xref: /aosp_15_r20/external/coreboot/Documentation/releases/coreboot-4.20.1-relnotes.md (revision b9411a12aaaa7e1e6a6fb7c5e057f44ee179a49c)
1coreboot 4.20 release
2========================================================================
3
4The 4.20 release was done on May 15, 2023. Unfortunately, a licensing
5issues was found immediately after the release was completed, and it
6was decided to hold the release until that was fixed.
7
8Please do not use the 4.20 tag, and use the 4.20.1 git tag instead. The
94.20_branch will contain all code for 4.20, 4.20.1, and any further
10changes required for this release.
11
12The coreboot community has done a tremendous amount of work on the
13codebase over the last three and a half months. We've had over 1600
14commits in that time period, doing ongoing cleanup and improvement.
15
16It can be hard to remember at times how much the codebase really has
17improved, but looking back at coreboot code from previous years, it's
18really impressive the changes that have happened. We'd like to thank
19everyone who has been involved in these changes. It's great to work
20with everyone involved, from the people who make the small cleanup
21patches and review all of the incoming changes to the people working
22on new chipsets and SoCs. We'd additionally like to thank all of those
23individuals who make the effort to become involved and report issues
24or push even a single patch to fix a bug that they've noticed.
25
26Many thanks to everyone involved!
27
28We plan to get the 4.21 release done in mid August, 2023.
29
30
31Significant or interesting changes
32----------------------------------
33
34
35### cpu/mp_init.c: Only enable CPUs once they execute code
36
37On some systems the BSP cannot know how many CPUs are present in the
38system. A typical use case is a multi socket system. Setting the enable
39flag only on CPUs that actually exist makes it more flexible.
40
41
42### cpu/x86/smm: Add PCI resource store functionality
43
44In certain cases data within protected memory areas like SMRAM could
45be leaked or modified if an attacker remaps PCI BARs to point within
46that area. Add support to the existing SMM runtime to allow storing
47PCI resources in SMRAM and then later retrieving them.
48
49This helps prevent moving BARs around to get SMM to access memory in
50areas that shouldn't be accessed.
51
52
53### acpi: Add SRAT x2APIC table support
54
55For platforms using X2APIC mode add SRAT x2APIC table
56generation. This allows the setup of proper SRAT tables.
57
58
59### drivers/usb/acpi: Add USB _DSM method to enable/disable USB LPM per port
60
61This patch supports projects to use _DSM to control USB3 U1/U2
62transition per port.
63
64More details can be found in
65https://web.archive.org/web/20230116084819/https://learn.microsoft.com/en-us/windows-hardware/drivers/bringup/usb-device-specific-method---dsm-
66
67The ACPI and USB driver of linux kernel need corresponding functions
68to support this feature. Please see
69https://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git/log/?h=port_check_acpi_dsm
70
71
72### drivers/efi: Add EFI variable store option support
73
74Add a driver to read and write EFI variables stored in a region device.
75This is particularly useful for EDK2 as payload and allows it to reuse
76existing EFI tools to set/get options used by the firmware.
77
78The write implementation is fault tolerant and doesn't corrupt the
79variable store. A faulting write might result in using the old value
80even though a 'newer' had been completely written.
81
82Implemented basic unit tests for header corruption, writing existing
83data and append new data into the store.
84
85Initial firmware region state:
86Initially the variable store region isn't formatted. Usually this is
87done in the EDK2 payload when no valid firmware volume could be found.
88It might be useful to do this offline or in coreboot to have a working
89option store on the first boot or when it was corrupted.
90
91Performance improvements:
92Right now the code always checks if the firmware volume header is valid.
93This could be optimised by caching the test result in heap. For write
94operations it would be good to cache the end of the variable store in
95the heap as well, instead of walking the whole store. For read
96operations caching the entire store could be considered.
97
98Reclaiming memory:
99The EFI variable store is append write only. To update an existing
100variable, first a new is written to the end of the store and then the
101previous is marked invalid. This only works on PNOR flash that allow to
102clear set bits, but keep cleared bits state.
103This mechanisms allows a fault tolerant write, but it also requires to
104"clean" the variable store from time to time. This cleaning would remove
105variables that have been marked "deleted".
106Such cleaning mechanism in turn must be fault tolerant and thus must use
107a second partition in the SPI flash as backup/working region.
108For now, cleaning is done in coreboot.
109
110Fault checking:
111The driver should check if a previous write was successful and if not
112mark variables as deleted on the next operation.
113
114
115### drivers/ocp/ewl: Add EWL driver for EWL type 3 error handling
116
117Add EWL (Enhanced Warning Log) driver which handles Intel EWL HOB
118and prints EWL type 3 primarily associated with MRC training failures.
119
120
121### Toolchain updates
122
123* Upgrade MPC from version 1.2.1 to 1.3.1
124* Upgrade MPFR from version 4.1.1 to 4.2.0
125* Upgrade CMake from version 3.25.0 to 3.26.3
126* Upgrade LLVM from version 15.0.6 to 15.0.7
127* Upgrade GCC from version 11.2.0 to 11.3.0
128* Upgrade binutils from version 2.37 to 2.40
129
130
131Additional coreboot changes
132---------------------------
133
134* Remove Yabits payload. Yabits is deprecated and archived.
