Current Page -
Last modified Thu Apr 28 00:26:45 EDT 2005
5/5/2003 What we're going to put in here now is the update of how the system works now. The base test hardware is the PCM-5923 from Advantech. We built a standard LinuxBIOS for this board that uses Etherboot to load the 9load image from Compact Flash. I can send you the flash ROMIMAGE on request so that rather than fool around with LinuxBIOS you can just use our image.
We've had to make fixes to 9load and we are now trying to back those changes out as much as possible to minimize 9load variance.
The parts you need to replicate our setup:
If you just the flash image from us, we can also send the working 9load image (which you burn onto the CF) and a working Plan 9 kernel image which you tftp download. This kernel knows how to use CMOS for its nvram.
Base document follows:
LinuxBIOS can load lots of different "payloads", i.e. ELF images in FLASH. In this document we will go over how we got 9load into FLASH, and thus made nodes that can boot as dedicated Plan 9 CPU nodes.
NOTE: also check (http://www.acl.lanl.gov/plan9/flash/(broken link!)) for additional information!
This documentation pertains to the setup, configuration and means of getting Plan 9 booted with LinuxBIOS. It consists of the following parts:
This document discusses changes made to the source of Plan9 to get it going on at least one machine booted by LinuxBIOS. The goal of the project was to have a standalone Plan9 cpu server that neither had nor required moving parts. Most of this was accomplished with the help of Ron Minnich, without whose support and in-depth knowledge of computer hardware minions would still be scratching their head trying to find out why nothing happens after the kernel is downloaded...
For a succesfull modification to the source one needs to have access to the following:
Plan9 setup:
The setup for P9 uses the fact that the operating system supports union directories. What that gives us is the ability to store only those files we modify in our local directory, and bind them when necessary on top of the standard kernel tree (in /sys/src/)... In fact this results in a carefully crafted namespace that could be used in a single terminal window (or, if so willing in an entire rio session on a cpu server) to present a decent development environment, while the rest of the screen, session or terminals keep the common, non-development view of the system. Ultimately this allows for several different developments to go on at the same time, (example will be shown in a bit) -- compiling kernels in one window, 9load bootloaders in another window, while being able to see the normal, unmodified kernel tree in a third window for comparison. All in the same directory.
How it actually works:
In brief, LinuxBIOS starts up on the hardware, find and loads Plan9's bootloader (9load masked as an elf32 image so it can be recognized by LinuxBIOS), 9load then prompts for kernel or attempts to etherboot one, downloads it, uncompresses it and jumps to it. Voila.
Details follow:
You compile (make) a 9load image tailored to work with
LinuxBIOS:
p9% lbbind # bind the development tree... p9% mk 9loadlb # in the mkfile there's a special 8a -DLinuxBios -o ll.8 l.s # configuration for linuxbios 8c -FVw -I. alarm.c # kernels carrying the necessary 8c -FVw -I. cga.c # #define's and linking 9load 8c -FVw -I. clock.c # at 0x800000 8c -FVw -I. console.c 8c -FVw -I. dosboot.c 8c -FVw -I. donprint.c 8c -FVw -I. devfloppy.c 8c -FVw -I. dma.c 8c -FVw -I. ilock.c 8c -FVw -I. kbd.c 8c -FVw -I. queue.c 8c -FVw -I. trap.c 8c -FVw -I. 8250.c warning: 8250.c:130 param declared and not used: arg 8c -FVw -I. apm.c 8c -FVw -I. boot.c 8c -FVw -I. devpccard.c 8c -FVw -I. conf.c 8c -FVw -I. devi82365.c 8c -FVw -I. devsd.c 8c -FVw -I. inflate.c 8c -FVw -I. load.c warning: load.c:159 no return at end of function: