I try to send this message again, since it seems it has not been posted:
Hi all - I have some questions; I hope they have not already been posed!
- I'm running a bare qemu + pistachio 0.4, and its kickstart + sigma0, with a little root server of my own, on a IA32 architecture. I ask for bootinfo location, and I find it's 0x1000 (that's where kickstart puts it, so it's ok). However, when I try accessing it, I obviously pagefault, but sigma0 refuses to give me that page. Anyway, if I _force_ it it to do (I've tweaked by hand source code), everything works fine - in fact the bootinfo is there, and it is correct. Did I get something wrong?
- Little note: looking kickstart, I found this, around user/util/kickstart/mbi-loader.cc:486:
if (use_bootinfo) { // Allocate and initialize a bootinfo structure. bi = init_bootinfo (&kip); rec = (L4_BootRec_t *) ((L4_Word_t) bi + bi->size);
if (bi) // Record MBI modules rec = record_bootinfo_modules (bi, rec); else use_bootinfo = false; }
(I'm referring to CVS version, If I remember well 0.4 version was exactly the same). The "rec = stuff" isn't wrong? If "bi" is set to NULL by the init_bootinfo (in case of OOM, if I remember well), this segfaults - well, don't know what it does exactly, since there's still no kernel around, and I don't remember IA32 defaults ;D
- Looking L4 specs (even the latest - by the way, how come the sources theirselves aren't published? I would have found it useful when I did those searches about sigma0 ;D), I have found no satisfying explanation about the kinds of memory descriptors L4 knows about. That is, UndefinedMemoryType, BootLoaderSpecificMemoryType, ArchitectureSpecificMemoryType are obvious, but what are the differences between ConventionalMemoryType and SharedMemoryType? What between ReservedMemoryType and DedicatedMemoryType? What are their exact meanings? Not that I absolutely need to work this out now, but I would like to know this better! :-)
- Last: what purpose sigma1 has? I remember reading something about it in the papers about transparent checkouts of kernel state, and stuff like that...
Thank you all for the attention! :-)
l4-hackers@os.inf.tu-dresden.de