Using the Xilinx 16550 UART

Uart166550 clock frequency is taken from software setting Software->Software platform setting -> Drivers -> Driver Parameters: (CLOCK_HZ parameters). All CLOCK_HZ parameter value should be the same. FS-Boot and U-Boot uses console which is specified in stdin(stdout) properties in MSS file.

All PetaLogix software is setup for usage on 115200 baud rate. This option is due to faster loading SREC files via FS-Boot.

Here is the corresponding part for enabling uart16550 (and disabling uartlite) serial console in linux kernel.

#
# Serial drivers
#
CONFIG_SERIAL_8250=y
CONFIG_SERIAL_8250_CONSOLE=y
CONFIG_SERIAL_8250_NR_UARTS=4
CONFIG_SERIAL_8250_RUNTIME_UARTS=4
# CONFIG_SERIAL_8250_EXTENDED is not set

#
# Non-8250 serial port support
#
# CONFIG_SERIAL_UARTLITE is not set
CONFIG_SERIAL_CORE=y
CONFIG_SERIAL_CORE_CONSOLE=y
CONFIG_UNIX98_PTYS=y
CONFIG_LEGACY_PTYS=y
CONFIG_LEGACY_PTY_COUNT=256

Linux kernel log

Linux version 2.6.20-uc0 (monstr@petalogix.com) (gcc version 3.4.1 (
PetaLinux 0.20 Build -rc1 050607 )) #10 Thu Nov 20 11:43:14 CET 2008
setup_cpuinfo: initialising
setup_cpuinfo: No PVR support in CPU.  Using static compile-time info
set_cpuinfo_static: Using static CPU info.
setup_memory: max_mapnr: 0x8dfff
setup_memory: min_low_pfn: 0x8c000
setup_memory: max_low_pfn: 0x2000
On node 0 totalpages: 8192
 DMA zone: 64 pages used for memmap
 DMA zone: 0 pages reserved
 DMA zone: 8128 pages, LIFO batch:0
 Normal zone: 0 pages used for memmap
Built 1 zonelists.  Total pages: 8128
Kernel command line: console=ttyS0,115200
OPB INTC #0 at 0x81800000
PID hash table entries: 128 (order: 7, 512 bytes)
TIMER at 0x83C00000
Dentry cache hash table entries: 4096 (order: 2, 16384 bytes)
Inode-cache hash table entries: 2048 (order: 1, 8192 bytes)
Memory: 29960k/32768k available
Calibrating delay loop... 49.45 BogoMIPS (lpj=247296)
Mount-cache hash table entries: 512
NET: Registered protocol family 16
NET: Registered protocol family 2
IP route cache hash table entries: 1024 (order: 0, 4096 bytes)
TCP established hash table entries: 1024 (order: 0, 4096 bytes)
TCP bind hash table entries: 1024 (order: 0, 4096 bytes)
TCP: Hash tables configured (established 1024 bind 1024)
TCP reno registered
io scheduler noop registered
io scheduler anticipatory registered
io scheduler deadline registered
io scheduler cfq registered (default)
Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing disabled
serial8250.0: ttyS0 at MMIO 0x83e01003 (irq = 3) is a 16550A
RAMDISK driver initialized: 16 RAM disks of 8192K size 1024 blocksize
eth0: using fifo mode.
eth0: No PHY detected.  Assuming a PHY at address 0.
eth0: Xilinx EMACLite #0 at 0x81000000 mapped to 0x81000000, irq=1
uclinux[mtd]: RAM probe address=0x8c17f01c size=0xf6000
Creating 1 MTD partitions on "RAM":
0x00000000-0x000f6000 : "ROMfs"
uclinux[mtd]: set ROMfs to be root filesystem index=0
TCP cubic registered
NET: Registered protocol family 1
VFS: Mounted root (cramfs filesystem) readonly.
Freeing unused kernel memory: 84k freed
Mounting proc:
Mounting var:
Populating /var:
Running local start scripts.
Mounting /etc/config:
Populating /etc/config:
flatfsd: Nonexistent or bad flatfs (-48), creating new one...
flatfsd: Failed to write flatfs (-48): No such device
flatfsd: Created 5 configuration files (185 bytes)
Mounting sysfs:
Setting hostname:
Setting up interface lo:
Setting up interface eth0:
Starting thttpd:

uclinux login:

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