I had exactly the same issue with an ASUS UX305CA ultrabook. Downgrading to the previous version of intel-microcode resolved it for me as well. I was able to get intel-microcode 3.20160607.1 working by upgrading from UX305CA.205 to UX305CA.300 BIOS revision from ASUS.
----------- # dmidecode 3.0 Getting SMBIOS data from sysfs. SMBIOS 3.0.0 present. Table at 0x87656000. Handle 0x0000, DMI type 0, 24 bytes BIOS Information Vendor: American Megatrends Inc. Version: UX305CA.300 Release Date: 06/08/2016 Address: 0xF0000 Runtime Size: 64 kB ROM Size: 6016 kB Characteristics: PCI is supported BIOS is upgradeable BIOS shadowing is allowed Boot from CD is supported Selectable boot is supported BIOS ROM is socketed EDD is supported 5.25"/1.2 MB floppy services are supported (int 13h) 3.5"/720 kB floppy services are supported (int 13h) 3.5"/2.88 MB floppy services are supported (int 13h) Print screen service is supported (int 5h) 8042 keyboard services are supported (int 9h) Serial services are supported (int 14h) Printer services are supported (int 17h) ACPI is supported USB legacy is supported Smart battery is supported BIOS boot specification is supported Targeted content distribution is supported UEFI is supported BIOS Revision: 5.11 Handle 0x0001, DMI type 1, 27 bytes System Information Manufacturer: ASUSTeK COMPUTER INC. Product Name: UX305CA Version: 1.0 Serial Number: FBN0CJ079030468 UUID: 6AE3C30A-AE8A-804D-9527-6CE0851C1EF6 Wake-up Type: Power Switch SKU Number: ASUS-NotebookSKU Family: UX Handle 0x0002, DMI type 2, 15 bytes Base Board Information Manufacturer: ASUSTeK COMPUTER INC. Product Name: UX305CA Version: 1.0 Serial Number: BSN12345678901234567 Asset Tag: ATN12345678901234567 Features: Board is a hosting board Board is replaceable Location In Chassis: MIDDLE Chassis Handle: 0x0003 Type: Motherboard Contained Object Handles: 0 Handle 0x0003, DMI type 3, 22 bytes Chassis Information Manufacturer: ASUSTeK COMPUTER INC. Type: Notebook Lock: Not Present Version: 1.0 Serial Number: FBN0CJ079030468 Asset Tag: ATN12345678901234567 Boot-up State: Safe Power Supply State: Safe Thermal State: Safe Security Status: None OEM Information: 0x00000000 Height: Unspecified Number Of Power Cords: 1 Contained Elements: 0 SKU Number: Default string Handle 0x0004, DMI type 10, 26 bytes On Board Device 1 Information Type: Video Status: Enabled Description: VGA On Board Device 2 Information Type: Ethernet Status: Enabled Description: GLAN On Board Device 3 Information Type: Ethernet Status: Enabled Description: WLAN On Board Device 4 Information Type: Sound Status: Enabled Description: Audio CODEC On Board Device 5 Information Type: SATA Controller Status: Enabled Description: SATA Controller On Board Device 6 Information Type: Other Status: Enabled Description: USB 2.0 Controller On Board Device 7 Information Type: Other Status: Enabled Description: USB 3.0 Controller On Board Device 8 Information Type: Other Status: Enabled Description: SMBus Controller On Board Device 9 Information Type: Other Status: Enabled Description: Card Reader On Board Device 10 Information Type: Other Status: Enabled Description: Cmos Camera On Board Device 11 Information Type: Other Status: Enabled Description: Bluetooth Handle 0x0005, DMI type 11, 5 bytes OEM Strings