Specifications

BMC Flash Update QSSC-S4R Technical Product Specification
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Firmware Transfer commands allow any area of the BMC flash to be updated. These functions understand the sector
structure of the flash device used on the server board, so the update utility cannot issue sector erase commands.
Instead flash sectors are implicitly erased as necessary before the first write to a sector.
After the Exit Firmware Transfer Mode command is successfully completed, the BMC resets, and the new image runs
immediately after the bootloader boots the BMC. If there is a problem booting the new image, such as an invalid
checksum, the BMC stays in the boot block. For more information refer to the Boot Recovery mode section.
No system events are logged when the BMC enters or exits firmware transfer mode.
26.2.1 Command Support During Firmware Transfer Mode
The following commands are supported while the BMC is in forced-firmware update mode. See section 26.3 for more
information on this mode.
Table 201. Firmware Update Mode Commands
IPMI NetFunction Command Number Command Name
Application (06h) 01h Get Device ID
Application (06h) 04h Get Self Test Results
Application (06h) 37h Get System GUID
Firmware (08h) 00h Enter Firmware Transfer Mode
Firmware (08h) 01h Firmware Program
Firmware (08h) 02h Firmware Read
Firmware (08h) 03h Get Firmware Range Checksum
Firmware (08h) 04h Exit Firmware Transfer Mode
Firmware (08h) 05h Set Program Segment
Stora
g
e
(
0Ah
)
10h Get FRU Area Info
Intel General (30h) 66h Get Buffer Size
Intel General
(
30h
)
71h Get Advanced Support Confi
g
uration
During a standard firmware update, the BMC will respond normally to all IPMI commands. However, the BMC will not
respond to commands for the 15 seconds after exiting firmware update mode (either normal or force-update) while it
reboots.
26.3 Boot Recovery Mode
The BMC’s boot block (Uboot) also supports firmware transfer updates. It uses the same commands as the operational
Firmware Transfer mode, but writes directly to the flash. Operational Firmware Transfer mode preserves several of the
files in the PIA Linux file system. Boot Recovery mode cannot preserve the files because it does not understand Linux
file systems, and treats it as a large binary data section. This means a Boot Recovery update completely replaces the
PIA with the factory default version: an empty SEL, a default SDR, and default IPMI configuration and user settings.
Boot Recovery mode can successfully complete an update in some situations where the Operational Firmware
Transfer mode will fail. If there is an incompatibility or bug in the operational code causing it to crash or hang, only a
Boot Recovery Mode Update will work. Another example is if the flash layout of the sections change across an update.
Since the operational Firmware Transfer mode tries to preserve the contents of the PIA section, in this case it will
corrupt the flash where the old PIA section was. Because the Boot Recovery mode is blindly writing binary data to
flash, in this case it will succeed.
Note: The flash layout should never change in a field update.
There are two ways to enter Boot Recovery mode:
x The Force Firmware Update jumper is asserted when A/C power is applied.
x The operational code is corrupt and the boot loader cannot boot.
In Boot Recovery mode the BMC only responds to the small set of commands listed above. Only the KCS SMS
interface is supported. USB-based Fast Firmware Update is not supported.
26.4 Force Firmware Update Jumper
The Force Firmware Update jumper can be used to put the BMC in Boot Recovery mode for a low level update. It
causes the BMC to abort its normal boot process and stay in the boot loader without executing any Linux code.