On Fri, 22 Apr 2011 19:45:21 +0600 Roman Mamedov <r...@romanrm.ru> wrote:
> - The Fuloong (PMON LM6004-1.3.6) when powered on displays the SiS video card > BIOS message, then after a long delay (maybe 10 seconds) it shows the full > screen Lemote logo; then after some seconds it gets to the PMON boot menu. > Looks like it works a lot slower than with its 512MB stick. > Then I select a kernel to boot (2.6.38.3), menu disappears, the HDD led > lights up for 2-3 seconds, then the LED turns off and nothing else happens > (no more LED activity, blank screen). Hello, I did some more experiments, and here's what I found so far. 1) PMON LM6004-1.3.6 does report all the RAM. It sets memsize=256, highmemsize=3712, and shows 4 GB in the "BIOS setup" called via "main". 2) Starting memory test in PMON via "mt" runs for considerable time with no errors. 3) Starting the "newmt" memory test fails immediately with a "TLB miss on store" error: http://romanrm.ru/pics/2011/2011-04-22-fuloong-4gb-memtest.jpg 4) I managed to have the kernel start booting, by issuing "highmemsize=256" (or even 768) in PMON, then loading the kernel. But it fails very early at boot, it is tricky to read the messages there, but at first it's "IRQ 14: nobody cared", then "Unable to handle kernel paging request". I may try netconsole a bit later, though not sure if it will work this early at boot. 5) Even when the kernel starts booting in the above manner, it is SLOW - I can see how the text redraws and scrolls. So it confirms the delays before PMON, with 4GB installed the machine (or the video card) runs very slowly for some reason. I do not think it is an electrical-level problem, because the above behavior is completely consistent (everything happens 100% reproducible). My wild guess: PMON cannot properly do a complete initialization of hardware (IRQ, DMA?) because it is confused by this much system RAM. Maybe it can't map some I/O area into below 4GB, when there are actual 4GB of RAM present? I have noticed there is a 64-bit PMON branch available in the git repository - how do I check if my PMONs are already compiled to 64-bit? I need to decide pretty soon if I am going to return this memory stick to the shop, so if anyone has ideas to try, don't hesitate to post ideas over this couple of days... I think it'd be quite useful to find and fix the problem with 4GB of RAM rather than just giving up on it, especially since it "almost works". -- With respect, Roman
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