| POST code |
Description of POST operation |
| 00 - 0F |
Debug Codes: can be used by any PEIM/driver for debug |
| 10 - 1F |
Host Processor |
| 10 |
Power-on initialization of the host processor (Boot Strap Processor) |
| 11 |
Host processor Cache initialization (including APs) |
| 12 |
Starting Application processor initialization |
| 13 |
SMM initialization |
| 14 |
LAN initialization |
| 15 |
Exit early platform init driver |
| 16 |
SMBUS driver initialization |
| 17 |
Entry to SMBUS execute read/write |
| 19 |
Entry to CK505 programming |
| 1F |
Unrecoverable CPU error |
| 20 - 2F |
Memory / Chipset |
| 21 |
Initializing a chipset component |
| 22 |
Reading SPD from memory DIMMs |
| 23 |
Detecting presence of memory DIMMs |
| 24 |
Programming timing parameters in the memory controller and the DIMMs |
| 25 |
Configuring memory |
| 26 |
Optimizing memory settings |
| 27 |
Initializing memory, such as ECC init |
| 28 |
Testing memory |
| 2F |
No memory detected or no useful memory detected |
| 30 - 3F |
Recovery |
| 30 |
Crisis Recovery has initiated per User request |
| 31 |
Crisis Recovery has initiated by software (corrupt flash) |
| 34 |
Loading recovery capsule |
| 35 |
Handing off control to the recovery capsule |
| 3F |
Unable to recover |
| 50 - 5F |
I/O Busses (PCI, USB, ISA, ATA, etc.) |
| 50 |
Enumerating PCI busses |
| 51 |
Allocating resources to PCI bus |
| 52 |
Hot Plug PCI controller initialization |
| 53 – 57 |
Reserved for PCI Bus |
| 58 |
Resetting USB bus |
| 59 |
Reserved for USB |
| 5A |
Resetting PATA/SATA bus and all devices |
| 5B |
Reserved for ATA |
| 5C |
Resetting SMBUS |
| 5D |
Reserved for SMBUS |
| 5F |
Unrecoverable I/O bus error |
| 60 - 6F |
There are currently no valid POST codes in the 60 - 6F range.
If you see a POST code in this range, it should be read as B0 - BF. (On a 7-segment LED display, the 'b' looks like a 6).
Example:
 |
| 70 - 7F |
Output Devices |
| 70 |
Resetting the VGA controller |
| 71 |
Disabling the VGA controller |
| 72 |
Enabling the VGA controller |
| 78 |
Resetting the console controller |
| 79 |
Disabling the console controller |
| 7A |
Enabling the console controller |
| 7F |
Unrecoverable output device error |
| 90 - 9F |
Input Devices |
| 90 |
Resetting keyboard |
| 91 |
Disabling keyboard |
| 92 |
Detecting presence of keyboard |
| 93 |
Enabling the keyboard |
| 94 |
Clearing keyboard input buffer |
| 95 |
Instructing keyboard controller to run Self Test (PS2 only) |
| 98 |
Resetting mouse |
| 99 |
Disabling mouse |
| 9A |
Detecting presence of mouse |
| 9B |
Enabling mouse |
| 9F |
Unrecoverable input device (keyboard or mouse) error |
| B0 - BF |
Boot Devices |
| B0 |
Resetting fixed media |
| B1 |
Disabling fixed media |
| B2 |
Detecting presence of a fixed media (IDE hard drive detection etc.) |
| B3 |
Enabling/configuring a fixed media |
| B8 |
Resetting removable media |
| B9 |
Disabling removable media |
| BA |
Detecting presence of a removable media (IDE, CD-ROM detection, etc.) |
| BC |
Enabling/configuring a removable media |
| BF |
Unrecoverable boot device error |
| D0 - DF |
Boot Device Selection |
| Dy |
Trying boot selection y (y=0 to 15) |
| E0 - FF |
Miscellaneous Codes |
| E0 |
Started dispatching PEIMs (emitted on first report of EFI_SW_PC_INIT_BEGIN EFI_SW_PEI_PC_HANDOFF_TO_NEXT) |
| E2 |
Permanent memory found |
| E1, E3 |
Reserved for PEI/PEIMs |
| E4 |
Entered DXE phase |
| E5 |
Started dispatching drivers |
| E6 |
Started connecting drivers |
| E7 |
Waiting for user input |
| E8 |
Checking password |
| E9 |
Entering BIOS setup |
| EB |
Calling Legacy Option ROMs |
| EF |
Boot/S3 resume failure |
| F4 |
Entering Sleep state |
| F5 |
Exiting Sleep state |
| F8 |
EFI boot service ExitBootServices ( ) has been called |
| F9 |
EFI runtime service SetVirtualAddressMap ( ) has been called |
| FA |
EFI runtime service ResetSystem ( ) has been called |
| FF |
Processor exception |