shellbt

기존에 bootargs에서는 root 파일시스템을 mtdblock[숫자]형태로 지정을 하게 했는데(jffs2)

arm용 2.6.27.8에서는 1f00, 1f01, 1f02, 1f03 형식으로 UUID랑 비슷하게 ID을 사용하게 바꿨다.

기존에 mtdblock3을 root 파일 시스템으로 사용했다면, 새로 바뀐것은 1f03을 root 파일 시스템 파티션으로 붙여 줘야 한다.

Uncompressing Linux............................................................................................... done, booting the kernel.
�Linux version 2.6.27.8 (shellbt@ubuntu) (gcc version 4.3.2 (crosstool-NG-1.3.1) ) #1 PREEMPT Wed Mar 28 13:46:30 KST 2012
CPU: ARM926EJ-S [41069264] revision 4 (ARMv5TEJ), cr=00053177
Machine: Phytec 3250 board with the LPC3250 Microcontroller
Memory policy: ECC disabled, Data cache writeback
CPU0: D VIVT write-back cache
CPU0: I cache: 32768 bytes, associativity 4, 32 byte lines, 256 sets
CPU0: D cache: 32768 bytes, associativity 4, 32 byte lines, 256 sets
Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 16256
Kernel command line: console=ttyS0,115200n81 root=/dev/mtdblock3 rw rootfstype=jffs2 ip=192.192.192.205 init=/sbin/init
PID hash table entries: 256 (order: 8, 1024 bytes)
Console: colour dummy device 80x30
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: 60676KB available (3700K code, 238K data, 232K init)
Calibrating delay loop... 103.68 BogoMIPS (lpj=207360)
Mount-cache hash table entries: 512
CPU: Testing write buffer coherency: ok
net_namespace: 288 bytes
NET: Registered protocol family 16
Invalid board descriptor!
LPC32XX DMA driver
LPC32XX unique ID: 0005b6dd75701b6e591c8cb710af2800
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 (double precision)
JFFS2 version 2.2. (NAND) �© 2001-2006 Red Hat, Inc.
yaffs Mar 28 2012 13:43:11 Installing.
msgmni has been set to 118
io scheduler noop registered
io scheduler anticipatory registered
io scheduler deadline registered
io scheduler cfq registered (default)
Serial: 8250/16550 driver4 ports, IRQ sharing disabled
serial8250.0: ttyS0 at MMIO 0x40090000 (irq = 9) is a 16550A
console [ttyS0] enabled
serial8250.0: ttyS1 at MMIO 0x40080000 (irq = 7) is a 16550A
serial8250.0: ttyS2 at MMIO 0x40088000 (irq = 8) is a 16550A
serial8250.0: ttyS3 at MMIO 0x40098000 (irq = 10) is a 16550A
lpc32xx_hsuart.0: ttyTX0 at MMIO 0x40014000 (irq = 26) is a lpc32xx_hsuart
lpc32xx_hsuart.0: ttyTX1 at MMIO 0x40018000 (irq = 25) is a lpc32xx_hsuart
lpc32xx_hsuart.0: ttyTX2 at MMIO 0x4001c000 (irq = 24) is a lpc32xx_hsuart
loop: module loaded
nbd: registered device at major 43
usbcore: registered new interface driver ub
LPC32XX_mii_bus: probed
eth0: LPC32XX mac at 0x31060000 irq 29
eth0: attached PHY driver [SMSC LAN8700] (mii_bus:phy_addr=0:1f, irq=-1)
Driver 'sd' needs updating - please use bus_type methods
NAND device: Manufacturer ID: 0xec, Chip ID: 0xf1 (Samsung NAND 128MiB 3,3V 8-bit)
Scanning device for bad blocks
Bad eraseblock 0 at 0x00000000
Bad eraseblock 1 at 0x00020000
Creating 4 MTD partitions on "lpc32xx_nand":
0x00000000-0x00180000 : "phy3250-boot"
0x00180000-0x001c0000 : "phy3250-ubt-prms"
0x001c0000-0x005c0000 : "phy3250-kernel"
0x005c0000-0x08000000 : "phy3250-rootfs"
Enable SPI clock
ttySCMA0 at I/O 0x1 (irq = 79) is a sc16is752
ttySCMA1 at I/O 0x2 (irq = 79) is a sc16is752
usbmon: debugfs is not available
I2C device at address 0x2d<6>ISP1301 Vendor ID  : 0x04cc
ISP1301 Product ID : 0x1301
ISP1301 Version ID : 0x0210
usb-ohci usb-ohci: at 0xf3120000, irq 0
usb-ohci usb-ohci: pnx4008 OHCI
usb-ohci usb-ohci: new USB bus registered, assigned bus number 1
usb-ohci usb-ohci: irq 59, io mem 0xf3120000
usb usb1: configuration #1 chosen from 1 choice
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 2 ports detected
Initializing USB Mass Storage driver...
usbcore: registered new interface driver usb-storage
USB Mass Storage support registered.
usbcore: registered new interface driver libusual
input: devkit3250-buttons as /class/input/input0
Initial gpio driver
rtc-lpc32xx rtc-lpc32xx: rtc core: registered rtc-lpc32xx as rtc0
i2c /dev entries driver
PNX4008-WDT: PNX4008 Watchdog Timer: heartbeat 19 sec
mmci-pl18x: DMA buffer(10000 bytes), P:0x839a0000, V:0xffc1c000
mmc0: MMCI rev 0 cfg 00 at 0x0000000020098000 irq 15,13
usbcore: registered new interface driver usbhid
usbhid: v2.6:USB HID core driver
Advanced Linux Sound Architecture Driver Version 1.0.17.
ASoC version 0.13.2
UDA1380 Audio Codec 0.6<6>asoc: UDA1380 <-> lpc3xxx-i2s1 mapping ok
ALSA device list:
  #0: LPC32XX (UDA1380)
TCP cubic registered
NET: Registered protocol family 17
RPC: Registered udp transport module.
RPC: Registered tcp transport module.
ieee80211: 802.11 data/management/control stack, git-1.1.13
ieee80211: Copyright (C) 2004-2005 Intel Corporation <jketreno@linux.intel.com>
VFP support v0.3: implementor 41 architecture 1 part 10 variant 9 rev 1
rtc-lpc32xx rtc-lpc32xx: setting system clock to 2016-06-20 20:47:54 UTC (1466455674)
IP-Config: Guessing netmask 255.255.255.0
IP-Config: Complete:
     device=eth0, addr=192.192.192.205, mask=255.255.255.0, gw=255.255.255.255,
     host=192.192.192.205, domain=, nis-domain=(none),
     bootserver=255.255.255.255, rootserver=255.255.255.255, rootpath=
VFS: Mounted root (jffs2 filesystem).
Freeing init memory: 232K
Warning: unable to open an initial console.
Failed to execute /sbin/init.  Attempting defaults...
Kernel panic - not syncing: No init found.  Try passing init= option to kernel.