String 1: String 2: String 3: String 4: 90NB0AA3-M00800 String 5: String 6: String 7: String 8: String 9: String 10: Handle 0x000C, DMI type 32, 20 bytes System Boot Information Status: No errors detected Handle 0x000D, DMI type 7, 19 bytes Cache Information Socket Designation: L1 Cache Configuration: Enabled, Not Socketed, Level 1 Operational Mode: Write Back Location: Internal Installed Size: 64 kB Maximum Size: 64 kB Supported SRAM Types: Synchronous Installed SRAM Type: Synchronous Speed: Unknown Error Correction Type: Parity System Type: Data Associativity: 8-way Set-associative Handle 0x000E, DMI type 7, 19 bytes Cache Information Socket Designation: L1 Cache Configuration: Enabled, Not Socketed, Level 1 Operational Mode: Write Back Location: Internal Installed Size: 64 kB Maximum Size: 64 kB Supported SRAM Types: Synchronous Installed SRAM Type: Synchronous Speed: Unknown Error Correction Type: Parity System Type: Instruction Associativity: 8-way Set-associative Handle 0x000F, DMI type 7, 19 bytes Cache Information Socket Designation: L2 Cache Configuration: Enabled, Not Socketed, Level 2 Operational Mode: Write Back Location: Internal Installed Size: 512 kB Maximum Size: 512 kB Supported SRAM Types: Synchronous Installed SRAM Type: Synchronous Speed: Unknown Error Correction Type: Single-bit ECC System Type: Unified Associativity: 4-way Set-associative Handle 0x0010, DMI type 7, 19 bytes Cache Information Socket Designation: L3 Cache Configuration: Enabled, Not Socketed, Level 3 Operational Mode: Write Back Location: Internal Installed Size: 4096 kB Maximum Size: 4096 kB Supported SRAM Types: Synchronous Installed SRAM Type: Synchronous Speed: Unknown Error Correction Type: Multi-bit ECC System Type: Unified Associativity: 16-way Set-associative Handle 0x0011, DMI type 4, 48 bytes Processor Information Socket Designation: U3E1 Type: Central Processor Family: <OUT OF SPEC> Manufacturer: Intel(R) Corporation ID: E3 06 04 00 FF FB EB BF Version: Intel(R) Core(TM) m3-6Y30 CPU @ 0.90GHz Voltage: 0.6 V External Clock: 100 MHz Max Speed: 8300 MHz Current Speed: 1100 MHz Status: Populated, Enabled Upgrade: Other L1 Cache Handle: 0x000E L2 Cache Handle: 0x000F L3 Cache Handle: 0x0010 Serial Number: To Be Filled By O.E.M. Asset Tag: To Be Filled By O.E.M. Part Number: To Be Filled By O.E.M. Core Count: 2 Core Enabled: 2 Thread Count: 4 Characteristics: 64-bit capable Multi-Core Hardware Thread Execute Protection Enhanced Virtualization Power/Performance Control Handle 0x0012, DMI type 16, 23 bytes Physical Memory Array Location: System Board Or Motherboard Use: System Memory Error Correction Type: None Maximum Capacity: 16 GB Error Information Handle: Not Provided Number Of Devices: 2 Handle 0x0013, DMI type 17, 40 bytes Memory Device Array Handle: 0x0012 Error Information Handle: Not Provided Total Width: 64 bits Data Width: 64 bits Size: 4096 MB Form Factor: SODIMM Set: None Locator: ChannelA-DIMM0 Bank Locator: BANK 0 Type: LPDDR3 Type Detail: Synchronous Speed: 1867 MHz Manufacturer: Elpida Serial Number: 00000000 Asset Tag: 9876543210 Part Number: Rank: 2 Configured Clock Speed: 1867 MHz Minimum Voltage: Unknown Maximum Voltage: Unknown Configured Voltage: 1.2 V Handle 0x0014, DMI type 17, 40 bytes Memory Device Array Handle: 