myboot load.c:280 function args not checked: pcihinv 8c -FVw -I. memory.c 8c -FVw -I. part.c 8c -FVw -I. pci.c 8c -FVw -I. sdata.c 8c -FVw -I. sdmylex.c 8c -FVw -I. sd53c8xx.c 8c -FVw -I. sdscsi.c 8c -FVw -I. bootp.c 8c -FVw -I. ether.c 8c -FVw -I. ether2114x.c 8c -FVw -I. ether2000.c 8c -FVw -I. ether589.c 8c -FVw -I. ether79c970.c 8c -FVw -I. ether8003.c 8c -FVw -I. ether8139.c 8c -FVw -I. ether82557.c 8c -FVw -I. ether83815.c 8c -FVw -I. ether8390.c 8c -FVw -I. etherec2t.c 8c -FVw -I. etherelnk3.c 8l -o 9loadlb -H3 -T0x80800000 -l ll.8 alarm.8 cga.8 clock.8 console.8 dosboot.8 donprint.8 devfloppy.8 dma.8 ilock.8 kbd.8 queue.8 trap.8 8250.8 apm.8 boot.8 devpccard.8 conf.8 devi82365.8 devsd.8 inflate.8 load.8 memory.8 part.8 pci.8 sdata.8 sdmylex.8 sd53c8xx.8 sdscsi.8 bootp.8 ether.8 ether2114x.8 ether2000.8 ether589.8 ether79c970.8 ether8003.8 ether8139.8 ether82557.8 ether83815.8 ether8390.8 etherec2t.8 etherelnk3.8 -lflate -lc ls -l 9loadlb --rwxr-xr-x M 9 andrey andrey 178320 Jun 20 11:34 9loadlb p9% 9loadlb is a special configuration in the mkfile that will #define 'LinuxBios' during the compilation and will link 9loadlb at 0x800000 (that's where LinuxBIOS will jump to). Next step is to copy 9loadlb to the linux machine (usually you would scp it a level below the mkelf/ directory in snaresland): fbsd$ scp plan9:src/boot/pc/9loadlb ../9load.800000 andrey@plan9.acl.lanl.gov's password: 9loadlb 100% |*****************************| 174 KB 00:00 fbsd$
Then run the 'mymk' script in mkelf:
snares$ pwd /users/andrey/kern/mkelf snares$ ./mymk #!/bin/sh -v cd 9load cp ~/kern/9load.800000 . make all4 ./mkas < 9load.800000 > 9l.s as -o 9l.o 9l.s ld -T elfImage.lds.800000 -o 9l.elf 9l.o ld: warning: cannot find entry symbol startup_32; defaulting to 00800000 cp 9l.elf .. cd .. bin/mkelfImage --kernel=9l.elf Running gcc -O2 -DDEFAULT_ROOT_DEV='(((0x3<<8)| 0))' -DDEFAULT_COMMAND_LINE='""' -DDEFAULT_PROGRAM_VERSION='""' -c /users/andrey/kern/mkelf/share/mkelfImage/elf32-i386/convert_params.c -o /am/mother-v2-e5/vol/vol0/u0/andrey/kern/mkelf/convert_params_6384.o Running gcc -O2 -DDEFAULT_ROOT_DEV='(((0x3<<8)| 0))' -DDEFAULT_COMMAND_LINE='""' -DDEFAULT_PROGRAM_VERSION='""' -c /users/andrey/kern/mkelf/share/mkelfImage/elf32-i386/head.S -o /am/mother-v2-e5/vol/vol0/u0/andrey/kern/mkelf/head_6384.o Running ld -o elfImage.fat -T /users/andrey/kern/mkelf/share/mkelfImage/elf32-i386/elfImage.lds /am/mother-v2-e5/vol/vol0/u0/andrey/kern/mkelf/kernel_piggy_6384.o /am/mother-v2-e5/vol/vol0/u0/andrey/kern/mkelf/ramdisk_piggy_6384.o /am/mother-v2-e5/vol/vol0/u0/andrey/kern/mkelf/convert_params_6384.o /am/mother-v2-e5/vol/vol0/u0/andrey/kern/mkelf/head_6384.o Running ld -o elfImage.fat -T /users/andrey/kern/mkelf/share/mkelfImage/elf32-i386/elfImage.lds /am/mother-v2-e5/vol/vol0/u0/andrey/kern/mkelf/kernel_piggy_6384.o /am/mother-v2-e5/vol/vol0/u0/andrey/kern/mkelf/ramdisk_piggy_6384.o /am/mother-v2-e5/vol/vol0/u0/andrey/kern/mkelf/convert_params_6384.o /am/mother-v2-e5/vol/vol0/u0/andrey/kern/mkelf/head_6384.oBFD: elfImage.fat: warning: Empty loadable segment detected checksum: dc7c echo done done
The script is a bit ugly, but we strive not for beauty... You'll find it below, or in the linux bundle... Next step is to scp back the 9load (masked as an elfImage) to a place where it could be burned in flash, or if you want to debug, downloaded by an etherboot LinuxBIOS:
fbsd$ scp elfImage plan9:/386/9pcblah andrey@plan9.acl.lanl.gov's password: elfImage 100% |*****************************| 190 KB 00:00 scp: can't wstat /386/9pcblah: wstat -- attempt to change qid.vers fbsd$
Ignore the error message if you see it... In this case, the dhcp server has been instructed to provide /386/9pcblah as the kernel to a bootp request from the machine we work with (based on that machine's ethernet address, ask dpx@acl for more details).
