ARM-Linux driver transplantation--RTC (real-time clock) transplantation

Hardware platform: FL2440

Kernel version: 2.6.28

Host platform: Ubuntu 11.04

Kernel version: 2.6.39

First modify the kernel source code /arch/arm/mach-s3c2410/mach-smdk2410.c

Add red font part

After the burning is completed, start the development board, and the startup information is as follows:

+------------------------------------------------------------+
| FL2440 Bootloader VER-5.1 Modified By Yan Ming! |
|------------------------------------------------------------|
|------------------------------------------------------------|
|CPU ID is 0x32440001 |
|FCLK=400MHz,HCLK=100MHz,PCLK=50MHz, CPU is running at 400MHz|
|UPLL=96MHz, UCLK=48MHz |
|Serial port 0, Baud rate is 115200. |
|OS image stored in NAND Flash. |
|Autoboot delay is 2 seconds. |
+------------------------------------------------------------+
Set boot params = root=/dev/mtdblock3 init=/linuxrc load_ramdisk=0 console=ttyS 
Load Kernel... 
Uncompressing Linux.............................................................
Linux version 2.6.28.7 (yan@yan-laptop) (gcc version 3.4.1) #343 Sun Jul 3 19:11
CPU: ARM920T [41129200] revision 0 (ARMv4T), cr=c0007177 
CPU: VIVT data cache, VIVT instruction cache 
Machine: SMDK2410 
ATAG_INITRD is deprecated; please update your bootloader. 
Memory policy: ECC disabled, Data cache writeback 
CPU S3C2440A (id 0x32440001) 
MM: CPU does not support supersection mapping for 0x55000000000 at 0xf0d00000 
S3C244X: core 400.000 MHz, memory 100.000 MHz, peripheral 50.000 MHz 
S3C24XX Clocks, (c) 2004 Simtec Electronics 
CLOCK: Slow mode (1.500 MHz), fast, MPLL on, UPLL on 
Built 1 zonelists in Zone order, mobility grouping on. Total pages: 16256 
Kernel command line: root=/dev/mtdblock3 init=/linuxrc load_ramdisk=0 console=t 
irq: clearing pending ext status 00080000 
irq: clearing subpending status 00000092 
PID hash table entries: 256 (order: 8, 1024 bytes) 
timer tcon=00500d00, tcnt a2c1, tcfg 0000020f,00000030, usec 00001eb8 
Console: colour dummy device 80x30 
console [ttySAC0] enabled 
Dentry cache hash table entries: 8192 (order: 3, 32768 bytes) 
Inode-cache hash table entries: 4096 (order: 2, 16384 bytes) 
Memory: 64MB = 64MB total 
Memory: 61120KB available (3288K code, 312K data, 144K init) 
Calibrating delay loop... 199.47 BogoMIPS (lpj=498688) 
Mount-cache hash table entries: 512 
CPU: Testing write buffer coherency: ok 
net_namespace: 288 bytes 
NET: Registered protocol family 16 
S3C2440: Initialising architecture 
S3C2440: IRQ Support 
S3C24XX DMA Driver, (c) 2003-2004,2006 Simtec Electronics 
DMA channel 0 at c4808000, irq 33 
DMA channel 1 at c4808040, irq 34 
DMA channel 2 at c4808080, irq 35 
DMA channel 3 at c48080c0, irq 36 
S3C244X: Clock Support, DVS off 
SCSI subsystem initialized 
usbcore: registered new interface driver usbfs 
usbcore: registered new interface driver hub 
usbcore: registered new device driver usb 
NET: Registered protocol family 2 
IP route cache hash table entries: 1024 (order: 0, 4096 bytes) 
TCP established hash table entries: 2048 (order: 2, 16384 bytes) 
TCP bind hash table entries: 2048 (order: 1, 8192 bytes) 
TCP: Hash tables configured (established 2048 bind 2048) 
TCP reno registered 
NET: Registered protocol family 1 
NetWinder Floating Point Emulator V0.97 (extended precision) 
Installing knfsd (copyright (C) 1996 okir@monad.swb.de). 
JFFS2 version 2.2. (NAND) (SUMMARY) 2001-2006 Red Hat, Inc. 
yaffs Jul 3 2011 19:14:41 Installing. 
msgmni has been set to 119 
io scheduler noop registered 
io scheduler anticipatory registered (default) 
io scheduler deadline registered 
io scheduler cfq registered 
Console: switching to colour frame buffer device 40x30 
fb0: s3c2410fb frame buffer device 
lp: driver loaded but no devices found 
ppdev: user-space parallel port driver 
Serial: 8250/16550 driver4 ports, IRQ sharing enabled 
s3c2440-uart.0: s3c2410_serial0 at MMIO 0x50000000 (irq = 70) is a S3C2440 
s3c2440-uart.1: s3c2410_serial1 at MMIO 0x50004000 (irq = 73) is a S3C2440 