0x0012 Error Information Handle: Not Provided Total Width: 64 bits Data Width: 64 bits Size: 4096 MB Form Factor: SODIMM Set: None Locator: ChannelB-DIMM0 Bank Locator: BANK 2 Type: LPDDR3 Type Detail: Synchronous Speed: 1867 MHz Manufacturer: Elpida Serial Number: 00000000 Asset Tag: 9876543210 Part Number: Rank: 2 Configured Clock Speed: 1867 MHz Minimum Voltage: Unknown Maximum Voltage: Unknown Configured Voltage: 1.2 V Handle 0x0015, DMI type 19, 31 bytes Memory Array Mapped Address Starting Address: 0x00000000000 Ending Address: 0x001FFFFFFFF Range Size: 8 GB Physical Array Handle: 0x0012 Partition Width: 2 Handle 0x0016, DMI type 221, 12 bytes OEM-specific Type Header and Data: DD 0C 16 00 01 01 00 01 07 00 00 00 Strings: Reference Code - ACPI Handle 0x0017, DMI type 20, 35 bytes Memory Device Mapped Address Starting Address: 0x00000000000 Ending Address: 0x000FFFFFFFF Range Size: 4 GB Physical Device Handle: 0x0013 Memory Array Mapped Address Handle: 0x0015 Partition Row Position: Unknown Interleave Position: 1 Interleaved Data Depth: 1 Handle 0x0018, DMI type 20, 35 bytes Memory Device Mapped Address Starting Address: 0x00100000000 Ending Address: 0x001FFFFFFFF Range Size: 4 GB Physical Device Handle: 0x0014 Memory Array Mapped Address Handle: 0x0015 Partition Row Position: Unknown Interleave Position: 2 Interleaved Data Depth: 1 Handle 0x0019, DMI type 130, 20 bytes OEM-specific Type Header and Data: 82 14 19 00 24 41 4D 54 00 00 00 00 00 A5 AF 02 C0 00 00 00 Handle 0x001A, DMI type 131, 64 bytes OEM-specific Type Header and Data: 83 40 1A 00 31 00 00 00 00 00 00 00 00 00 00 00 F8 00 46 9D 00 00 00 00 01 00 00 00 00 00 0B 00 95 04 00 00 00 00 00 00 FE 00 FF FF 00 00 00 00 00 00 00 00 22 00 00 00 76 50 72 6F 00 00 00 00 Handle 0x001B, DMI type 221, 26 bytes OEM-specific Type Header and Data: DD 1A 1B 00 03 01 00 01 07 00 00 00 02 00 00 00 00 8A 00 03 00 00 05 00 00 00 Strings: Reference Code - CPU uCode Version TXT ACM version Handle 0x001C, DMI type 221, 26 bytes OEM-specific Type Header and Data: DD 1A 1C 00 03 01 00 01 07 00 00 00 02 00 01 07 00 00 00 03 04 0B 00 00 95 04 Strings: Reference Code - ME 11.0 MEBx version ME Firmware Version Consumer SKU Handle 0x001D, DMI type 221, 68 bytes OEM-specific Type Header and Data: DD 44 1D 00 09 01 00 01 07 00 00 00 02 03 FF FF FF FF FF 04 00 FF FF FF 21 00 05 00 FF FF FF 21 00 06 00 FF FF FF FF FF 07 00 3E 00 00 00 00 08 00 34 00 00 00 00 09 00 3E 00 00 00 00 0A 00 34 00 00 00 00 Strings: Reference Code - SKL PCH PCH-CRID Status Disabled PCH-CRID Original Value PCH-CRID New Value OPROM - RST - RAID SKL PCH H Bx Hsio Version SKL PCH H Dx Hsio Version SKL PCH LP Bx Hsio Version SKL PCH LP Cx Hsio Version Handle 0x001E, DMI type 221, 54 bytes OEM-specific Type Header and Data: DD 36 1E 00 07 01 00 01 07 00 00 00 02 00 01 07 00 00 00 03 00 01 07 00 00 00 04 05 FF FF FF FF FF 06 00 FF FF FF 08 00 07 00 FF FF FF 08 00 08 00 FF FF FF FF FF Strings: Reference Code - SA - System Agent Reference Code - MRC SA - PCIe Version SA-CRID Status Disabled SA-CRID Original Value SA-CRID New Value OPROM - VBIOS Handle 0x001F, DMI type 221, 96 bytes OEM-specific Type Header and Data: DD 60 1F 00 0D 01 00 00 00 00 00 00 02 00 FF FF FF FF FF 03 04 FF FF FF FF FF 05 06 FF FF FF FF FF 07 08 FF FF FF