mb/hp: Add HP EliteBook Folio 9480m

The code is based on autoport, with necessary modifications.

This laptop uses SMSC MEC1322 embedded controller, but the EC
interface is the same as the EliteBook laptops of previous generations
that use KBC1126 EC. So it still uses ec/hp/kbc1126, but does not need
EC firmware inserted into CBFS. We also need to leave the end of the
OEM flash content untouched, so the default ROM size is set to 12MiB
instead of 16MiB, and we need to modify the IFD when flashing.

Thanks to persmule for providing the laptop and pointing out how to
program the system flash chip of it.

Change-Id: I2328c43cbb1f488aa1d0ddd9116814d971e5d8ae
Signed-off-by: Iru Cai <mytbk920423@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45578
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

3 files changed, 157 insertions, 0 deletions

diff --git a/Documentation/mainboard/hp/folio_9480m.md b/Documentation/mainboard/hp/folio_9480m.md
new file mode 100644
index 0000000000..20eed08a66
--- /dev/null
+++ b/Documentation/mainboard/hp/folio_9480m.md
@@ -0,0 +1,156 @@
+# HP EliteBook Folio 9480m
+
+This page is about the notebook [HP EliteBook Folio 9480m].
+
+## Release status
+
+HP EliteBook Folio 9480m was released in 2014 and is now end of life.
+It can be bought from a secondhand market like Taobao or eBay.
+
+## Required proprietary blobs
+
+The following blobs are required to operate the hardware:
+
+1. EC firmware
+2. Intel ME firmware
+3. mrc.bin
+
+HP EliteBook Folio 9480m uses SMSC MEC1322 as its embedded controller.
+The EC firmware is stored in the flash chip, but we don't need to touch it
+or use it in the coreboot build process.
+
+Intel ME firmware is in the flash chip. It is not needed when building coreboot.
+
+The Haswell memory reference code binary is needed when building coreboot.
+Please see [mrc.bin](../../northbridge/intel/haswell/mrc.bin).
+
+## Programming
+
+Before flashing, remove the battery and the hard drive cover according to the
+[Maintenance and Service Guide] of this laptop.
+
+![Two flash chips of HP EliteBook Folio 9480m](folio_9480m_flash.webp)
+
+HP EliteBook Folio 9480m has two flash chips, a 16MiB system flash, and a 2MiB
+private flash. To install coreboot, we need to program both flash chips.
+Read [HP Sure Start] for detailed information.
+
+To access the system flash, we need to connect the AC adapter to the machine,
+then clip on the flash chip with an SOIC-8 clip. An [STM32-based flash programmer]
+made with an STM32 development board is tested to work.
+
+To access the private flash chip, we can use a ch341a based flash programmer and
+flash the chip with the AC adapter disconnected.
+
+Before flashing coreboot, we need to do the following:
+
+1. Erase the private flash to disable the IFD protection
+2. Modify the IFD to shrink the BIOS region, so that we'll not use or override
+   the protected bootblock and PEI region, as well as the EC firmware
+
+To erase the private flash chip, attach it with the flash programmer via the SOIC-8 clip,
+then run:
+
+    flashrom -p <programmer> --erase
+
+To modify the IFD, we need a new flash layout. The flash layout of the OEM firmware is:
+
+    00000000:00000fff fd
+    00001000:00002fff gbe
+    00003000:005fffff me
+    00600000:00ffffff bios
+
+The default coreboot configuration sets the flash chip size to 12MiB, so set the end of the
+BIOS region to 0xbfffff in the new layout. The modified IFD is as follows (Platform Data
+region pd is the region protected by HP Sure Start):
+
+    00000000:00000fff fd
+    00001000:00002fff gbe
+    00003000:005fffff me
+    00600000:00bfffff bios
+    00eb5000:00ffffff pd
+
+Write the above layout in a file, and use ifdtool to modify the IFD of a flash image.
+Suppose the above layout file is ``layout.txt`` and the origin content of the system flash
+is in ``factory-sys.rom``, run:
+
+    ifdtool -n layout.txt factory-sys.rom
+
+Then a flash image with a new IFD will be in ``factory-sys.rom.new``.
+
+Flash the IFD of the system flash:
+
+    flashrom -p <programmer> --ifd -i fd -w factory-sys.rom.new
+
+Then flash the coreboot image:
+
+    # first extend the 12M coreboot.rom to 16M
+    fallocate -l 16M build/coreboot.rom
+    flashrom -p <programmer> --ifd -i bios -w build/coreboot.rom
+
+After coreboot is installed, the coreboot firmware can be updated with internal flashing:
+
+    flashrom -p internal --ifd -i bios --noverify-all -w build/coreboot.rom
+
+## Debugging
+
+The board can be debugged with EHCI debug. The EHCI debug port is the USB port on the left.
+
+## Test status
+
+### Known issues
+
+- GRUB payload freezes just like previous EliteBook laptops
+- Sometimes the PCIe WLAN module can not be found in the OS after booting to the system
+- Sometimes all the USB devices can not be found in the OS after S3 resume
+
+### Untested
+
+- Fingerprint reader
+- Smart Card reader
+
+### Working
+
+- i5-4310U CPU with 4G+4G memory
+- SATA and M.2 SATA disk
+- Ethernet
+- WLAN
+- WWAN
+- SD card reader
+- USB
+- Keyboard and touchpad
+- DisplayPort
+- VGA
+- Dock
+- Audio output from speaker and headphone jack
+- Webcam
+- TPM
+- EC ACPI
+- S3 resume
+- Arch Linux with Linux 5.8.9
+- Memory initialization with mrc.bin version 1.6.1 Build 2
+- Graphics initialization with libgfxinit
+- Payload: SeaBIOS, Tianocore
+- EC firmware
+  - KBC Revision 92.15 from OEM firmware version 01.33
+  - KBC Revision 92.17 from OEM firmware version 01.50
+- Internal flashing under coreboot
+
+## Technology
+
+```eval_rst
++------------------+-----------------------------+
+| CPU              | Intel Haswell-ULT           |
++------------------+-----------------------------+
+| PCH              | Intel Lynx Point Low Power  |
++------------------+-----------------------------+
+| EC               | SMSC MEC1322                |
++------------------+-----------------------------+
+| Coprocessor      | Intel Management Engine     |
++------------------+-----------------------------+
+```
+
+[HP EliteBook Folio 9480m]: https://support.hp.com/us-en/product/hp-elitebook-folio-9480m-notebook-pc/7089926
+[Maintenance and Service Guide]: http://h10032.www1.hp.com/ctg/Manual/c05228980
+[STM32-based flash programmer]: https://github.com/dword1511/stm32-vserprog
+[HP Sure Start]: hp_sure_start.md
diff --git a/Documentation/mainboard/hp/folio_9480m_flash.webp b/Documentation/mainboard/hp/folio_9480m_flash.webp
new file mode 100644
index 0000000000..1abc306517
--- /dev/null
+++ b/Documentation/mainboard/hp/folio_9480m_flash.webp
diff --git a/Documentation/mainboard/index.md b/Documentation/mainboard/index.md
index 60fb89949a..4a1f74bc42 100644
--- a/Documentation/mainboard/index.md
+++ b/Documentation/mainboard/index.md
@@ -64,6 +64,7 @@ The boards in this section are not real mainboards, but emulators.
 - [HP Sure Start](hp/hp_sure_start.md)
 - [EliteBook 2560p](hp/2560p.md)
 - [EliteBook 8760w](hp/8760w.md)
+- [EliteBook Folio 9480m](hp/folio_9480m.md)
 
 ## Intel