NOTE: if you think that the 9load will work fine, just tell Ron to burn it in flash for you.. In this case you need to put the 9pccpu kernel in /386/9pcblah instead :)
File organization:
create a $home/src directory to store all the modified files in. the then in $home/src recreate all the directories present in /sys/src, which pertain in your current development. in my case it was /sys/src/9, /sys/src/boot, /sys/src/libauthconfig, and then recursively recreate all other directories present there. here's a real-life example:
p9% du /usr/andrey/src | awk '{print $2}'
/usr/andrey/src/9/pc
/usr/andrey/src/9/ip
/usr/andrey/src/9/alphapc
/usr/andrey/src/9/bitsy
/usr/andrey/src/9/boot
/usr/andrey/src/9/port
/usr/andrey/src/9/mtx
/usr/andrey/src/9
/usr/andrey/src/libauthsrv
/usr/andrey/src/boot/alphapc
/usr/andrey/src/boot/arm
/usr/andrey/src/boot/pc
/usr/andrey/src/boot
/usr/andrey/src/cmd/aux/vga
/usr/andrey/src/cmd/aux
/usr/andrey/src/cmd/auth/factotum
/usr/andrey/src/cmd/auth/lib
/usr/andrey/src/cmd/auth/secstore
/usr/andrey/src/cmd/auth
/usr/andrey/src/cmd
/usr/andrey/src
p9%
Then if you want to edit /sys/src/9/pc/pci.c just do:
cp /sys/src/9/pc/pci.c $home/src/9/pc/pci.c
Scripts:
Several scripts are used to automate the binding process and to make your life easier. Remember that after the boot-up the machine is in a non-development state, i.e. it does not know that you have made any modification to the kernel source -- you have to tell it to change the namespace accordingly, so that when you type 'mk' in /sys/src/9/pc it will compile your own files instead of somebody else's... The scripts will do the modification to the namespace for you, just execute them before you start working on the code (think of it as a 'start your engines' of some sort). Here are the scripts (they differ because one does binding of the $home/src/9 as the kernel tree -- something I use for writing drivers to support several graphics cards, i.e. non-LinuxBIOS kernels) and the other binds $home/src/linuxbios/ which is the same as $home/src/9, but the files therein are LinuxBIOS-related. Copy those files in $home/bin/rc and chmod 755 them:
p9% cat /usr/andrey/bin/rc/kbind #!/bin/rc # this does bindings for the non-linuxbios kernel sources # and the 9load linuxbios sources # 9 bind -cb $home/src/9/pc /sys/src/9/pc bind -cb $home/src/9/ip /sys/src/9/ip bind -cb $home/src/9/alphapc /sys/src/9/alphapc bind -cb $home/src/9/bitsy /sys/src/9/bitsy bind -cb $home/src/9/boot /sys/src/9/boot bind -cb $home/src/9/port /sys/src/9/port bind -cb $home/src/9/mtx /sys/src/9/mtx #boot bind -cb $home/src/boot/alphapc /sys/src/boot/alphapc bind -cb $home/src/boot/arm /sys/src/boot/arm bind -cb $home/src/boot/pc /sys/src/boot/pc #fs bind -cb $home/src/fs/port /sys/src/fs/port bind -cb $home/src/fs/choline /sys/src/fs/choline bind -cb $home/src/fs/dev /sys/src/fs/dev bind -cb $home/src/fs/emelie /sys/src/fs/emelie bind -cb $home/src/fs/ip /sys/src/fs/ip bind -cb $home/src/fs/pc /sys/src/fs/pc bind -cb $home/src/fs/roro /sys/src/fs/roro bind -cb $home/src/fs/sony /sys/src/fs/sony #cmd bind -cb $home/src/cmd /sys/src/cmd p9%
The #cmd part is not really necessary, but i keep in there
stuff i do with P9 commands...
