Installing Darwin with QEMU

1. Darwin 8.0.1 (corresponding to Mac OS X 10.4) seems to be the latest available full installer image, at least, until the PureDarwin project produces a new one.

   • List of available ISO images

2. More recent versions of packages are available in source form:

   • Open Source website (links by OS release)

   • Full list of packages (some aren't linked under any OS release)

Installing

1. Download and extract installation CD image:

   • Darwin 8.0.1 (was under “Darwin 8.0.1 Installer CD” on old website)

     • MD5: dbd260dda994093a11c31afbe624aa34

     • SHA-256: a26f9f14795fe0687bd647d41b712464c9a61430736fae4aa0fdb89207e1a62a

   • $ gunzip darwinx86-801.iso.gz

2. Set up QEMU VM:

   • $ qemu-img create -f qcow2 darwin.qcow2 10G

3. Start VM:

   • $ qemu -net none -drive file=darwin.qcow2,cache=writeback -cdrom darwinx86-801.iso -boot d

   • Other useful qemu options: -m 512 and -enable-kqemu

4. Installation steps:

   • First boot:

     • Select disk

     • "2" (manual partitioning)

     • "y" (initialize MBR)

     • In fdisk:

       • > auto hfs

       • Ignore the warning

       • > update

       • > write

       • > quit

     • Enter partition name

     • "yes" (clean install)

     • "darwin" (volume name)

     • Continue (reboot)

   • Second boot (make sure to boot from CD again):

     • Select disk

     • "3" (existing partition)

     • Enter partition name

     • "hfs" (HFS+ filesystem)

     • "yes" (clean install)

     • "darwin" (volume name)

     • Wait for installation to complete...

     • Enter root password

     • "darwin" (hostname)

     • "3" (spawn shell)

     • # halt

5. Configure VM for normal startup:

   • Remove QEMU flags -cdrom darwinx86-801.iso -boot d

Basic configuration

Enable VM networking

• Change QEMU flags: -net none → -net nic,model=rtl8139 -net user

SSH access

1. Change QEMU flags: -net user → -net user,hostfwd=tcp:127.0.0.1:10022-:22 (pick any port instead of 10022)

2. Log in to VM, enable SSH:

   • # service ssh start

3. Connect to VM with

   • $ ssh -p 10022 root@localhost

4. Optionally add an alias to host ~/.ssh/config to simplify connecting:

   • Host darwin-vm
     HostName localhost
     Port 10022
     User root

   • Connect to VM with

     • ssh darwin-vm

5. Install public key to simplify logging in:

   • $ cat .ssh/id_rsa.pub | ssh darwin-vm 'mkdir .ssh; cat >>.ssh/authorized_keys'

6. Add -nographic to QEMU flags to disable console window, which is no longer required

Some familiar aliases

• # echo "alias ll='ls -l'" >>/etc/bashrc

• # echo "alias la='ls -lA'" >>/etc/bashrc

Timezone

• # ln -sf /usr/share/zoneinfo/UTC /etc/localtime

Temporary filesystem

Using a temporary disk image to build software helps keep the main disk image file smaller.

1. $ qemu-img create -f qcow2 scratch.qcow2 10G

2. Add QEMU flag: -drive file=scratch.qcow2,cache=writeback and boot

3. Figure out which disk number corresponds to the scratch drive:

   • # mount

   • # ls /dev/rdisk*

   • It's the one that isn't mounted and doesn't have any partitions (sn-suffixed files)

   • It's usually, but not always, /dev/rdisk1

4. # newfs_hfs -v scratch /dev/rdisk1

5. # reboot

6. Available as /Volumes/scratch on next boot

Notes

1. The VM sometimes fails to boot with "panic(...): nfs_boot_init failed"; if this happens, restart it.

Updating the system

Kernel (xnu)

• It breaks support for FAT (and thus the QEMU virtual FAT drive)

  • Support for FAT is in the msdosfs package which requires Xcode to build

  • An alternative to the virtual FAT drive for transferring files is writing tar archives directly to an unpartitioned drive

  • SSH scp is another alternative

• Requires:

  • corresponding cctools (e.g. initially installed version or cctools-590.42.1, but not cctools-667.3)

  • gcc 3.3 (revert if changed with gcc_select 3.3)

• Source package: xnu-792.6.76.tar.gz (update to version listed under “Mac OS X 10.4.3”)

  • MD5: 854f44519778e8bde4283e275ed154e6

  • SHA-256: 35c5ed2f1399c770583a229a733d064dc302ae6327a7fcb40996e1f3c474f568

• Building:

  • # cd /Volumes/scratch

  • # tar xzf xnu-792.6.76.tar.gz

  • # cd xnu-792.6.76

  • Patch to help build gcc_42-5577:

    • # sed -i.tmp 's/defined *(__i386__)/& || defined(__x86_64__)/' bsd/{machine,sys}/*.h

  • # make DSTROOT= install

• Reboot. uname -r is now 8.7.0.

Standard library (Libc)

• Requires updated xnu (xnu-792.6.761).