FF FF 09 00 00 00 00 00 00 0A 00 FF FF FF FF FF 0B 00 FF FF 00 00 00 0C 00 00 09 00 42 10 0D 00 02 00 00 00 00 0E 00 FF FF FF FF FF 0F 00 FF FF FF FF FF 10 11 01 02 02 03 00 Strings: Lan Phy Version Sensor Firmware Version Debug Mode Status Enabled Performance Mode Status Disabled Debug Use USB(Disabled:Serial) Disabled ICC Overclocking Version UNDI Version EC FW Version GOP Version BIOS Guard Version Base EC FW Version EC-EC Protocol Version Royal Park Version BP1.2.2.0_RP03 Handle 0x0020, DMI type 136, 6 bytes OEM-specific Type Header and Data: 88 06 20 00 00 00 Handle 0x0021, DMI type 14, 23 bytes Group Associations Name: Firmware Version Info Items: 6 0x0016 (<OUT OF SPEC>) 0x001B (<OUT OF SPEC>) 0x001C (<OUT OF SPEC>) 0x001D (<OUT OF SPEC>) 0x001E (<OUT OF SPEC>) 0x001F (<OUT OF SPEC>) Handle 0x0022, DMI type 14, 8 bytes Group Associations Name: $MEI Items: 1 0x0000 (<OUT OF SPEC>) Handle 0x0023, DMI type 219, 81 bytes OEM-specific Type Header and Data: DB 51 23 00 01 03 01 45 02 00 90 06 03 10 86 00 00 00 00 00 40 08 00 00 00 00 00 00 00 00 40 02 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 03 00 00 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Strings: MEI1 MEI2 MEI3 Handle 0x0024, DMI type 13, 22 bytes BIOS Language Information Language Description Format: Long Installable Languages: 1 en|US|iso8859-1 Currently Installed Language: en|US|iso8859-1 Handle 0x0025, DMI type 127, 4 bytes End Of Table On Tue, 28 Jun 2016 08:58:43 +0200 Jochen <debian-bts@jochen.sprickerho f.de> wrote: > Package: intel-microcode > Version: 3.20160607.1 > Severity: important > > Dear Maintainer, > > my system boots only in 1 out of 5 cases (or less) with the current version in > unstable. It stops after loading the initrd without further information. > Downgrading to 3.20151106.2 makes it work again. > > $ lscpu > > Architecture: x86_64 > CPU op-mode(s): 32-bit, 64-bit > Byte Order: Little Endian > CPU(s): 4 > On-line CPU(s) list: 0-3 > Thread(s) per core: 2 > Core(s) per socket: 2 > Socket(s): 1 > NUMA node(s): 1 > Vendor ID: GenuineIntel > CPU family: 6 > Model: 78 > Model name: Intel(R) Core(TM) i7-6500U CPU @ 2.50GHz > Stepping: 3 > CPU MHz: 499.890 > CPU max MHz: 3100,0000 > CPU min MHz: 400,0000 > BogoMIPS: 5183.89 > Virtualization: VT-x > L1d cache: 32K > L1i cache: 32K > L2 cache: 256K > L3 cache: 4096K > NUMA node0 CPU(s): 0-3 > Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc art arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch epb intel_pt tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx rdseed adx smap clflushopt xsaveopt xsavec xgetbv1 dtherm ida arat pln pts hwp hwp_notify hwp_act_window hwp_epp > > > -- System Information: > Debian Release: stretch/sid > APT prefers unstable > APT policy: (500, 'unstable'), (1, 'experimental') > Architecture: amd64 (x86_64) > Foreign Architectures: i386 > > Kernel: Linux 4.6.0-1-amd64 (SMP w/4 CPU cores) > Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8) > Shell: /bin/sh linked to /bin/dash > Init: systemd (via /run/systemd/system) > > Versions of packages intel-microcode depends on: > ii iucode-tool 1.6.1-1 > > Versions of packages intel-microcode recommends: > ii initramfs-tools 0.125 > > intel-microcode suggests no packages. > > -- no debconf information