VMWare ESXi boot over LAN (multiboot)

[Petr Moravek]

Hello Grub-ers!

I am trying to boot a ESXi installation with grub multiboot. The VMware is
using syslinux for that but as the multiboot should be present also in grub
I tried to adapt from syslinux to grub syntax, but so far without luck:

*Syslinux config:*

bootstate=0
kernel=tboot.b00
title=Loading VMware ESXi
prefix=http://192.168.32.1/
kernelopt=
modules=b.b00 --- jumpstrt.gz --- useropts.gz --- features.gz --- k.b00 ---
chardevs.b00 --- a.b00 --- user.b00 --- uc_intel.b00 --- uc_amd.b00 ---
sb.v00 --- s.v00 --- ata_liba.v00 --- ata_pata.v00 --- ata_pata.v01 ---
ata_pata.v02 --- ata_pata.v03 --- ata_pata.v04 --- ata_pata.v05 ---
ata_pata.v06 --- ata_pata.v07 --- block_cc.v00 --- char_ran.v00 ---
ehci_ehc.v00 --- elxnet.v00 --- hid_hid.v00 --- i40en.v00 --- igbn.v00 ---
ima_qla4.v00 --- ipmi_ipm.v00 --- ipmi_ipm.v01 --- ipmi_ipm.v02 ---
ixgben.v00 --- lpfc.v00 --- lsi_mr3.v00 --- lsi_msgp.v00 --- lsi_msgp.v01
--- misc_cni.v00 --- misc_dri.v00 --- mtip32xx.v00 --- ne1000.v00 ---
nenic.v00 --- net_bnx2.v00 --- net_bnx2.v01 --- net_cdc_.v00 ---
net_cnic.v00 --- net_e100.v00 --- net_e100.v01 --- net_enic.v00 ---
net_fcoe.v00 --- net_forc.v00 --- net_igb.v00 --- net_ixgb.v00 ---
net_libf.v00 --- net_mlx4.v00 --- net_mlx4.v01 --- net_nx_n.v00 ---
net_tg3.v00 --- net_usbn.v00 --- net_vmxn.v00 --- nhpsa.v00 ---
nmlx4_co.v00 --- nmlx4_en.v00 --- nmlx4_rd.v00 --- nmlx5_co.v00 ---
ntg3.v00 --- nvme.v00 --- nvmxnet3.v00 --- ohci_usb.v00 --- pvscsi.v00 ---
qedentv.v00 --- qfle3.v00 --- qflge.v00 --- qlnative.v00 --- sata_ahc.v00
--- sata_ata.v00 --- sata_sat.v00 --- sata_sat.v01 --- sata_sat.v02 ---
sata_sat.v03 --- sata_sat.v04 --- scsi_aac.v00 --- scsi_adp.v00 ---
scsi_aic.v00 --- scsi_bnx.v00 --- scsi_bnx.v01 --- scsi_fni.v00 ---
scsi_hps.v00 --- scsi_ips.v00 --- scsi_isc.v00 --- scsi_lib.v00 ---
scsi_meg.v00 --- scsi_meg.v01 --- scsi_meg.v02 --- scsi_mpt.v00 ---
scsi_mpt.v01 --- scsi_mpt.v02 --- scsi_qla.v00 --- shim_isc.v00 ---
shim_isc.v01 --- shim_lib.v00 --- shim_lib.v01 --- shim_lib.v02 ---
shim_lib.v03 --- shim_lib.v04 --- shim_lib.v05 --- shim_vmk.v00 ---
shim_vmk.v01 --- shim_vmk.v02 --- uhci_usb.v00 --- usb_stor.v00 ---
usbcore_.v00 --- vmkata.v00 --- vmkplexe.v00 --- vmkusb.v00 ---
vmw_ahci.v00 --- xhci_xhc.v00 --- emulex_e.v00 --- weaselin.t00 ---
esx_dvfi.v00 --- esx_ui.v00 --- lsu_hp_h.v00 --- lsu_lsi_.v00 ---
lsu_lsi_.v01 --- lsu_lsi_.v02 --- lsu_lsi_.v03 --- native_m.v00 ---
rste.v00 --- vmware_e.v00 --- vsan.v00 --- vsanheal.v00 --- vsanmgmt.v00
--- xorg.v00 --- imgdb.tgz --- onetime.tgz
build=6.5.0-4887370
updated=1

And my attempt in grub.cfg:
...
multiboot --quirk-modules-after-kernel /esx/tboot.b00
module /esx/b.b00
module /esx/jumpstrt.gz
module /esx/useropts.gz
module /esx/features.gz
echo "Booting..."
boot
...

the files are downloaded via http, I could even see the downloads in apache
access.log
the message "Booting..." appears but that is last thing that happened...

Some hints from:
https://docs.vmware.com/en/VMware-vSphere/6.7/com.vmware.esxi.upgrade.doc/GUID-147D7509-EFB1-4391-973F-48B015B85C83.html

Even the manual actually mentioned vmware:

-quirk-modules-after-kernel is needed for kernels which load at relatively
high address e.g. 16MiB mark and can’t cope with modules stuffed between
1MiB mark and beginning of the kernel.
Known afftected systems: VMWare.

Any idea what I did wrong where to look at?

Many thanx and have a nice day,

Petr