• Source package: Libc-391.2.10.tar.gz (update to version listed under “Mac OS X 10.4.3”)

  • MD5: 7a1a08d1b68668fc41916d6cf39182a4

  • SHA-256: e90b78d310235544623f26c6f18e27b329b5bc778deab8e57332e8e90ab92f11

• Building:

  • # cd /Volumes/scratch

  • # tar xzf Libc-391.2.10.tar.gz

  • # cd Libc-391.2.10

  • # sed -i.tmp s/NOTIFY_STATUS_OK/0/g gen/{asl.c,syslog.c}

  • Patch to help build gcc_42-5577:

    • # sed -i.tmp 's/defined *(__i386__)/& || defined(__x86_64__)/' include/machine/*.h

  • # make OBJROOT="$PWD"/obj install

Upgrading GCC

dyld

• This is optional.

• Source package: dyld-46.16.tar.gz (under “Mac OS X 10.4.11.x86”)

  • MD5: a97d4d2a77b3e5f2ff9757007cae0596

  • SHA-256: cf753c3a2cef239b1334c56603b36d206f54d613daa078ce0f2d73c3e2a0dd82

• Makefile: dyld.mk

  • Darwin doesn't include Xcode, which is required to build this package. This makefile provides alternative build instructions.

• Building:

  • # cd /Volumes/scratch

  • # tar xzf dyld-46.16.tar.gz

  • # cd dyld-46.16

  • # sed -i.tmp '/case CPU_TYPE_X86_64:/,/break;/d;/__pthread_tsd_first/d' src/dyld.cpp

  • # ln -s libstdc++.a /usr/lib/gcc/i686-apple-darwin8/4.0.0/libstdc++-static.a

  • # bsdmake -f dyld.mk VERSION_DYLD=46 install

cctools

• Choice of version:

  • cctools-667.3

    • Too new to build xnu.

    • Source package: cctools-667.3.tar.gz (under “Mac OS X 10.5.8”)

      • MD5: 518166e6ddbd0287bebee3d00fddee7d

      • SHA-256: 1ba43a3d3bcf138a196e714666927c706857226adccf2e69db4f08e940631c0d

  • cctools-590.42.1

    • Too old to build gcc.

    • Source package: cctools-590.42.1.tar.gz (update to version listed under “Mac OS X 10.4.3”)

      • MD5: 6d875c5483699fd0f1e150facae35256

      • SHA-256: 61c86c4dc556daafbabebd8162bfbce8214843b218fefbd15c6c1ba03d225a10

• Building:

  • # cd /Volumes/scratch

  • # tar xzf cctools-667.3.tar.gz

  • # cd cctools-667.3

  • # sed -i.tmp '/install.*strip/{h;s/strip/seg_hack/gp;g;s/ -s / /;}' misc/Makefile

  • # sed -i.tmp s/ld_classic/ld/ ld/Makefile

  • # make install

• The new assembler will often show the warning "indirect jmp without '*'" on code generated by the old GCC.

gcc

• Choice of version:

  • gcc_42-5577

    • Latests gcc_42 package (newer packages are named gcc). GCC 4.2.1. Requires patched system include files, which can be done when upgrading xnu and Libc (see above).

    • Source package: gcc_42-5577.tar.gz (update to version listed under “Mac OS X 10.5.8”)

      • MD5: dab7ad45f76919f058a6f1cf3a0e91d8

      • SHA-256: fd6459ab701b41dc1297cdbc27f302c558d766505cfe8dd1d6ec0d257fef0e81

  • gcc_42-5531

    • Slightly older version. Doesn't require any changes to include files.

    • Source package: gcc_42-5531.tar.gz (under “Mac OS X 10.5.8”)

      • MD5: 959ecd224cea2477d57b1c3026fe05ee

      • SHA-256: 924862e2092fa11754ec9226a0de4772d831c40500231728055d00d1bb3a632e

• Requires cctools-667.3 and optionally dyld

  • Building:

    • # cd /Volumes/scratch

    • # tar xzf gcc_42-5577.tar.gz

    • # cd gcc_42-5577

    • If dyld isn't upgraded, patch to revert debugging format from DWARF to stabs:

      • # sed -i.tmp 's/\(#define PREFERRED_DEBUGGING_TYPE \).*/\1DBX_DEBUG/' gcc/config/darwin.h

      • # sed -i.tmp '/darwin_macho_att_stub/s/Init.*//' gcc/config/darwin.opt

    • # sed -i.tmp '/x86_64/s/|| exit 1//' build_gcc

    • # ln -s true /usr/bin/dsymutil

    • # gnumake RC_ARCHS=i386 install

      • Don't try to set DSTROOT=/, it deletes everything.

    • # cp -pR dst/* /

    • # cp -pR obj/dst-i686-i686/usr/lib/libgcc_s* /usr/lib/gcc/i686-apple-darwin8/4.2.1/

• GCC is now installed as gcc-4.2.

  • It can be made default with gcc_select 4.2.