p9% cat /usr/andrey/bin/rc/lbbind #!/bin/rc # linuxbios stuff # 9 bind -cb $home/src/linuxbios/pc /sys/src/9/pc bind -cb $home/src/linuxbios/ip /sys/src/9/ip bind -cb $home/src/linuxbios/alphapc /sys/src/9/alphapc bind -cb $home/src/linuxbios/bitsy /sys/src/9/bitsy bind -cb $home/src/linuxbios/boot /sys/src/9/boot bind -cb $home/src/linuxbios/port /sys/src/9/port bind -cb $home/src/linuxbios/mtx /sys/src/9/mtx #boot bind -cb $home/src/boot/alphapc /sys/src/boot/alphapc bind -cb $home/src/boot/arm /sys/src/boot/arm bind -cb $home/src/boot/pc /sys/src/boot/pc #fs bind -cb $home/src/fs/port /sys/src/fs/port bind -cb $home/src/fs/choline /sys/src/fs/choline bind -cb $home/src/fs/dev /sys/src/fs/dev bind -cb $home/src/fs/emelie /sys/src/fs/emelie bind -cb $home/src/fs/ip /sys/src/fs/ip bind -cb $home/src/fs/pc /sys/src/fs/pc bind -cb $home/src/fs/roro /sys/src/fs/roro bind -cb $home/src/fs/sony /sys/src/fs/sony #cmd bind -cb $home/src/cmd /sys/src/cmd p9%
Actually, only the lbbind command is needed -- that'll bind
all sources from the source tree
An example of a typical P9 session follows:
p9% lbbind p9% cd /sys/src/9/pc # edit some files, make some changes, etc... #make a cpu kernel p9% mk 'CONF=pccpu' 8c -FVw ether79c970.c 8c -FVw vgabt485.c # lots of files being compiled, here's where your errors will happen # # now you have a decent kernel, copy it somewhere where it could be etherbooted p9% cp 9pccpu # clean up -- not really necessary, but sometimes fun :) p9% mk clean rm -f *.[v4586xq7] *.root.s cfs.h fs.h init.h conf.h *.out for(i in pc pccpu pcdisk) mk $i.clean rm -f pc.c [9bz]pc [9bz]pc.gz bootpc.* rm -f pccpu.c [9bz]pccpu [9bz]pccpu.gz bootpccpu.* rm -f pcdisk.c [9bz]pcdisk [9bz]pcdisk.gz bootpcdisk.* p9% # to stop a development session just delete the terminal window, # your files will be saved there :)
Here you'll need ron's help! CVS update the latest from the freebios distribution, then guntar the mkelf.tgz file included, then get Ron to make LinuxBIOS proper so you can combine it with 9loadlb... I pretty much know nothing about this process. As far as I am concerned I may as well be sitting around waving a chicket at the screen while Ron does everything... After the setup, just use the 'mymk' script as above and enjoy :)
/sys/src/boot/pc/mkfile -- the file was changed to accomodate my Plan9 endeavours. a new target was added, namely the 9loadlb linuxbios-enabled kernel. the difference is that the linuxbios code is #ifdef-ed LinuxBios:
p9% diff boot/pc/mkfile /sys/src/boot/pc/mkfile 7d6 < 9loadlb\ 95,98d93 < 9loadlb: ll.$O $CORE $LOAD $ETHER < $LD -o $target -H3 -T0x80800000 -l $prereq -lflate -lc < ls -l $target < 118,120d112 < < ll.$O: l.s < $AS -DLinuxBios -o ll.$O l.s p9%
/sys/src/boot/pc/l.s -- the real mode code is commented out (rather, ifdef'd), 9load is entered in protected mode. code is added to load the GDT. some attempts to fix the IRQ routing problem but nothing is tested extensively. we ended up chasing a bug for a long time with:
MOV AX, SS
and ended up fixing it somewhat miraculously. it never appears in normal bios boots...
