op-build instructions
=====================

Use 'op-build' to build skiboot/skiroot/Petitboot, all that.
There are instructions in the github project's README:
    https://github.com/open-power/op-build/

You can build on x86_64 computer (automatic cross-build)
or on a powerpc64(le) server (baremetal w/ smt8 is fast).

0) build deps (rhel-alt-7.5)

    $ sudo yum -y install gcc-c++ flex bison git ctags cscope expat-devel patch \
      zlib-devel zlib-static texinfo perl-bignum "perl(XML::Simple)" \
      "perl(YAML)" "perl(XML::SAX)" "perl(Fatal)" "perl(Thread::Queue)" \
      "perl(Env)" "perl(XML::LibXML)" "perl(Digest::SHA1)" libxml2-devel \
       which wget unzip tar cpio python bzip2 bc findutils ncurses-devel lzo-devel

1) git clone/setup

    $ git clone https://github.com/open-power/op-build.git
    $ cd op-build

    $ . op-build-env

     that should do it, but it tells to run this and retry:
    $ git submodule init && git submodule update

    $ . op-build-env 

2) find op-build release with desired kernel version (v4.15.14)

The default build config for boston (p9dsu platform) config is p9dsu_defconfig.

    $ git log --oneline origin/master openpower/configs/p9dsu_defconfig | head
    ...
    6453c89 kernel: Move to Linux v4.15.14-openpower1
    ...

Check which release contains that commit.

    $ git describe --contains 6453c89
    v1.22~5^2

And checkout it into a branch:

    $ git checkout -b bz166588 v1.22

The skiroot's kernel version string is the combination of 
the linux stable kernel version in the config:

    $ grep BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE openpower/configs/p9dsu_defconfig
    BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.15.14"

with the 'Release' patch:

    $ grep EXTRAVERSION openpower/linux/000*-Release*.patch
    -EXTRAVERSION =
    +EXTRAVERSION = -openpower1

This is the patch dir, put additional patches here:

    $ ls -1 openpower/linux/
    0001-xhci-Reset-controller-on-xhci-shutdown.patch
    0002-tg3-APE-heartbeat-changes.patch
    0003-powerpc-eeh-Fix-race-with-driver-un-bind.patch
    0004-Release-OpenPower-kernel.patch

    $ cp ~/tlbie-p9-workaround.patch openpower/linux/0005-Fixup-tlbie-vs-store-ordering-on-POWER9.patch

(BACKPORT PATCHES BEGIN)
You can make the backports on top of v4.15.14 in linux-stable or
    https://github.com/open-power/linux/
    e.g., [~/git/linux]$ git checkout -b bz166588 v4.15.14

    loop:
    $ git format-patch -1 --start-number=<N> <commit id>
    $ patch -p1 -F0 --dry-run -i <000N-*.patch>
    $ vim -O 000N*-.patch <src file with conflict> # fix/backport/apply dependency commits/repeat
    $ git am 000N*-.patch

And I ended up with 8 patches:

    $ git log --oneline | head
    f1b17fd scsi: qla2xxx: Fix double free bug after firmware timeout
    6d88b15 scsi: qla2xxx: Prevent relogin trigger from sending too many commands
    d101db7 scsi: qla2xxx: Fix warning in qla2x00_async_iocb_timeout()
    e5a54a1 scsi: qla2xxx: Don't call dma_free_coherent with IRQ disabled.
    d908d0c scsi: qla2xxx: Serialize session free in qlt_free_session_done
    cdea9a7 scsi: qla2xxx: Serialize session deletion by using work_lock
    86ac6a0 scsi: qla2xxx: Remove unused argument from qlt_schedule_sess_for_deletion()
    1600bd6 scsi: qla2xxx: Fix session cleanup for N2N
    0ba3b3a Linux 4.15.14
    9c5ee99 bpf, x64: increase number of passes

    $ mkdir bz166588
    $ git format-patch -8 --start-number 10 -o bz166588  # some number space between op-builds existing patches and this series.
    $ scp -r bz166588 hab4-73:~/
(BACKPORT PATCHES END)

And back to the power system to apply patches/build:

    $ cp ~/bz166588/*.patch openpower/linux/

    $ ls -1 openpower/linux/
    0001-xhci-Reset-controller-on-xhci-shutdown.patch
    0002-tg3-APE-heartbeat-changes.patch
    0003-powerpc-eeh-Fix-race-with-driver-un-bind.patch
    0004-Release-OpenPower-kernel.patch
    0005-Fixup-tlbie-vs-store-ordering-on-POWER9.patch
    0010-scsi-qla2xxx-Fix-session-cleanup-for-N2N.patch
    0011-scsi-qla2xxx-Remove-unused-argument-from-qlt_schedul.patch
    0012-scsi-qla2xxx-Serialize-session-deletion-by-using-wor.patch
    0013-scsi-qla2xxx-Serialize-session-free-in-qlt_free_sess.patch
    0014-scsi-qla2xxx-Don-t-call-dma_free_coherent-with-IRQ-d.patch
    0015-scsi-qla2xxx-Fix-warning-in-qla2x00_async_iocb_timeo.patch
    0016-scsi-qla2xxx-Prevent-relogin-trigger-from-sending-to.patch
    0017-scsi-qla2xxx-Fix-double-free-bug-after-firmware-time.patch

Modify localversion in Release patch

    $ grep EXTRAVERSION openpower/linux/*-Release*.patch
    -EXTRAVERSION =
    +EXTRAVERSION = -openpower1.bz166588c195

Build:

    $ op-build p9dsu_defconfig
    $ op-build menuconfig # enable ccache in Build Options -> Enable Compiler Cache
    $ op-build
    ...
    # Copy the kernel image(s) to its(their) final destination
    /usr/bin/install -m 0644 -D /home/user/op-build/output/build/linux-4.15.14/arch/powerpc/boot/zImage.epapr /home/user/op-build/output/images/zImage.epapr
    ...
    make[1]: *** [/home/user/op-build/output/build/openpower-pnor-dafcab48658b4de48e70c929b036985dac7ef7b8/.stamp_images_installed] Error 2

So it build the kernel successfully (zImage.epapr).
Later it failed on PNOR generation, but that's fine, we don't need it.

Checking the kernel version string:

    $ objdump -h output/images/zImage.epapr | grep vmlinux
     10 .kernel:vmlinux.strip 0181023c  000000002000c000  000000002000c000  0001c000  2**0

    $ dd if=output/images/zImage.epapr of=vmlinux.xz bs=1 skip=$(echo 'ibase=16; 0001C000' | bc) count=$(echo 'ibase=16; 0181023C' | bc)
    25231932+0 records in
    25231932+0 records out
    25231932 bytes (25 MB) copied, 118.849 s, 212 kB/s

    $ xz -dc vmlinux.xz > vmlinux

    $ grep -a 'Linux version' vmlinux
    Linux version 4.15.14-openpower1.bz166588c132 (user@rhel-alt-75.localdomain) (gcc version 6.4.0 (Buildroot 2017.11.2-00008-g4b6188e)) #3 SMP Thu Apr 26 12:26:37 CDT 2018


And you can flash it as described in bug 167103 comment 22
on systems with secure-boot _disabled_ (bug bug 167103 comment 30),
i.e., there is no 'secure-enabled' property in device tree:

    # ls /proc/device-tree/ibm,secureboot/secure-enabled
    ls: cannot access '/proc/device-tree/ibm,secureboot/secure-enabled': No such file or directory

    # lsprop /proc/device-tree/ibm,secureboot/
    compatible       "ibm,secureboot-v2"
    hw-key-hash-size 00000040 (64)
    hw-key-hash      40d487ff 7380ed6a d54775d5 795fea0d
             e2f541fe a9db06b8 466a42a3 20e65f75
             b4866546 0017d907 515dc2a5 f9fc5095
             4d6ee0c9 b67d219d fb708535 1d01d6d1
    phandle          00000086 (134)
    name             "ibm,secureboot"

On Petitboot:

    / # uname -r
    4.13.16-openpower1

    / # wget -O zImage.epapr http://dorno.rch.stglabs.ibm.com/~mauricfo/kernel/skiroot/bz166588/zImage.epapr_4.15.14-openpower1.bz166588c132

    / # pflash -e -p zImage.epapr -P BOOTKERNEL
    About to erase 0x017e1000..0x02ca5478 !
    WARNING ! This will modify your HOST flash chip content !
    Enter "yes" to confirm:yes
    <...>

    / # reboot
    <...>

    EXPECTED:
    / # uname -r
    4.15.14-openpower1.bz166588c132