135* Add DDR2 support to Intel GM45 code.
136* Fix superiotool compilation issues when using musl-libc.
137* Drop the Python 2 package from the coreboot-sdk.
138* Drop the Zephyr SDK from coreboot-sdk since the packaged version
139  was quite old and wasn’t really used.
140* Add inteltool support for the Intel "Emmitsburg" PCH.
141* Work to improve cache hit percentage when rebuilding using ccache.
142* Adding Sound-Open-Firmware drivers to chromebooks to enable audio on
143  non-chrome operating systems.
144* Improve and expand ACPI generation code.
145* Fix some issues for the RISC-V code.
146* Continue upstreaming the POWER9 architecture.
147* Add documentation for SBOM (Software Bill of Materials).
148* Add SimNow console logging support for AMD.
149* Do initial work on Xeon SPR
150* CMOS defaults greater than 128 bytes long now extend to bank 1.
151
152
153New Mainboards
154--------------
155
156* Asrock: B75M-ITX
157* Dell: Latitude E6400
158* Google: Aurash
159* Google: Boxy
160* Google: Constitution
161* Google: Gothrax
162* Google: Hades
163* Google: Myst
164* Google: Screebo
165* Google: Starmie
166* Google: Taranza
167* Google: Uldren
168* Google: Yavilla
169* HP: EliteBook 2170p
170* Intel: Archer City CRB
171* Intel: DQ67SW
172* Protectli: VP2420
173* Protectli: VP4630/VP4650
174* Protectli: VP4670
175* Siemens: MC EHL4
176* Siemens: MC EHL5
177* System76: lemp11
178* System76: oryp10
179* System76: oryp9
180
181
182Removed Mainboards
183------------------
184
185* Intel Icelake U DDR4/LPDDR4 RVP
186* Intel Icelake Y LPDDR4 RVP
187* Scaleway TAGADA
188
189
190Updated SoCs
191------------
192
193* Removed soc/intel/icelake
194
195
196Plans to move platform support to a branch
197------------------------------------------
198
199### Intel Quark SoC & Galileo mainboard
200
201The SoC Intel Quark is unmaintained and different efforts to revive it
202have so far failed.  The only user of this SoC ever was the Galileo
203board.
204
205Thus, to reduce the maintenance overhead for the community, support for
206the following components will be removed from the master branch and will
207be maintained on the release 4.20 branch.
208
209  * Intel Quark SoC
210  * Intel Galileo mainboard
211
212
213Statistics from the 4.19 to the 4.20 release
214--------------------------------------------
215
216Total Commits: 1630
217Average Commits per day: 13.72
218Total lines added: 102592
219Average lines added per commit: 62.94
220Number of patches adding more than 100 lines: 128
221Average lines added per small commit: 37.99
222Total lines removed: 34824
223Average lines removed per commit: 21.36
224Total difference between added and removed: 67768
225Total authors: ~170
226New authors: ~35
227
228
229Significant Known and Open Issues
230---------------------------------
231
232Issues from the coreboot bugtracker: https://ticket.coreboot.org/
233```{eval-rst}
234+-----+-----------------------------------------------------------------+
235| #   | Subject                                                         |
236+=====+=================================================================+
237| 478 | X200 booting Linux takes a long time with TSC                   |
238+-----+-----------------------------------------------------------------+
239| 474 | X200s crashes after graphic init with 8GB RAM                   |
240+-----+-----------------------------------------------------------------+
241| 457 | Haswell (t440p): CAR mem region conflicts with CBFS_SIZE > 8mb  |
242+-----+-----------------------------------------------------------------+
243| 453 | Intel HDMI / DP Audio device not showing up after libgfxinit    |
244+-----+-----------------------------------------------------------------+
245| 449 | ThinkPad T440p fail to start, continuous beeping & LED blinking |
246+-----+-----------------------------------------------------------------+
247| 448 | Thinkpad T440P ACPI Battery Value Issues                        |
248+-----+-----------------------------------------------------------------+
249| 446 | Optiplex 9010 No Post                                           |
250+-----+-----------------------------------------------------------------+
251| 439 | Lenovo X201 Turbo Boost not working (stuck on 2,4GHz)           |
252+-----+-----------------------------------------------------------------+
253| 427 | x200: Two battery charging issues                               |
254+-----+-----------------------------------------------------------------+
255| 414 | X9SAE-V: No USB keyboard init on SeaBIOS using Radeon RX 6800XT |
256+-----+-----------------------------------------------------------------+
257| 412 | x230 reboots on suspend                                         |
258+-----+-----------------------------------------------------------------+
259| 393 | T500 restarts rather than waking up from suspend                |
260+-----+-----------------------------------------------------------------+
261| 350 | I225 PCIe device not detected on Harcuvar                       |
262+-----+-----------------------------------------------------------------+
263| 327 | OperationRegion (OPRG, SystemMemory, ASLS, 0x2000) causes BSOD  |
264+-----+-----------------------------------------------------------------+
265```
266