stuff like:
MOVL $0x80, DX MOVB $0x19, AL OUTB
is simply outputting to the post card (ask Ron for details on Post-Card debugging! It's the most fun you can have without having to go outside and exercise!
diff:
p9% diff boot/pc/l.s /sys/src/boot/pc/l.s 20,24d19 < < MOVL $0x80, DX < MOVB $0x11, AL < OUTB < 27c22 < #ifndef LinuxBios --- > 200,202d194 < < < 209c201 < MOVL $1,AX --- > LWI(1, rAX) 213,216d204 < /* MOVL CR0,AX < ORL $1,AX < MOVL AX,CR0 < */ 227,238c215,218 < < #endif /* LinuxBios */ < /* begin andrey messing around */ < < MOVL $0x80, DX < MOVB $0x11, AL < OUTB < < MOVL tgdtptr-KZERO(SB),GDTR /**/ < < < MOVW $SELECTOR(1, SELGDT, 0),AX /**/ --- > /* MOVW $SELECTOR(1, SELGDT, 0),AX /**/ > BYTE $0xc7 > BYTE $0xc0 > WORD $SELECTOR(1, SELGDT, 0) 239a220 > MOVW AX,SS 243d223 < MOVW AX,SS 245,249d224 < MOVL $0x80, DX < MOVB $0x12, AL < OUTB < < #ifndef LinuxBios 255,256c230,231 < #endif /* linuxbios */ < TEXT mode32bit(SB),$0 --- > > TEXT mode32bit(SB),$0 266,270d240 < < MOVL $0x80, DX < MOVB $0x13, AL < OUTB < 274,277d243 < MOVL $0x80, DX < MOVB $0x14, AL < OUTB < 290,292d255 < < < 308d270 < 320d281 < 345,348d305 < MOVL $0x80, DX < MOVB $0x17, AL < OUTB < 361,363d317 < MOVL $0x80, DX < MOVB $0x18, AL < OUTB 371,374d324 < < MOVL $0x80, DX < MOVB $0x19, AL < OUTB p9%
/sys/src/boot/pc/ether.c -- modified to probe for ethernet cards rather than expect it to be configured from plan9.ini (there is no plan9.ini). all ether devices found are given irq 9 (the geode hardwires the INTP lines to 10, but for some reason 10 does not work)
p9% diff boot/pc/ether.c /sys/src/boot/pc/ether.c
41d40
<
62,63c61,62
< // if(isaconfig("ether", ctlrno, ctlr) == 0)
< // continue;
---
> if(isaconfig("ether", ctlrno, ctlr) == 0)
> continue;
66,67d64
< memset(ctlr, 0, sizeof(Ether));
< strcpy(ctlr->type, ethercards[n].type);
73,74c70
< i = (*ethercards[n].reset)(ctlr);
< if(i < 0) {
---
> if((*ethercards[n].reset)(ctlr)){
76,78d71
< continue;
< } else if(i) {
< splx(x);
86d78
< //ctlr->irq = 9;
p9%
/sys/src/boot/pc/load.c -- hardcoded to boot off 'ether0' as soon as it has finished finding and configuring the (missing) pci devices and hard drives. if the bootp off ether0 fails (e.g. a bad kernel is given) load.c prompts for another boot device. the 'i'm too big' check is commented out. console support is hardwired (no plan9.ini to turn it on). lots of debuging output to the post card. the console() initialization is moved way ahead of everything else -- I wanted to have as much debugging output as possible!
