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requesting mappings from sigma0
by Kermit the Frog 22 Dec '99

22 Dec '99

Hello, Ive been having some problems while trying to request a page from sigma0. I have included the source code ... any help ? many thanks! ------[ source begins here ]------ #include <l4/types.h> #include <l4/syscalls.h> #include <l4/ipc.h> #include <stdio.h> #define SIGMA0_ID 4 void main(void) { l4_threadid_t sigma0; l4_msgdope_t msg, result; dword_t addr, type, foo, *r_add; addr = 0x80000; type = L4_IPC_SHORT_MSG; sigma0.id.task = SIGMA0_ID; sigma0.id.lthread = 0; r_add = 0x0; while(r_add == 0x0) { addr += 4096; /* pasamos a la siguiente pagina de 4K */ printf("Vamos a pedir la region de memoria 0x%x\n", addr); l4_i386_ipc_send(sigma0,(void *) type, addr, addr, L4_IPC_NEVER, &result); printf("ipc enviado ..."); l4_i386_ipc_receive(sigma0, L4_IPC_MAPMSG(addr, 4096), r_add, &foo, L4_IPC_NEVER, &result); printf("%p recivido\n", r_add); } *r_add = 'a'; r_add++; *r_add = 0x7; r_add --; if(*r_add == 'a') printf("BINGO!\n"); printf("Done!\n"); } Cervi~no Ulises <kermit(a)tower.com.ar> <ulises(a)rosario.linux.org.ar> ............................................................................... "Contrary to popular opinion, Unix is user friendly, It just happens to be very selective about who it makes friends with."

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Fiasco & oskit10
by Christian Stueble 21 Dec '99

21 Dec '99

Is it possible to compile fiasco based on oskit10? I think there are some files missing (flux/*/*)?? When compiling l4/pkg/oskit_support/lib/src/ I get an error message: --- ... Making rmgr_stubs.o {standard input}: Assembler messages: {standard input}: Error: Symbol 'rmgr_pager_id' can not be both weak and common --- If I remove '__attribute__ ((weak))' it works. Is this a bug? I use egcs-2.91.66. -Chris- -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Christian Stueble............stueble(a)ls6.cs.uni-dortmund.de PubKey[BF7104F5].......fp=8678C5D3CAD9CD8C F1DDB8EC202F116A To be or not to be is true... (apocrypha of George Boole) -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

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Using g++ to compile hello?
by Christian Stueble 21 Nov '99

21 Nov '99

Hi! Is it possible to compile the test program ŽhelloŽ using the g++ compiler. I get an error message 1) main.cpp:37: undefined reference to `__throw' ...if I link main.o and crt0.o with the ld linker, and 2) crt0.o(.text+0x0): multiple definition of `_start' /usr/lib/crt1.o(.text+0x0): first defined here ...if I try to link the files with g++ -o xxxx. Can somebody help me? Chris -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Christian Stueble............stueble(a)ls6.cs.uni-dortmund.de PubKey[BF7104F5].......fp=8678C5D3CAD9CD8C F1DDB8EC202F116A To be or not to be is true... (apocrypha of George Boole) -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

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Apologies for mispost
by Gernot Heiser 18 Nov '99

18 Nov '99

My last two messages were not meant for l4-hackerßos.inf.tu-dresden.de, but for one of our internal lists. Apologies, Gernot-- Gernot Heiser ,--_|\ School of Computer Sci. & Engin. Phone: +61 2 9385 5156 / \ The University of NSW Fax: +61 2 9385 5995 \_,--._* Sydney, Australia 2052 E-mail: gernot(a)unsw.edu.au v http://www.cse.unsw.edu.au/~gernot PGP fingerprint: 94 1E B8 28 25 FD 7C 94 20 10 92 E5 0B FF 39 8F

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Re: L4 Workshop papers
by Gernot Heiser 18 Nov '99

18 Nov '99

------- Blind-Carbon-Copy From: Gernot Heiser <gernot(a)cse.unsw.edu.au> To: jaegert(a)us.ibm.com cc: Liedtke(a)ira.uka.de, Haertig(a)os.inf.tu-dresden.de, hohmuth(a)innocent.com Subject: Re: L4 Workshop papers In-reply-to: Your message of "Thu, 18 Nov 1999 10:03:10 CDT." <8525682D.0052B697.00(a)D51MTA03.pok.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Reply-to: "Gernot Heiser" <gernot> Date: Fri, 19 Nov 1999 08:04:33 +1100 Sender: gernot(a)zuse.disy.cse.unsw.EDU.AU Thanks, Trent. I really have material for a number of talks, but don't see how I can find the time to write up anything before the 1st (and the students are studying for their exams). Topics: - - StrongARM kernel - - API extensions for SMP scheduling and cacheability - - SMP Alpha kernel - - supporting multiple page sizes - - portable VM implementation? Another problem is that I still haven't got a return flight. I may have to get a business class flight (which means paying the difference out of my own pocket) to be able to make it. Gernot - -- Gernot Heiser ,--_|\ School of Computer Sci. & Engin. Phone: +61 2 9385 5156 / \ The University of NSW Fax: +61 2 9385 5995 \_,--._* Sydney, Australia 2052 E-mail: gernot(a)unsw.edu.au v http://www.cse.unsw.edu.au/~gernot PGP fingerprint: 94 1E B8 28 25 FD 7C 94 20 10 92 E5 0B FF 39 8F ------- End of Blind-Carbon-Copy

