can't run '/etc/init.d/rcS': No such file or directory - qemu

Question

I am trying to emulate a firmware image using qemu. During booting, I get the following error
can't run '/etc/init.d/rcS': No such file or directory
can't open /dev/ttyS0: No such file or directory
can't open /dev/ttyS0: No such file or directory
can't open /dev/ttyS0: No such file or directory
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.
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This is the content of the inittab file
# Startup the system
null::sysinit:/etc/init.d/rc.sysinit
# now run any rc scripts
::sysinit:/etc/init.d/rcS
# Put a getty on the serial port
ttyS0::respawn:/sbin/getty -L ttyS0 115200 vt100
# Stuff to do before rebooting
null::shutdown:/bin/umount -a -r
It is able to run the rc.sysinit, but not the rcS.
I have checked permissions of the rcS. Also, the filesystem is mounted as read-only cramfs. Could this be causing an issue?
This is the command I am running:
QEMU_AUDIO_DRV=none \qemu-system-arm -m 256M -M versatilepb
-kernel ~/linux-2.6.23/arch/arm/boot/zImage
-append "console=ttyAMA0,115200 root=/dev/ram rdinit=/sbin/init"
-initrd ~/tmpcramfs2
-nographic
These are the boot messages obtained on running the command:
Linux version 2.6.23 (hsailer#SvanteArrhenius) (gcc version 4.0.2) #1 Thu May 27 09:31:10 EDT 2021
CPU: ARM926EJ-S [41069265] revision 5 (ARMv5TEJ), cr=00093177
Machine: ARM-Versatile PB
Memory policy: ECC disabled, Data cache writeback
CPU0: D VIVT write-through cache
CPU0: I cache: 4096 bytes, associativity 4, 32 byte lines, 32 sets
CPU0: D cache: 65536 bytes, associativity 4, 32 byte lines, 512 sets
Built 1 zonelists in Zone order. Total pages: 65024
Kernel command line: console=ttyAMA0,115200 root=/dev/ram rdinit=/sbin/init
PID hash table entries: 1024 (order: 10, 4096 bytes)
Console: colour dummy device 80x30
Dentry cache hash table entries: 32768 (order: 5, 131072 bytes)
Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
Memory: 256MB = 256MB total
Memory: 249600KB available (2508K code, 227K data, 100K init)
Mount-cache hash table entries: 512
CPU: Testing write buffer coherency: ok
NET: Registered protocol family 16
NET: Registered protocol family 2
Time: timer3 clocksource has been installed.
IP route cache hash table entries: 2048 (order: 1, 8192 bytes)
TCP established hash table entries: 8192 (order: 4, 65536 bytes)
TCP bind hash table entries: 8192 (order: 3, 32768 bytes)
TCP: Hash tables configured (established 8192 bind 8192)
TCP reno registered
checking if image is initramfs...it isn't (bad gzip magic numbers); looks like an initrd
Freeing initrd memory: 7184K
NetWinder Floating Point Emulator V0.97 (double precision)
Installing knfsd (copyright (C) 1996 okir#monad.swb.de).
JFFS2 version 2.2. (NAND) © 2001-2006 Red Hat, Inc.
JFS: nTxBlock = 2007, nTxLock = 16063
io scheduler noop registered
io scheduler anticipatory registered (default)
io scheduler deadline registered
io scheduler cfq registered
CLCD: Versatile hardware, VGA display
Clock CLCDCLK: setting VCO reg params: S=1 R=99 V=98
Console: switching to colour frame buffer device 80x60
Serial: AMBA PL011 UART driver
dev:f1: ttyAMA0 at MMIO 0x101f1000 (irq = 12) is a AMBA/PL011
console [ttyAMA0] enabled
dev:f2: ttyAMA1 at MMIO 0x101f2000 (irq = 13) is a AMBA/PL011
dev:f3: ttyAMA2 at MMIO 0x101f3000 (irq = 14) is a AMBA/PL011
fpga:09: ttyAMA3 at MMIO 0x10009000 (irq = 38) is a AMBA/PL011
RAMDISK driver initialized: 16 RAM disks of 8192K size 1024 blocksize
smc91x.c: v1.1, sep 22 2004 by Nicolas Pitre <nico#cam.org>
eth0: SMC91C11xFD (rev 1) at d098e000 IRQ 25 [nowait]
eth0: Ethernet addr: 52:54:00:12:34:56
armflash.0: Found 1 x32 devices at 0x0 in 32-bit bank
Intel/Sharp Extended Query Table at 0x0031
Using buffer write method
RedBoot partition parsing not available
afs partition parsing not available
armflash: probe of armflash.0 failed with error -22
mice: PS/2 mouse device common for all mice
input: AT Raw Set 2 keyboard as /class/input/input0
TCP cubic registered
NET: Registered protocol family 1
NET: Registered protocol family 17
VFP support v0.3: implementor 41 architecture 1 part 10 variant 9 rev 0
input: ImExPS/2 Generic Explorer Mouse as /class/input/input1
RAMDISK: cramfs filesystem found at block 0
RAMDISK: Loading 7184KiB [1 disk] into ram disk... done.
VFS: Mounted root (cramfs filesystem) readonly.
Freeing init memory: 100K
can't run '/etc/init.d/rcS': No such file or directory
can't open /dev/ttyS0: No such file or directory
can't open /dev/ttyS0: No such file or directory
can't open /dev/ttyS0: No such file or directory
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Answer 1

The errors about /dev/ttyS0 are because your inittab is specifying the wrong device name for the serial port for the (emulated) hardware you're running on. Your QEMU command specifies the 'versatilepb' board, whose serial devices are PL011s, which appear in /dev/ as /dev/ttyAMA0, /dev/ttyAMA1, etc. (/dev/ttyS0 is what the serial ports on an x86 PC appear as.) You need to fix that line of the inittab to refer to ttyAMA0 instead.
For the rcS error, I would suggest you start by double-checking all the things listed in all the responses to this older question.