s3c2440-uart.2: s3c2410_serial2 at MMIO 0x50008000 (irq = 76) is a S3C2440 
brd: module loaded 
loop: module loaded 
dm9000 Ethernet Driver, V1.31 
eth0: dm9000a at c487a300,c487e304 IRQ 51 MAC: 00:12:34:56:80:49 (chip) 
Uniform Multi-Platform E-IDE driver 
ide-gd driver 1.18 
ide-cd driver 5.00 
Driver 'sd' needs updating - please use bus_type methods 
S3C24XX NAND Driver, (c) 2004 Simtec Electronics 
s3c2440-nand s3c2440-nand: Tacls=3, 30ns Twrph0=7 70ns, Twrph1=3 30ns 
NAND device: Manufacturer ID: 0xad, Chip ID: 0xda (Hynix NAND 256MiB 3,3V 8-bit)
NAND_ECC_NONE selected by board driver. This is not recommended !! 
Scanning device for bad blocks 
Bad eraseblock 1771 at 0x0dd60000 
Creating 4 MTD partitions on "NAND 256MiB 3,3V 8-bit": 
0x00000000-0x00100000 : "Boot" 
0x00140000-0x00500000 : "MyApp" 
0x00500000-0x00800000 : "Kernel" 
0x00800000-0x0f800000 : "fs_yaffs" 
usbmon: debugfs is not available 
ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver 
s3c2410-ohci s3c2410-ohci: S3C24XX OHCI 
s3c2410-ohci s3c2410-ohci: new USB bus registered, assigned bus number 1 
s3c2410-ohci s3c2410-ohci: irq 42, io mem 0x49000000 
usb usb1: configuration #1 chosen from 1 choice 
hub 1-0:1.0: USB hub found 
hub 1-0:1.0: 2 ports detected 
usbcore: registered new interface driver libusual 
usbcore: registered new interface driver usbserial 
USB Serial support registered for generic 
usbcore: registered new interface driver usbserial_generic 
usbserial: USB Serial Driver core 
USB Serial support registered for FTDI USB Serial Device 
usbcore: registered new interface driver ftdi_sio 
ftdi_sio: v1.4.3:USB FTDI Serial Converters Driver 
USB Serial support registered for pl2303 
usbcore: registered new interface driver pl2303 
pl2303: Prolific PL2303 USB to serial adaptor driver 
mice: PS/2 mouse device common for all mice 
S3C24XX RTC, (c) 2004,2006 Simtec Electronics 
s3c2410-rtc s3c2410-rtc: rtc disabled, re-enabling 
s3c2410-rtc s3c2410-rtc: rtc core: registered s3c as rtc0 
s3c2440-sdi s3c2440-sdi: host detect has no irq available 
mapped channel 0 to 0 
s3c2440-sdi s3c2440-sdi: powered down. 
s3c2440-sdi s3c2440-sdi: initialisation done. 
s3c2440-sdi s3c2440-sdi: running at 0kHz (requested: 0kHz). 
s3c2440-sdi s3c2440-sdi: running at 196kHz (requested: 195kHz). 
s3c2440-sdi s3c2440-sdi: running at 196kHz (requested: 195kHz). 
s3c2440-sdi s3c2440-sdi: running at 196kHz (requested: 195kHz). 
s3c2440-sdi s3c2440-sdi: powered down. 
usbcore: registered new interface driver usbhid 
usbhid: v2.6:USB HID core driver 
mapped channel 10 to 2 
mapped channel 9 to 1 
UDA1341 audio driver initialized 
TCP cubic registered 
NET: Registered protocol family 17 
RPC: Registered udp transport module. 
RPC: Registered tcp transport module. 
s3c2410-rtc s3c2410-rtc: setting system clock to 2011-07-04 20:15:05 UTC (13098)
yaffs: dev is 32505859 name is "mtdblock3" 
yaffs: passed flags "" 
yaffs: Attempting MTD mount on 31.3, "mtdblock3" 
yaffs: auto selecting yaffs2 
yaffs: restored from checkpoint 
yaffs_read_super: isCheckpointed 1 
VFS: Mounted root (yaffs filesystem). 
Freeing init memory: 144K 
usb 1-1: new full speed USB device using s3c2410-ohci and address 2 
usb 1-1: configuration #1 chosen from 1 choice 
hub 1-1:1.0: USB hub found 
hub 1-1:1.0: 4 ports detected 
Mounting /proc,/sys,/dev...... 
Starting mdev...... 
init started: BusyBox v1.9.2 (2011-06-13 18:52:29 CST) 
starting pid 900, tty ': '/etc/init.d/rcS' 
dm9000 dm9000.0: WARNING: no IRQ resource flags set. 
eth0: link down 

Please press Enter to activate this console. eth0: link up, 100Mbps, full-duple1

The back color part shows that the RTC is working properly.

Use Commands

After the date command is used to modify the system time, execute hwclock -w to save the time to the hardware real-time clock.

Execute hkclock -s every time you start the computer. In this way, the system will read the time information from the hardware and save it to the system every time you start the computer.