"RHEL 8 and 9 fails to boot after adding `memmap` paramter to grub"

Issue

• Updating the kernel with the memmap parameter using grubby fails on RHEL 8 and RHEL 9.
• Adding a memmap parameter (e.g., memmap=1G\$4G nspcie.memmap=1G@4G) causes the system to hang during boot. However, removing the parameter allows the system to boot successfully.

• System panics on boot with Kernel panic - mot syncing: UFS: Unable to mount root fs on unknown-block(0,0)

   1.249274] Kernel panic - mot syncing: UFS: Unable to mount root fs on unknown-block(0,0)
   [ 1.2562931 CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.18.0-553.e18_10.x86_6
   4 #1
   [ 1.251161] Hardware name: QEMU Standard PC (G35 + ICH9, 2009), BIOS 1.16.3-1
   .fc39 04/01/2014
   [     1.2524821 Call Trace:
   [     1.2529631  dump_stack+Ox41/0x60
   [     1.2534561  panic+0xe?/0x2ac
   [     1.2538911 mount block _root+0x2Zbe/@xZe6
   [     1.2544131 7 do_early_params+0x95/0x95
   [     1.2548961 prepare_namespace +0x135/0x16b
   [     1.2553941 kernel _init_freeable+0x208/0x232tive.
   [     1.2559161 7 rest_init+@xaa/Oxaa
   [     1.2563331 kernel _init+Oxa/0x104
   [     1.2567391 ret _from_fork+0x1f/0x40
   [     1.2572671 Kernel Offset: Ox1cO0000 from OxFfffffffB1000000 (relocation rang
   [ OXPPEEfL11BOOO000O-OXTE EF EFLEDELLELEE)
   [     1.2583691 ——- end Kernel panic - not syncing: UFS: Unable to mount root fs on unknown-block(0,0) ]