util/apcb: Add apcb_edit tool

On the Picasso architecture, the PSP is responsible for setting up DRAM
before releasing the x86. The APCB (AGESA PSP Configuration Block)
contains multiple SPDs and the GPIO numbers used to select the correct
SPD. Since the source to build the APCBs is not public, it can't be
built as part of the coreboot build. To work around this problem, we use
a template APCB and inject the relevant information.

BUG=b:147042464

Signed-off-by: Rob Barnes <robbarnes@google.com>
Change-Id: I88a09743f8e8a184c47071ee5e417f5b6bdb7467
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/coreboot/+/2123799
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41380
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-by: Furquan Shaikh <furquan@google.com>
This commit is contained in:
Rob Barnes 2020-03-27 01:13:21 -06:00 committed by Patrick Georgi
parent 5dd76fd4cc
commit f836a234e2
2 changed files with 188 additions and 0 deletions

3
util/apcb/README Normal file
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The necessary tools for building APCBs are not available for use by coreboot.
This tool allows patching an existing APCB binary with specific SPDs
and GPIO selection pins.

185
util/apcb/apcb_edit.py Executable file
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#! /usr/bin/env python
# Script for editing APCB binaries, such as injecting SPDs and GPIO
# configurations.
import sys
import re
import argparse
from collections import namedtuple
from struct import *
GPIO_MAGIC = bytes.fromhex('fadeddad' * 3)
SPD_MAGIC = bytes.fromhex('f005ba110000')
EMPTY_SPD = b'\x00' * 512
spd_ssp_struct_fmt = '??B?IIBBBxIIBBBx'
spd_ssp_struct = namedtuple(
'spd_ssp_struct', 'SpdValid, DimmPresent, \
PageAddress, NvDimmPresent, \
DramManufacturersIDCode, Address, \
SpdMuxPresent, MuxI2CAddress, MuxChannel, \
Technology, Package, SocketNumber, \
ChannelNumber, DimmNumber')
def parseargs():
parser = argparse.ArgumentParser(description='Inject SPDs and SPD GPIO \
selection pins into APCB binaries')
parser.add_argument(
'apcb_in',
nargs='?',
type=argparse.FileType('rb'),
default=sys.stdin,
help='APCB input file')
parser.add_argument(
'apcb_out',
nargs='?',
type=argparse.FileType('wb'),
default=sys.stdout,
help='APCB output file')
parser.add_argument(
'--spd_0_0',
type=argparse.FileType('r'),
help='SPD input file for channel 0, dimm 0')
parser.add_argument(
'--spd_0_1',
type=argparse.FileType('r'),
help='SPD input file for channel 0, dimm 1')
parser.add_argument(
'--spd_1_0',
type=argparse.FileType('r'),
help='SPD input file for channel 1, dimm 0')
parser.add_argument(
'--spd_1_1',
type=argparse.FileType('r'),
help='SPD input file for channel 1, dimm 1')
parser.add_argument(
'--hex',
action='store_true',
help='SPD input file is hex encoded, binary otherwise')
parser.add_argument(
'--board_id_gpio0',
type=int,
required=True,
nargs=3,
help='Board ID GPIO 0: NUMBER IO_MUX BANK_CTRL')
parser.add_argument(
'--board_id_gpio1',
type=int,
required=True,
nargs=3,
help='Board ID GPIO 1: NUMBER IO_MUX BANK_CTRL')
parser.add_argument(
'--board_id_gpio2',
type=int,
required=True,
nargs=3,
help='Board ID GPIO 2: NUMBER IO_MUX BANK_CTRL')
parser.add_argument(
'--board_id_gpio3',
type=int,
required=True,
nargs=3,
help='Board ID GPIO 3: NUMBER IO_MUX BANK_CTRL')
return parser.parse_args()
def chksum(data):
sum = 0
for b in data[:16] + data[17:]:
sum = (sum + b) & 0xff
return (0x100 - sum) & 0xff
def inject(orig, insert, offset):
return b''.join([orig[:offset], insert, orig[offset + len(insert):]])
def main():
args = parseargs()
print("Reading input APCB from %s\n" % (args.apcb_in.name))
apcb = args.apcb_in.read()
orig_apcb_len = len(apcb)
gpio_offset = apcb.find(GPIO_MAGIC)
assert gpio_offset > 0, "GPIO magic number not found"
print('GPIO magic number found at offset 0x%x\n' % gpio_offset)
gpio_array = (args.board_id_gpio0 + args.board_id_gpio1 +
args.board_id_gpio2 + args.board_id_gpio3)
print('Writing SPD GPIO array %s\n' % gpio_array)
apcb = inject(apcb, pack('BBBBBBBBBBBB', *gpio_array), gpio_offset)
spd_offset = 0
while True:
spd_offset = apcb.find(SPD_MAGIC, spd_offset)
if spd_offset < 0:
break
spd_ssp_offset = spd_offset - calcsize(spd_ssp_struct_fmt)
spd_ssp_bytes = apcb[spd_ssp_offset:spd_offset]
spd_ssp = spd_ssp_struct._make(
unpack(spd_ssp_struct_fmt, spd_ssp_bytes))
assert spd_ssp.DimmNumber >= 0 and spd_ssp.DimmNumber <= 1, \
"Unexpected dimm number found in APCB"
assert spd_ssp.ChannelNumber >= 0 and spd_ssp.ChannelNumber <= 1, \
"Unexpected channel number found in APCB"
print("Found SPD magic number with channel %d and dimm %d "
"at offset 0x%x\n" % (spd_ssp.ChannelNumber, spd_ssp.DimmNumber,
spd_offset))
dimm_channel = (spd_ssp.ChannelNumber, spd_ssp.DimmNumber)
spd = None
if dimm_channel == (0, 0) and args.spd_0_0:
spd = args.spd_0_0.read()
elif dimm_channel == (0, 1) and args.spd_0_1:
spd = args.spd_0_1.read()
elif dimm_channel == (1, 0) and args.spd_1_0:
spd = args.spd_1_0.read()
elif dimm_channel == (1, 1) and args.spd_1_1:
spd = args.spd_1_0.read()
if spd:
if args.hex:
spd = re.sub(r'#.*', '', spd)
spd = re.sub(r'\s+', '', spd)
spd = bytes.fromhex(spd)
else:
spd = spd.encode()
assert len(spd) == 512, \
"Expected SPD to be 512 bytes, got %d" % len(spd)
print("Enabling channel %d, dimm %d and injecting SPD\n" %
(spd_ssp.ChannelNumber, spd_ssp.DimmNumber))
spd_ssp = spd_ssp._replace(SpdValid=True, DimmPresent=True)
else:
print("Disabling channel %d, dimm %d and clearing SPD\n" %
(spd_ssp.ChannelNumber, spd_ssp.DimmNumber))
spd_ssp = spd_ssp._replace(SpdValid=False, DimmPresent=False)
spd = EMPTY_SPD
apcb = inject(apcb, pack(spd_ssp_struct_fmt, *spd_ssp), spd_ssp_offset)
apcb = inject(apcb, spd, spd_offset)
spd_offset += 512
print("Fixing checksum and writing to %s\n" % (args.apcb_out.name))
apcb = inject(apcb, bytes([chksum(apcb)]), 16)
assert chksum(apcb) == apcb[16], "Checksum is invalid"
assert orig_apcb_len == len(apcb), \
"The size of the APCB binary changed, this should not happen."
args.apcb_out.write(apcb)
if __name__ == "__main__":
main()