Trouble booting Arch from VirtualBox vm with Mac OS X host

Question

Thank you in advance for your help.
I am trying to get Arch installed and running on a VirtualBox virtual machine within a Mac OS X host on my MacBook Air. For the last two days, I have tried many attempts (following various blogs for hints as to what subtle detail I must be missing), and they all have resulted in more or less the same result -- the bootloader never gets loaded. (See below for a description of what I see.) I tried one more time and recorded exactly what I have done so as to ask for help.
# selected "Boot Arch Linux (x86_64)" on boot from cd
$ pacman -Sy
$ gdisk /dev/sda # o n [enter] [enter] +1024M ef02 n [enter] [enter] [enter] [enter] w
$ mkfs.ext4 /dev/sda1
$ mkfs.ext4 /dev/sda2
$ mount /dev/sda2 /mnt
$ mkdir /mnt/boot
$ mount /dev/sda1 /mnt/boot
$ pacstrap -i /mnt base # [enter] for default selection
$ genfstab -p /mnt > /mnt/etc/fstab
$ arch-chroot /mnt
$ pacman -Sy
$ echo first-arch > /etc/hostname # I'm skipping all the other config options, which I don't expect to be relevant at this time.
$ passwd # sorry, not telling
$ pacman -S grub-bios
$ grub-install --target=i386-pc --recheck --debug /dev/sda # I read in another blog that i386-pc is the correct option even though my OS is targed to x86_64
$ grub-mkconfig -o /boot/grub/grub.cfg
$ exit
$ reboot
# I return to the menu (rebooting with cd still in) and select the "Boot existing OS" option. The result is an almost-blank screen with the text "Booting...\nGRUB ". Nothing else happens.
# I close the VM by clicking the 'x' on the window and choose the option to turn off. I start the VM again and remove the cd. Then I select the 'Reboot' option.
#     The result is an almost-blank screen with the text "EDD: Error 0c00 reading sector 41571\nFailed to load COM32 module boot/syslinux/reboot.c32\nboot:"
I was once confused why 'syslinux' appears on the error screen when I'm installing GRUB, but this is also essentially the error that shows if I try to run the machine before setting anything up, so it must be some sort of default.
I have also tried preparing my system as if it used UEFI (although I understand VirtualBox doesn't use UEFI).
I have also tried installing syslinux instead of GRUB, and was able to boot from the CD by selecting the option "Boot existing OS", but the regular boot without cd still failed. Although that is a workaround, I am wondering if there is a way I can boot without the CD every time. (Not just for convenience, but because I'm sure I'm missing some detail and I would like to learn what that is.)
Again, thank you in advance for your help.

Answer 1

A few days ago, i have installed it myself on a Mac. Everything works fine and i just followed the installation guide like you (but i used syslinux...).
But i am curious about your partition-mounting.
I think, grub looks on /dev/sda1 to boot up. But you installed arch to /dev/sda2.
I would try to use "pacstrap  -i /mnt/boot base" to install arch on /dev/sda1 ...
(If that does not work, you could try installing it without a special boot partition)