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Re: RMGR-Extension to control I/O access
by Michael Hohmuth 22 Oct '99

22 Oct '99

Christian Stueble <stueble(a)amaunet.cs.uni-dortmund.de> writes: > > That is exactly what io flex pages are designed for. Initially sigma0 > > has access to all io ports and can use io flex pages to grant port > > access to other task. If sigma0 grants access a subset of the io > > address space (adressses which are accessed by in/out instructions) > > the task gets an io permission bitmap. If sigma0 (or someone else) > > grants access to the whole io address space l4 changes the iopl so > > that any thread in this task can access any port and can even disable > > interrupts. > I understand the x86 manual in that way: i/o access is permitted only if the > tasks CPL <= IOPL _and_ if appropriated bits are set to 0. No, that´s ``or,´´ not ``and.´´ > Generally, only two new IPC messages (to the RMGR or sigma0?) are > necessary: Rmgr > 1) demandPort( port_nr, size ) > 2) releasePort( port_nr, size ) Yes, that´s right. > Does someone know, why the l4 reference manual restricts the granularity of > port access to 16 byte? No, I don´t. Maybe Jochen can shed some light on this? Michael -- hohmuth(a)innocent.com, hohmuth(a)sax.de http://www.sax.de/~hohmuth/

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Error msg: in space.cc
by Christian Stueble 21 Oct '99

21 Oct '99

Hi, if I boot Fiasco (Mar 31 1999) on my i486 machine, I get the following error message: ---- SIGMA0: Hello! i am 80000:40000, my pager is 0:0 RMGR: Hi there! RMGR: running on L4/Pentium space.cc:179: failed assertion 'size == PAGE_SIZE' ---- What does it mean? Does Fiasco only run on a Pentium machine? Chris -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Christian Stueble............stueble(a)ls6.cs.uni-dortmund.de PubKey[BF7104F5].......fp=8678C5D3CAD9CD8C F1DDB8EC202F116A To be or not to be is true... (apocrypha of George Boole) -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

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Re: Question about IO-fpages
by Michael Hohmuth 21 Oct '99

21 Oct '99

Christian Stueble <stueble(a)amaunet.cs.uni-dortmund.de> writes: > I think Fiasco/L4 uses memory mapped I/O, not separated I/O? Memory-mapped I/O (that is, I/O via memory accesses in the virtual address space) and I/O via the separate 16-bit I/O address space (with in/out instructions; ``port I/O'') are completely separate from each other. It is not possible to map the port address space into the virtual memory, and that means it is not possible to replace port I/O with memory-mapped I/O. That's why, the kernel needs to support port I/O. Michael -- hohmuth(a)innocent.com, hohmuth(a)inf.tu-dresden.de http://home.pages.de/~hohmuth/

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A few questions
by Geoff Humphreys 20 Oct '99

20 Oct '99

Hello. I have been writing my own microkernel using ideas from L4 and other kernels. I am curious as to whether or not there would be an appreciable performance increase if the L4 system calls were split up into multiple calls. For example, the IPC call is be used to send messages, recieve messages, and to do RPC. Wouldn't it be faster if each of those were separate system calls (since it would require less if-then logic and bit manipulation)? Is there any reason not to do this? In addition, I am seeking well-commented, easy to understand scheduling algorithms or detailed descriptions of them. Right now I am using a nice, simple round-robin scheduler that doesn't even take priorities into account. It is very efficient, however. 8-) Also, does L4 have any support for semaphores? I was unable to find anything in the documentation. Thanks Geoff ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com

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Re: A few questions
by Jean Wolter 20 Oct '99

20 Oct '99

"Geoff Humphreys" <xsaber0(a)hotmail.com> writes: > > Hello. I have been writing my own microkernel using ideas from L4 and other > kernels. > > I am curious as to whether or not there would be an appreciable performance > increase if the L4 system calls were split up into multiple calls. For > example, the IPC call is be used to send messages, recieve messages, and to > do RPC. Wouldn't it be faster if each of those were separate system calls > (since it would require less if-then logic and bit manipulation)? Is there > any reason not to do this? Maybe you should have a look at Jochen's micro kernel papers on our L4 page (SOSP93, SOSP95). One point was to combine the various ipc operations into one system call to reduce the number of 'kernel boundary crossings'. You add one simple if and remove an expensive switch from user to kernel and back. So this actually increases performance. > Also, does L4 have any support for semaphores? I was unable to find > anything in the documentation. There are no semaphores inside L4. All semaphores are implemented on user level. Jean -- I get up each morning, gather my wits. Pick up the paper, read the obits. if I'm not there I know I'm not dead. So I eat a good breakfast and go back to bed. Peete Seeger

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