Here is more information from the UART output during boot:
[ 0.000000] Linux version 3.10.49-g0b014e2-dirty (gcc version 4.9.x-google 20140827 (prerelease) (GCC) ) #1
[ 0.000000] CPU: AArch64 Processor [410fd030] revision 0
[ 0.000000] Machine: Qualcomm Technologies, Inc. APQ 8016 SBC
…
[ 19.625227] msm8x16-asoc-wcd sound.66: default codec configured
[ 19.632250] msm8x16-asoc-wcd sound.66: ASoC: CODEC (null) not registered
[ 19.638037] msm8x16-asoc-wcd sound.66: snd_soc_register_card failed (-517)
[ 19.645189] platform sound.66: Driver msm8x16-asoc-wcd requests probe deferral
[ 19.655300] msm8x16-asoc-wcd sound.66: default codec configured
[ 19.662823] wcd-spmi-core msm8x16_wcd_codec-ffffffc0329d4400: Error: regulator not found
[ 19.682220] msm-pcm-routing qcom,msm-pcm-routing.37: ASoC: no dapm match for VOICE2_STUB_DL → Voice2 Stub → INTERNAL_BT_SCO_RX_Voice Mixer
[ 19.693997] msm-pcm-routing qcom,msm-pcm-routing.37: ASoC: Failed to add route VOICE2_STUB_DL → Voice2 Stub → INTERNAL_BT_SCO_RX_Voice Mixer
[ 19.699301] init: Detected MSM SOC ID=247 SOC VER=65536 BOARD TYPE=SBC
[ 19.699735] init: failed to open ‘/sys/class/graphics/fb2/msm_fb_type’
[ 19.700732] init: property ‘persist.sys.ssr.enable_debug’ doesn’t exist while expanding ‘${persist.sys.ssr.enable_debug}’
[ 19.700748] init: cannot expand ‘${persist.sys.ssr.enable_debug}’ while writing to ‘/sys/module/subsystem_restart/parameters/enable_debug’
[ 19.700767] init: property ‘persist.sys.mba_boot_timeout’ doesn’t exist while expanding ‘${persist.sys.mba_boot_timeout}’
[ 19.700780] init: cannot expand ‘${persist.sys.mba_boot_timeout}’ while writing to ‘/sys/module/pil_msa/parameters/pbl_mba_boot_timeout_ms’
[ 19.700797] init: property ‘persist.sys.modem_auth_timeout’ doesn’t exist while expanding ‘${persist.sys.modem_auth_timeout}’
[ 19.700809] init: cannot expand ‘${persist.sys.modem_auth_timeout}’ while writing to ‘/sys/module/pil_msa/parameters/modem_auth_timeout_ms’
[ 19.700826] init: property ‘persist.sys.pil_proxy_timeout’ doesn’t exist while expanding ‘${persist.sys.pil_proxy_timeout}’
[ 19.700838] init: cannot expand ‘${persist.sys.pil_proxy_timeout}’ while writing to ‘/sys/module/peripheral_loader/parameters/proxy_timeout_ms’
[ 19.838739] msm-pcm-routing qcom,msm-pcm-routing.37: ASoC: mux SLIM_0_RX AANC MUX has no paths
[ 19.849963] wcd-spmi-core msm8x16_wcd_codec-ffffffc0329d4400: ASoC: mux RX3 MIX1 INP3 has no paths
[ 19.858144] wcd-spmi-core msm8x16_wcd_codec-ffffffc0329d4400: ASoC: mux RX2 MIX1 INP3 has no paths
[ 19.894442] binder: 242:242 transaction failed 29189, size 0-0
[ 19.898172] init: cannot find ‘/system/bin/rfs_access’, disabling ‘rfs_access’
[ 19.898218] init: cannot find ‘/system/bin/tftp_server’, disabling ‘tftp_server’
[ 19.899003] init: cannot find ‘/system/bin/qseecomd’, disabling ‘qseecomd’
[ 19.935817] servicemanager (244) used greatest stack depth: 11128 bytes left
[ 19.956803] init: cannot find ‘/system/bin/rmt_storage’, disabling ‘rmt_storage’
CANNOT LINK EXECUTABLE DEPENDENCIES: [ 19.974185] init: cannot find ‘/system/bin/qcom-system-daemon’, disabling ‘qcomsysd’
[ 19.982099] init: cannot find ‘/system/bin/irsc_util’, disabling ‘irsc_util’
[ 19.989504] init: cannot find ‘/system/bin/ptt_socket_app’, disabling ‘ptt_socket_app’
