HP EliteBook series

This document is about HP EliteBook series laptops up to Ivy Bridge era which use SMSC KBC1126 as embedded controller.

EC

SMSC KBC1098/KBC1126 has been used in HP EliteBooks for many generations. They use similar EC firmware that will load other code and data from the SPI flash chip, so we need to put some firmware blobs to the coreboot image.

The following document takes EliteBook 2760p as an example.

First, you need to extract the blobs needed by EC firmware using util/kbc1126. You can extract them from your backup firmware image, or firmware update provided by HP with unar as follows:

wget https://ftp.hp.com/pub/softpaq/sp79501-80000/sp79710.exe
unar sp79710.exe
${COREBOOT_DIR}/util/kbc1126/kbc1126_ec_dump sp79710/Rompaq/68SOU.BIN
mv 68SOU.BIN.fw1 ${COREBOOT_DIR}/2760p-fw1.bin
mv 68SOU.BIN.fw2 ${COREBOOT_DIR}/2760p-fw2.bin

When you config coreboot, select:

Chipset --->
  [*] Add firmware images for KBC1126 EC
      (2760p-fw1.bin) KBC1126 firmware #1 path and filename
      (2760p-fw2.bin) KBC1126 filename #2 path and filename

Super I/O

EliteBook 8000 series laptops have SMSC LPC47n217 Super I/O to provide a serial port and a parallel port, you can debug the laptop via this serial port.

porting

To port coreboot to an HP EliteBook laptop, you need to do the following:

select Kconfig option EC_HP_KBC1126
select Kconfig option SUPERIO_SMSC_LPC47N217 if there is LPC47n217 Super I/O
initialize EC and Super I/O in romstage
add EC and Super I/O support to devicetree.cb

To get the related values for EC in devicetree.cb, you need to extract the EFI module EcThermalInit from the vendor UEFI firmware with UEFITool. Usually, ec_data_port, ec_cmd_port and ec_ctrl_reg has the following values:

For xx60 series: 0x60, 0x64, 0xca
For xx70 series: 0x62, 0x66, 0x81

You can use radare2 and the following r2pipe Python script to find these values from the EcThermalInit EFI module:

#!/usr/bin/env python

# install radare2 and use `pip3 install --user r2pipe` to install r2pipe

import r2pipe
import sys

if len(sys.argv) < 2:
    fn = "ecthermalinit.efi"
else:
    fn = sys.argv[1]

r2 = r2pipe.open(fn)
r2.cmd("aa")
entryf = r2.cmdj("pdfj")

for insn in entryf["ops"]:
    if "lea r8" in insn["opcode"]:
        _callback = insn["ptr"]
        break

r2.cmd("af @ {}".format(_callback))
callbackf_insns = r2.cmdj("pdfj @ {}".format(_callback))["ops"]

def find_port(addr):
    ops = r2.cmdj("pdfj @ {}".format(addr))["ops"]
    for insn in ops:
        if "lea r8d" in insn["opcode"]:
            return insn["ptr"]

ctrl_reg_found = False

for i in range(0, len(callbackf_insns)):
    if not ctrl_reg_found and "mov cl" in callbackf_insns[i]["opcode"]:
        ctrl_reg_found = True
        ctrl_reg = callbackf_insns[i]["ptr"]
        print("ec_ctrl_reg = 0x%02x" % ctrl_reg)
        cmd_port = find_port(callbackf_insns[i+1]["jump"])
        data_port = find_port(callbackf_insns[i+3]["jump"])
        print("ec_cmd_port = 0x%02x\nec_data_port = 0x%02x" % (cmd_port, data_port))

    if "mov bl" in callbackf_insns[i]["opcode"]:
        ctrl_value = callbackf_insns[i]["ptr"]
        print("ec_fan_ctrl_value = 0x%02x" % ctrl_value)