Hi all,
I just bought a PCIEx card with two serial ports (needed for my PABX software) on a host with ESX4 on it. I need now to install its drivers for it to be recognized by ESX and then I will be able o map those ports to a VM. I therefore copied the tar file in the tmp folder, uncompressed it, and when I do a make, as stated by the manufactures user guide for installing the driver in Linux, I have the following problem. Please note that I am completely new to Linux and don't know how to debug / troubleshoot anything !!! 
make[1]: Entering directory `/tmp/perle-serial-3.5.0/pparport26'
make -C /lib/modules/2.6.18-128.ESX/build SUBDIRS=/tmp/perle-serial-3.5.0/pparport26 modules
make: Entering an unknown directory
make: *** /lib/modules/2.6.18-128.ESX/build: No such file or directory. Stop.
make: Leaving an unknown directory
make[1]: Leaving directory `/tmp/perle-serial-3.5.0/pparport26'
Installing parallel driver...
make[1]: Entering directory `/tmp/perle-serial-3.5.0/pparport26'
install: cannot stat `pparport-pc.ko': No such file or directory
make[1]: Leaving directory `/tmp/perle-serial-3.5.0/pparport26'
./tar_install.sh: line 16: /etc/init.d/rc.pparport-pc: No such file or directory
make[1]: Entering directory `/tmp/perle-serial-3.5.0/pserial'
cc -I/usr/include -Wall -O2 -g swirl.c -o swirl \
make[1]: cc: Command not found
make[1]: Leaving directory `/tmp/perle-serial-3.5.0/pserial'
Installing serial driver...
make[1]: Entering directory `/tmp/perle-serial-3.5.0/pserial'
install: cannot stat `perle-serial.ko': No such file or directory
make[1]: Leaving directory `/tmp/perle-serial-3.5.0/pserial'
Starting to update modprobe.conf ... not required.
./tar_install.sh: line 108: /etc/init.d/rc.perle-serial: No such file or directory