|Index of /CE/AC/geezer/osd/code|
Name Last modified Size Description
Parent Directory 15-Jun-2004 22:54 - boot/ 07-Jan-2003 22:41 - dj.mak 07-Jan-2003 22:47 1k inc/ 07-Jan-2003 22:44 - krnl1m.ld 07-Jan-2003 22:47 1k lib/ 07-Jan-2003 22:50 - linux.mak 07-Jan-2003 22:47 1k ming.mak 07-Jan-2003 22:47 1k mnt/ 07-Jan-2003 22:44 - osd.tgz 15-Jan-2003 00:55 92k osd.zip 15-Jan-2003 00:55 125k osd3/ 07-Jan-2003 22:44 - osd4/ 07-Jan-2003 22:44 - osd5/ 07-Jan-2003 22:45 - osd6/ 07-Jan-2003 22:45 - osd7/ 07-Jan-2003 22:46 - osd8/ 07-Jan-2003 22:46 - osd9/ 07-Jan-2003 22:47 -
OSD demo code - Interim release (January, 2003) I am working a new set of kernels, but it's slow going, so here are the old kernels with some bug fixes and improvements. Location of these files: http://www.execpc.com/~geezer/osd/code The GRUB bootloader is GPL, all other files are PUBLIC DOMAIN (no copyright). You may do whatever you want with them. ================================================================ QUICK START ================================================================ 1. Make sure you have all the software tools you need. You need NASM: http://nasm.sourceforge.net You need the GNU C compiler (GCC), including binutils, GNU Make, and sed. Users of DOS and Win9x should get GCC for DOS (DJGPP): http://www.delorie.com/djgpp Find a mirror site near you and download the following packages (NNN is version number): compiler v2gnu/gccNNNNb.zip binutils v2gnu/bnuNNNNb.zip libraries v2/djdevNNN.zip Make v2gnu/makNNNNb.zip sed v2gnu/sedNNb.zip CWSDPMI v2misc/csdpmiN.zip Users of WinNT/Win2000/WinXP should get GCC for Win32 (MinGW): http://mingw.sourceforge.net Users of Linux can use the GNU tools that come with Linux. If they're not already installed, check the CD-ROMs or FTP site from where you got Linux. DOS and Windows users also need John Fine's Partial Copy (PARTCOPY): http://www.execpc.com/~geezer/johnfine/#zero 2. Create a formatted floppy disk with the GRUB bootloader installed on it. The procedure to do this is described below. 3. Got your tools? Got your GRUB floppy? Then you're ready to build and install the demo kernels. If you're using DJGPP, type make -f dj.mak install If you're using MinGW, type make -f ming.mak install If you're using Linux, type make -f linux.mak install Hopefully, everything will work properly. If it does, you'll be left with a bootable GRUB floppy with 7 demo kernels on it (OSD 3 - OSD 9). ================================================================ MAKING A BOOTABLE FLOPPY DISK WITH THE GRUB BOOTLOADER ON IT ================================================================ GRUB is a GPLed bootloader. Home page: http://www.gnu.org/software/grub Binaries: ftp://alpha.gnu.org/gnu/grub/grub-0.90-i386-pc.tar.gz Source code: ftp://alpha.gnu.org/gnu/grub/grub-0.90.tar.gz HOW-TOs: http://www.washingdishes.freeuk.com/grubtut.html http://www.execpc.com/~geezer/osd/boot/grub-how.txt 1. You will need - Two 1.44 meg floppy disks, one of them formatted with a filesystem that GRUB recognizes (e.g. FAT12 or ext2). The other floppy (the "unformatted" floppy) may contain a filesystem, but it will be destroyed. - The GRUB binaries: files "stage1" and "stage2". These are in the OSD distribution, in the directory "boot/grub". - A "menu.lst" configuration file for GRUB. Again, this is provided with OSD in the "boot/grub" directory. 2. On the formatted floppy disk, create the subdirectory "/boot/grub/", and copy the files "stage1", "stage2", and "menu.lst" into this subdirectory. 3. Concatenate the binary files "stage1" and "stage2" into a single binary file named "boot": (DOS/Windows): copy /b stage1 + stage2 boot (Linux): cat stage1 stage2 >boot 4. Write the file "boot" directly to the unformatted floppy. This is a sector-level write that does not use (and will destroy) any filesystem present on the disk: (DOS/Windows): partcopy boot 0 168000 -f0 (Linux): cat boot >/dev/fd0 PARTCOPY will display an error message because "boot" is much shorter than 0x168000 bytes, but this is OK. 5. Boot your PC from the unformatted floppy disk. 6. After GRUB has started, eject the unformatted floppy and insert the formatted floppy, containing the "stage1", "stage2", and "menu.lst" files, all in the "/boot/grub/" subdirectory. Type: setup (fd0) 7. The formatted floppy is now bootable. Do not move, modify, or delete the file "/boot/grub/stage2" on this floppy. ================================================================ BUGS/GOTCHAS/"IT DOESN'T WORK!" ================================================================ - DJGPP crashes under Windows XP The DJGPP team is working on a way to fix this. If you have any flavor of WindowsNT (including WindowsXP) use MinGW instead of DJGPP. - Will CygWin work instead of MinGW? Probably, but I haven't tested it. - 'make -f ming.mak clean' doesn't delete .o files in /lib/ I know, but I can't figure out how to fix it. Make sure these files get deleted if you switch between MinGW and DJGPP. The linkers can't distinguish between DJGPP COFF .o files and Win32 PE COFF .o files, but they ARE different, and your kernels will crash if you mix the two COFF types. - BFD: Dwarf Error: Abbrev offset (1075154) greater than or equal to .debug_abbrev size (3198). This is a bug in new versions of DJGPP. It's ugly, but you can ignore it. - Do not use MinGW GCC 2.x with NASM MinGW based on GCC 2.95.2 stores the BSS size in the wrong field of the section header. Because of this bug, this version of MinGW will not interoperate with other toolchains, including NASM, Microsoft compilers, and Borland compilers. - Screen fills with errors when compiling under Linux There are two possible causes for this: 1. Linux GCC chokes on DOS-style newlines in the source code. Get the .tgz file instead of the .zip file, or run all the source code files and makefiles through 'fromdos' to convert the DOS newlines (CR-LF) to UNIX newlines (LF only). 2. There is no newline at the very end of the file. - ld: krnl.x: Not enough room for program headers, try linking with -N This error occurs if you do not use AT() in the linker script when making an ELF kernel. - Exception 10 (bad TSS) If the NT bit in the EFLAGS register is set, IRET will attempt a TSS-based task-switch, instead of a normal IRET. Code was added to osd9/kstart.asm to prevent this. (GRUB 0.90 leaves the NT bit set when it jumps to the kernel.) - Errors from GRUB: 'Error: Loading below 1M not supported' 'Error 28: Selected item won't fit into memory' These errors are usually caused by improperly-linked ELF kernels. If your kernel is ELF, try this: objdump --private-headers -h krnl.x The vaddr and paddr fields for each program header (segment) must be at or above 1 meg (00100000h) but smaller than your RAM size. If you have readelf, you can also do this: readelf --segments krnl.x If you find a segment with bad values of VirtAddr or PhysAddr, look at the section-to-segment mapping to see which section is causing the problem. ================================================================ DEMO CODE OVERVIEW ================================================================ osd3 mixing C and asm, C calling convention, underscores (xxx - current code does not demonstrate these very well) osd4 putch() and kprintf() osd5 C library code moved to separate directory osd6 software interrupts, exception handlers in asm and C osd7 hardware interrupts, reprogramming the 8259 interrupt controller chips, simple keyboard driver osd8 multitasking preliminaries: multiple (virtual) consoles backed with video memory, ANSI/VT escapes for moving the cursor and changing text color. Improved keyboard driver; can press Ctrl+Alt+Del to reboot. osd9 cooperative multitasking with setjmp() and longjump() (static tasks; linked into the kernel at compile-time) ================================================================ WHAT CHANGED? ================================================================ - Updated GRUB to version 0.90 - Wrote MinGW makefiles, and fixed code to work with MinGW based on GCC 3.x (and generate error message for GCC 2.x) - Fixed definition of MAKEFILE in lib/linux.mak - BIG changes to linker script - Unified ELF/DJGPP COFF/Win32 PE COFF linker scripts into one - Added AT() statements so ELF kernels link properly, and work properly - Now handling .rodata section properly, so ELF kernels work properly (including multiple .rodata sections with GCC 3.x) - Rewrote setjmp() and longjmp() because they were buggy (though, strangely enough, the bug did not manifest itself) - Added code to osd9/kstart.asm to zero NT bit in EFLAGS, preventing exception 10 - Now enabling interrupts for each task in function init_tasks() of osd9/sched.c. In previous code, interrupts were disabled for all tasks except the idle task, making the blinking character in the upper left corner of the screen appear to blink much more slowly than 18 Hz.