In fact I never saw in 16 years a cable modem manufacturer provide a regular bootloader upgrade for the field. In compare to the normal single image which includes the normal firmware the bootloader is not using different partitions. So if the upgrade gets bad e.g. due power outage, the cable modem is a brick. If this happens due an upgrade with the normal firmware the cable modem bootloader make a checksum test during the bootup and can fallback to the old firmware.
We did make bootloader updates in our lab already but only with strong support of the manufacturer and manually by hand and only on the first lab samples.
Another possibility to upgrade the bootloader is to flash the right bootloader on the SPI chip but this is also a "complicated" situation. Nothing what scales in the field.
Why did you came to the conclusion that you need a new bootloader?
We have a lot of used modems returned by customers. Some of them don't load FW at all, they are completely bricked, so I think that bootloader is damaged. Some modems have old bootloaders version (I assume the last is PSPU-Boot 1.0.0.4m1)
Yes, the bootloader update procedures is completely vendor specific, and Docsis spec does not defines anything, related to boot loader update method.
Well, it seems that the SB6120 was a nice model for installing alternate firmwares like Forceware and maybe your customers did make mistakes with the update. To be sure you can try to get some output from the TTL interface or from the flash due a SOIC clip and SPI reader. So maybe it'll work that you make a copy from a good SB6120 bootloader and use them on the bricked cable modem. The bigger problem is if the content of the flash is totally lost including the cable modems NVRAM with its private/public key and CM-Certificate.
OK, flashing bootloader into bricked modems will be tedious and time consuming task. So it's easier just to recycle them. Updating bootloader in working devices can be done via serial interface, that much easier.
What are you trying to achieve?
Are you the cable operator, or an end user?
The cable operator controls the firmware on a cable modem
cable operator. I want update Bootloader to the latest version.
In fact I never saw in 16 years a cable modem manufacturer provide a regular bootloader upgrade for the field. In compare to the normal single image which includes the normal firmware the bootloader is not using different partitions. So if the upgrade gets bad e.g. due power outage, the cable modem is a brick. If this happens due an upgrade with the normal firmware the cable modem bootloader make a checksum test during the bootup and can fallback to the old firmware.
We did make bootloader updates in our lab already but only with strong support of the manufacturer and manually by hand and only on the first lab samples.
Another possibility to upgrade the bootloader is to flash the right bootloader on the SPI chip but this is also a "complicated" situation. Nothing what scales in the field.
Why did you came to the conclusion that you need a new bootloader?
We have a lot of used modems returned by customers. Some of them don't load FW at all, they are completely bricked, so I think that bootloader is damaged. Some modems have old bootloaders version (I assume the last is PSPU-Boot 1.0.0.4m1)
Yes, the bootloader update procedures is completely vendor specific, and Docsis spec does not defines anything, related to boot loader update method.
Well, it seems that the SB6120 was a nice model for installing alternate firmwares like Forceware and maybe your customers did make mistakes with the update. To be sure you can try to get some output from the TTL interface or from the flash due a SOIC clip and SPI reader. So maybe it'll work that you make a copy from a good SB6120 bootloader and use them on the bricked cable modem. The bigger problem is if the content of the flash is totally lost including the cable modems NVRAM with its private/public key and CM-Certificate.
OK, flashing bootloader into bricked modems will be tedious and time consuming task. So it's easier just to recycle them. Updating bootloader in working devices can be done via serial interface, that much easier.