p9% diff boot/pc/load.c /sys/src/boot/pc/load.c
125d124
<
149,162d147
< static int
< myboot(char* file)
< {
< char *eth = "ether0";
< Type *tp;
< Medium *mp;
<
< for(tp = types; tp->type != Tnil; tp++)
< for(mp = tp->media; mp; mp = mp->next)
< if(strcmp(mp->name, eth) == 0)
< boot(mp, file);
<
< }
<
252,254d236
< delay(100000);
<
< outb(0x80, 0x20);
256d237
< outb(0x80, 0x21);
258,264d238
< outb(0x80, 0x22);
<
< outb(0x80, 0x27);
< consinit("0", "115200");
< outb(0x80, 0x28);
< kbdinit();
<
266d239
< outb(0x80, 0x23);
268d240
< outb(0x80, 0x24);
270d241
< outb(0x80, 0x25);
272d242
< outb(0x80, 0x26);
274,277c244
< outb(0x80, 0x27);
< // consinit("0", "115200");
< outb(0x80, 0x28);
< // kbdinit();
---
> kbdinit();
279,283c246,247
< print("hi!\n");
< pcihinv(nil);
< outb(0x80, 0x29);
< // if((ulong)&end > (KZERO|(640*1024)))
< // panic("i'm too big\n");
---
> if((ulong)&end > (KZERO|(640*1024)))
> panic("i'm too big\n");
285d248
< outb(0x80, 0x30);
287d249
< outb(0x80, 0x31);
297d258
< outb(0x80, 0x32);
299d259
< outb(0x80, 0x33);
301,304c261,262
< // if((p = getconf("console")) != nil)
< // consinit(p, getconf("baud"));
<
< outb(0x80, 0x34);
---
> if((p = getconf("console")) != nil)
> consinit(p, getconf("baud"));
306d263
< outb(0x80, 0x35);
308d264
< outb(0x80, 0x36);
318d273
< outb(0x80, 0x37);
322d276
< outb(0x80, 0x38);
337d290
< outb(0x80, 0x39);
365,368d317
< outb(0x80, 0x40);
< myboot(file); /* hardcoded ether0 boot */
< outb(0x80, 0x41);
<
443a393,395
> extern void diff(char*);
>
> ulong palloc;
447,448d398
<
< static ulong palloc;
464d413
<
p9%
Everything else you'll find in the directory pertains to my attempts to fix the missing interrupts problem with the 8259 emulator (trap.c). To start clean you may want to remove those files...
The configuration files are greatly simplified -- I wanted to have as little unnecessary drivers as possible. I got the kernel down to 365K, stripped and gzipped...
/sys/src/9/pc/main.c -- lots and lots of debugging information
in main(). i wanted to make sure that if I crash anywhere during execution I could simply se what the post card says and know which part of main() i was in... Also some pci debugging information was added (pcihinv() prints out the pci devices)
p9% diff linuxbios/pc/main.c /sys/src/9/pc/main.c 76d75 < outb(0x80, 0xA0); 78d76 < outb(0x80, 0xA0); 80d77 < outb(0x80, 0xA1); 82,83d78 < outb(0x80, 0xA2); < kbdinit(); 85d79 < outb(0x80, 0xA3); 88d81 < outb(0x80, 0xA4); 91c84 < outb(0x80, 0xA6); --- > kbdinit(); 93d85 < outb(0x80, 0xA7); 95d86 < outb(0x80, 0xA8); 97d87 < outb(0x80, 0xA9); 99d88 < outb(0x80, 0xAa); 101d89 < outb(0x80, 0xAb); 103d90 < outb(0x80, 0xAc); 105d91 < outb(0x80, 0xAd); 107d92 < outb(0x80, 0xAe); 109d93 < outb(0x80, 0xAf); 111d94 < outb(0x80, 0xb0); 113d95 < outb(0x80, 0xb1); 116d97 < outb(0x80, 0xb2); 118d98 < outb(0x80, 0xb3); 120d99 < outb(0x80, 0xb4
(Missing?)
