Booting CentOS6.5 kernel failed with UEFI mode

[NiKiZe]

(2015-05-14 07:59)Hudson Wrote:  #!ipxe
kernel tftp://xxx.xxx.xxx.xxx/boot/vmlinuz initrd=initrd.img
initrd tftp://xxx.xxx.xxx.xxx/boot/initrd.img
boot

Looks good, the initrd= is needed under efi for the kernel to know which file on the efi fs that should be used.

(2015-05-14 07:59)Hudson Wrote:  But we tried to use it with the CentOS6.5 or the Ubuntu 1004, which kernel version is about 2.6.XX

We met the following errors with the kernel.
"Could not select: Exec format error (http://ipxe.org/2e008081)
Could not boot image: Exec format error (http://ipxe.org/2e008081)"

Is there any solution for supporting boot the old 2.6 kernel with iPXE in the UEFI mode?

iPXE only supports booting efi binaries and not linux kernels.
That means that the kernel needs to have efi stub enabled to be able too boot from ipxe, also 32 bit and 64 bit needs to match between firmware -> ipxe -> kernel and finaly secure boot needs to be disabled. (depending on the BIOS/Firmware implementation I have seen ipxe boot with secure boot enabled but it was unable to boot kernel)