LPC3250 devkit의 커널 파티션 정보

Creating 4 MTD partitions on "lpc32xx_nand":
0x00000000-0x00180000 : "phy3250-boot"
0x00180000-0x001c0000 : "phy3250-ubt-prms"
0x001c0000-0x005c0000 : "phy3250-kernel"
0x005c0000-0x08000000 : "phy3250-rootfs"

linux kernel 2.6.27.8에서 설정한다.

이 기능은 고분해능 타이머를 사용 할 수 있게 해 준다.

이 타이머는 나노초 단위로 작동한다.

해당하는 함수로는

void hrtimer_init( struct hrtimer *time, clockid_t which_clock, 
                                            enum hrtimer_mode mode );
int hrtimer_start(struct hrtimer *timer, ktime_t time, 
                                       const enum hrtimer_mode mode);
int hrtimer_cancel(struct hrtimer *timer);
int hrtimer_try_to_cancel(struct hrtimer *timer);
int hrtimer_callback_running(struct hrtimer *timer);

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/hrtimer.h>
#include <linux/ktime.h>

MODULE_LICENSE( "GPL" );

#define MS_TO_NS(x)	(x * 1E6L)

static struct hrtimer hr_timer;

enum hrtimer_restart my_hrtimer_callback( struct hrtimer *timer )
{
  printk( "my_hrtimer_callback called (%ld).\n", jiffies );

  return HRTIMER_NORESTART;
}

int init_module( void )
{
  ktime_t ktime;
  unsigned long delay_in_ms = 200L;

  printk("HR Timer module installing\n");

  ktime = ktime_set( 0, MS_TO_NS(delay_in_ms) );

  hrtimer_init( &hr_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL );
  
  hr_timer.function = &my_hrtimer_callback;

  printk( "Starting timer to fire in %ldms (%ld)\n", 
                                         delay_in_ms, jiffies );

  hrtimer_start( &hr_timer, ktime, HRTIMER_MODE_REL );

  return 0;
}

void cleanup_module( void )
{
  int ret;

  ret = hrtimer_cancel( &hr_timer );
  if (ret) printk("The timer was still in use...\n");

  printk("HR Timer module uninstalling\n");

  return;
}