uImage [with no thanks to the *undocumented* mkimage] that uses gzip, but does not use any code from arch/powerpc/boot/*.c; so where is the decompression code? linux/Documentation/powerpc/*.txt does not shed light on these issues. Please point me at a description of the flow of control for building and booting a compressed Linux kernel for powerpc. Thank you. -- _______________________________________________ Linuxppc-embedded mailing list [email protected] https://ozlabs.org/mailman/listinfo/linuxppc-embedded
