I have just rebooted from a 2.6.35 kernel to 18.104.22.168 in order to have the ability to hibernate bluecore with Tux-on-Ice again. However, the laptop acted up after the warm reboot as a consequence of running Linux in KMS operation mode, apparently. The greatest sign of doom: the Giant Blinking Cursor of Doom.
It’s normal for these HP laptops to display the text-mode blinking cursor for a bit after the BIOS splash screen, right before transferring execution to the first available boot medium. The cursor’s size is similar to Linux’s or MS-DOS under a default configuration with any generic VGA-compatible video adapter. In this transition state, the bold-white cursor blinks a few times at the top-left corner of the empty black screen, before changing its color to the normal text terminal white when GNU GRUB takes over.
However, whenever the AMD ATI Catalyst drivers lock up the laptop and I perform a warm reboot using one of the Magic SysRq sequences, the laptop doesn’t get past the system initialization code and after the BIOS splash screen disappears, instead of the usual bright blinking cursor, an abnormally large and wide white blinking cursor appears as the computer gets stuck forever.
I had not seen this occur after running with the open-source KMS drivers before, but I guess it might indicate I own a faulty GPU or motherboard.
EDIT: now I have pictures — taken with my three years old cell phone — showing the normal blinking cursor and the GBCoD: