skiboot v6.0-rc2 release notes

Signed-off-by: Stewart Smith <[email protected]>

Author: stewartsmith

doc/release-notes/skiboot-6.0-rc2.rst

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+.. _skiboot-6.0-rc2:
+
+skiboot-6.0-rc2
+===============
+
+skiboot v6.0-rc2 was released on Wednesday May 9th 2018. It is the second
+release candidate of skiboot 6.0, which will become the new stable release
+of skiboot following the 5.11 release, first released April 6th 2018.
+
+Skiboot 6.0 will mark the basis for op-build v2.0 and will be required for
+POWER9 systems.
+
+skiboot v6.0-rc2 contains all bug fixes as of :ref:`skiboot-5.11`,
+:ref:`skiboot-5.10.5`, and :ref:`skiboot-5.4.9` (the currently maintained
+stable releases). Once 6.0 is released, we do *not* expect any further
+stable releases in the 5.10.x series, nor in the 5.11.x series.
+
+For how the skiboot stable releases work, see :ref:`stable-rules` for details.
+
+The current plan is to cut the final 6.0 in early May (maybe in a day or two
+after this -rc if things look okay), with skiboot 6.0
+being for all POWER8 and POWER9 platforms in op-build v2.0.
+
+Over skiboot-6.0-rc1, we have the following changes:
+
+- Update default stop-state-disable mask to cut only stop11
+
+  Stability improvements in microcode for stop4/stop5 are
+  available in upstream hcode images. Stop4 and stop5 can
+  be safely enabled by default.
+
+  Use ~0xE0000000 to cut all but stop0,1,2 in case there
+  are any issues with stop4/5.
+
+  example: ::
+
+    nvram -p ibm,skiboot --update-config opal-stop-state-disable-mask=0x1FFFFFFF
+
+  **Note**: that DD2.1 chips that have a frequency <1867Mhz possible *need* to
+  run a hcode image *different* than the default in op-build (set
+  `BR2_HCODE_LATEST_VERSION=y` in your config)
+
+- ibm,firmware-versions: add hcode to device tree
+
+  op-build commit 736a08b996e292a449c4996edb264011dfe56a40
+  added hcode to the VERSION partition, let's parse it out
+  and let the user know.
+
+- ipmi: Add BMC firmware version to device tree
+
+  BMC Get device ID command gives BMC firmware version details. Lets add this
+  to device tree. User space tools will use this information to display BMC
+  version details.
+
+- mambo: Enable XER CA32 and OV32 bits on P9
+
+  POWER9 adds 32 bit carry and overflow bits to the XER, but we need to
+  set the relevant CTRL1 bit to enable them.
+
+- Makefile: Fix building natively on ppc64le
+
+  When on ppc64le and CROSS is not set by the environment, make assumes
+  ppc64 and sets a default CROSS. Check for ppc64le as well, so that
+  'make' works out of the box on ppc64le.
+- p9dsu: timeout for variant detection, default to 2uess
+
+- core/direct-controls: improve p9_stop_thread error handling
+
+  p9_stop_thread should fail the operation if it finds the thread was
+  already quiescd. This implies something else is doing direct controls
+  on the thread (e.g., pdbg) or there is some exceptional condition we
+  don't know how to deal with. Proceeding here would cause things to
+  trample on each other, for example the hard lockup watchdog trying to
+  send a sreset to the core while it is stopped for debugging with pdbg
+  will end in tears.
+
+  If p9_stop_thread times out waiting for the thread to quiesce, do
+  not hit it with a core_start direct control, because we don't know
+  what state things are in and doing more things at this point is worse
+  than doing nothing. There is no good recipe described in the workbook
+  to de-assert the core_stop control if it fails to quiesce the thread.
+  After timing out here, the thread may eventually quiesce and get
+  stuck, but that's simpler to debug than undefied behaviour.
+
+- core/direct-controls: fix p9_cont_thread for stopped/inactive threads
+
+  Firstly, p9_cont_thread should check that the thread actually was
+  quiesced before it tries to resume it. Anything could happen if we
+  try this from an arbitrary thread state.
+
+  Then when resuming a quiesced thread that is inactive or stopped (in
+  a stop idle state), we must not send a core_start direct control,
+  clear_maint must be used in these cases.
+- occ: Use major version number while checking the pstate table format
+
+  The minor version increments of the pstate table are backward
+  compatible. The minor version is changed when the pstate table
+  remains same and the existing reserved bytes are used for pointing
+  new data. So use only major version number while parsing the pstate
+  table. This will allow old skiboot to parse the pstate table and
+  handle minor version updates.
+
+- hmi: Clear unknown debug trigger
+
+  On some systems, seeing hangs like this when Linux starts: ::
+
+      [ 170.027252763,5] OCC: All Chip Rdy after 0 ms
+      [ 170.062930145,5] INIT: Starting kernel at 0x20011000, fdt at 0x30ae0530 366247 bytes)
+      [ 171.238270428,5] OPAL: Switch to little-endian OS
+
+  If you look at the in memory skiboot console (or do `nvram -p
+  ibm,skiboot --update-config log-level-driver=7`) we see the console get
+  spammed with: ::
+
+      [ 5209.109790675,7] HMI: Received HMI interrupt: HMER = 0x0000400000000000
+      [ 5209.109792716,7] HMI: Received HMI interrupt: HMER = 0x0000400000000000
+      [ 5209.109794695,7] HMI: Received HMI interrupt: HMER = 0x0000400000000000
+      [ 5209.109796689,7] HMI: Received HMI interrupt: HMER = 0x0000400000000000
+
+  We're taking the debug trigger (bit 17) early on, before the
+  hmi_debug_trigger function in the kernel is set up.
+
+  This clears the HMI in Skiboot and reports to the kernel instead of
+  bringing down the machine.
+
+- core/hmi: assign flags=0 in case nothing set by handle_hmi_exception
+
+  Theoretically we could have returned junk to the OS in this parameter.
+
+- SLW: Fix mambo boot to use stop states
+
+  After commit 35c66b8ce5a2 ("SLW: Move MAMBO simulator checks to
+  slw_init"), mambo boot no longer calls add_cpu_idle_state_properties()
+  and as such we never enable stop states.
+
+  After adding the call back, we get more testing coverage as well
+  as faster mambo SMT boots.
+
+- phb4: Hardware init updates
+
+  CFG Write Request Timeout was incorrectly set to informational and not
+  fatal for both non-CAPI and CAPI, so set it to fatal.  This was a
+  mistake in the specification.  Correcting this fixes a niche bug in
+  escalation (which is necessary on pre-DD2.2) that can cause a checkstop
+  due to a NCU timeout.
+
+  In addition, set the values in the timeout control registers to match.
+  This fixes an extremely rare and unreproducible bug, though the current
+  timings don't make sense since they're higher than the NCU timeout (16)
+  which will checkstop the machine anyway.
+
+- SLW: quieten 'Configuring self-restore' for DARN,NCU_SPEC_BAR and HRMOR
+- Experimental support for building with Clang
+- Improvements to testing and Travis CI