annoying panic on boot

[Daniel Braniss]

Stopped at      vga_bitblt_one_text_pixels_block+0x13e: movl    (%rax,%r13,4),%d
db> bt    
Tracing pid 4 tid 100090 td 0xfffff8000c522620
vga_bitblt_one_text_pixels_block() at vga_bitblt_one_text_pixels_block+0x13e/fr0
vga_bitblt_text() at vga_bitblt_text+0xc0/frame 0xfffffe00002d5160
vt_flush() at vt_flush+0x38f/frame 0xfffffe00002d51b0
termcn_cnputc() at termcn_cnputc+0xbe/frame 0xfffffe00002d51e0
cnputc() at cnputc+0x181/frame 0xfffffe00002d5210
cnputs() at cnputs+0x78/frame 0xfffffe00002d5230
putchar() at putchar+0x14d/frame 0xfffffe00002d52b0
kvprintf() at kvprintf+0x113d/frame 0xfffffe00002d53b0
vprintf() at vprintf+0x84/frame 0xfffffe00002d5500
printf() at printf+0x43/frame 0xfffffe00002d5560
cddone() at cddone+0x210/frame 0xfffffe00002d5b20
xpt_done_process() at xpt_done_process+0x697/frame 0xfffffe00002d5b60
xpt_done_td() at xpt_done_td+0x196/frame 0xfffffe00002d5bb0
fork_exit() at fork_exit+0x82/frame 0xfffffe00002d5bf0
fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe00002d5bf0
--- trap 0, rip = 0, rsp = 0, rbp = 0 —

the above happens on boot, sometimes, the host is a dell PowerEdge R710 running very resent stable,
any help?

thanks,
	danny