[ 19.996536] init: cannot find ‘/system/bin/cnss_diag’, disabling ‘cnss_diag’
[ 20.003528] init: cannot find ‘/system/bin/usb_uicc_client’, disabling ‘usb_uicc_daemon’
[ 20.004897] installd (267) used greatest stack depth: 11016 bytes left
[ 20.019943] init: cannot find ‘/system/bin/qrngd’, disabling ‘qrngd’
[ 20.027075] init: cannot find ‘/system/bin/thermal-engine’, disabling ‘thermal-engine’
[ 20.036429] init: cannot find ‘/system/bin/imsqmidaemon’, disabling ‘imsqmidaemon’
[ 20.043239] init: cannot find ‘/system/bin/dts_configurator’, disabling ‘dts_configurator’
[ 20.054770] init: cannot find ‘/system/bin/cnd’, disabling ‘cnd’
[ 20.059796] init: cannot find ‘/system/bin/dpmd’, disabling ‘dpmd’
[ 20.066295] init: cannot find ‘/system/bin/cnss-daemon’, disabling ‘cnss-daemon’
[ 20.073436] init: cannot find ‘/system/bin/loc_launcher’, disabling ‘loc_launcher’
[ 20.081564] init: cannot find ‘/system/bin/ATFWD-daemon’, disabling ‘atfwd’
[ 20.089330] init: cannot find ‘/system/vendor/bin/RIDLClient.exe’, disabling ‘RIDL’
[ 20.096535] init: cannot find ‘/system/bin/mm-qcamera-daemon’, disabling ‘qcamerasvr’
[ 20.103869] init: cannot find ‘/system/bin/time_daemon’, disabling ‘time_daemon’
[ 20.111219] init: cannot find ‘/system/bin/audiod’, disabling ‘audiod’
[ 20.118297] init: cannot find ‘/system/bin/mm-pp-daemon’, disabling ‘ppd’
[ 20.125319] enable_store: android_usb: already disabled
[ 24.862409] apr_tal:open timeout
[ 24.864605] APR: Unable to open handle
[ 24.868337] afe_q6_interface_prepare: Unable to register AFE
[ 24.874003] afe_set_digital_codec_core_clock: Q6 interface prepare failed -19
[ 24.881097] failed to enable the MCLK
CANNOT LINK EXECUTABLE DEPENDENCIES: [ 25.043651] init: cannot find ‘/system/bin/mm-pp-daemon’, disabling ‘ppd’
[ 29.882407] apr_tal:open timeout
[ 29.884603] APR: Unable to open handle
[ 29.888337] afe_q6_interface_prepare: Unable to register AFE
[ 29.894014] afe_set_digital_codec_core_clock: Q6 interface prepare failed -19
[ 29.901094] failed to enable the MCLK
CANNOT LINK EXECUTABLE DEPENDENCIES: [ 30.044779] init: cannot find ‘/system/bin/mm-pp-daemon’, disabling ‘ppd’
[ 34.902441] apr_tal:open timeout
[ 34.904638] APR: Unable to open handle
[ 34.908372] afe_q6_interface_prepare: Unable to register AFE
[ 34.914050] afe_set_digital_codec_core_clock: Q6 interface prepare failed -19
[ 34.921130] failed to enable the MCLK
CANNOT LINK EXECUTABLE DEPENDENCIES: [ 35.044256] init: cannot find ‘/system/bin/mm-pp-daemon’, disabling ‘ppd’
[ 39.922419] apr_tal:open timeout
[ 39.924617] APR: Unable to open handle
[ 39.928349] afe_q6_interface_prepare: Unable to register AFE
[ 39.934041] afe_set_digital_codec_core_clock: Q6 interface prepare failed -19
[ 39.941108] failed to enable the MCLK
CANNOT LINK EXECUTABLE DEPENDENCIES: [ 40.043705] init: critical process ‘servicemanager’ exited 4 times in 4 minutes; rebooting into recovery mode
[ 40.053041] SysRq : Emergency Remount R/O
[ 44.942436] apr_tal:open timeout
[ 44.944630] APR: Unable to open handle
[ 44.948364] afe_q6_interface_prepare: Unable to register AFE
[ 44.954050] afe_set_digital_codec_core_clock: Q6 interface prepare failed -19
[ 44.961121] failed to enable the MCLK