April 2012 - kernelnewbies@kernelnewbies.org - Kernelnewbies Mailing Lists

Fwd: [RFC]Module problem
by harryxiyou April 17, 2012

April 17, 2012

---------- Forwarded message ---------- From: harryxiyou <harryxiyou(a)gmail.com> Date: Thu, Apr 5, 2012 at 4:20 PM Subject: [RFC]Module problem To: linux-kernel(a)vger.kernel.org Hi list, When i write an easy module for testing, it happens to me a problem, which is like this "Building modules, stage 2. MODPOST 0 modules". I can not find the *.ko file. My Module file is like this: hello.c #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> static int __init hello_init(void) { printk("<1> Hello World\n"); return 0; } static void __exit hello_exit(void) { printk("<1> Goodbey\n"); return ; } MODULE_LICENSE("GPL"); module_init(hello_init); module_exit(hello_exit); Makefile is like this: obj-m += hello.o all: make -C /usr/src/linux-headers-3.0.0-12-generic M=/home/sel/homeworl modules clean: make -C /usr/src/linux-headers-3.0.0-12-generic M=/home/sel/homeworl clean When i compile my modules as up Makefile, i cannot get my hello.ko file. However, when i change the Makefile like following it is ok for me. obj-m :=hello.o ifneq ($( KERNELRELEASE),) else KERNELDIR ?= /lib/modules/$(shell uname -r)/build PWD :=$(shell pwd) default: $(MAKE) -C $(KERNELDIR) M=$(PWD) modules endif I cannot understand this well Makefile clearly. Cloud anyone give me a help ;-) My kernel version is 2.6. Ubuntu 10.04. x86 32bits. -- Thanks Harry Wei -- Thanks Harry Wei

2 1

kernel panic after VFS mount in FPGA board
by pcuser p April 16, 2012

April 16, 2012

Hi, I'm doing kernel porting to arm926 based FPGA board,very minimal setup (uart + timer only) I'm getting kernel panic after cramfs root file system is mounted,I am expecting to enter login prompt after root file system is mounted. Below are the details #define PLAT_PHYS_OFFSET 0x80000000 (with 128 MB SDRAM) #define CONFIG_PAGE_OFFSET 0xc0000000 Physical memory : 128MB (0x80000000 to 88000000) ZRELADDR = 0x80008000 PARAMS_PHYS = 0x80000100 INITRD_PHYS = 0x80800000 Kernel cmd line : mem=32M console=ttySAC0,115200 root=/dev/ram0 rootfstype=cramfs init=/linuxrc initrd=0x80800000,8M user_debug=31 executables in cramfs (/bin) are built with busy box with all libraries statically linked. *linuxrc init script* #!/bin/sh** /bin/echo "mount /etc as ramfs" /bin/mount -n -t ramfs ramfs /etc /bin/mount -n -t tmpfs tmpfs /tmp exec /sbin/init I tried with this init script,but kernel is hanging without any message.. I changed it a bit as below, to see if it reads the init script #!/bin/sh /bin/echo "Entering Init script" with this changes,I am expect to get print message "Entering Init script" after cramfs is mounted,but I am getting panic message which is attached below. Can some one suggest how to fix this.. *Kernel message:* *memory layout:* Virtual kernel memory layout: vector : 0xffff0000 - 0xffff1000 ( 4 kB) fixmap : 0xfff00000 - 0xfffe0000 ( 896 kB) DMA : 0xffc00000 - 0xffe00000 ( 2 MB) vmalloc : 0xc2800000 - 0xf6000000 ( 824 MB) lowmem : 0xc0000000 - 0xc2000000 ( 32 MB) modules : 0xbf000000 - 0xc0000000 ( 16 MB) .text : 0xc0008000 - 0xc0169000 (1412 kB) .init : 0xc0169000 - 0xc017d000 ( 80 kB) .data : 0xc017e000 - 0xc018b720 ( 54 kB) .bss : 0xc018b744 - 0xc019c6fc ( 68 kB) RAMDISK: cramfs filesystem found at block 0 RAMDISK: Loading 5868KiB [1 disk] into ram disk... - done. VFS: Mounted root (cramfs filesystem) readonly on device 1:0. Freeing init memory: 80K *Panic message:* Kernel panic - not syncing: Attempted to kill init! Backtrace: [<c000c378>] (dump_backtrace+0x0/0x10c) from [<c000c49c>] (dump_stack+0x18/0x1c) r6:c1822000 r5:c018bb40 r4:c018bb60 r3:60000013 [<c000c484>] (dump_stack+0x0/0x1c) from [<c0017d3c>] (panic+0x64/0x1b0) [<c0017cd8>] (panic+0x0/0x1b0) from [<c001b5d8>] (do_exit+0x2b8/0x6b4) r3:c0184294 r2:00000000 r1:00000001 r0:c014f394 r7:c1822000 [<c001b320>] (do_exit+0x0/0x6b4) from [<c001bd3c>] (do_group_exit+0xd8/0xe0) r7:000000f8 [<c001bc64>] (do_group_exit+0x0/0xe0) from [<c001bd5c>] (sys_exit_group+0x18/0x20) r4:0008eba4 r3:00000000 [<c001bd44>] (sys_exit_group+0x0/0x20) from [<c0009460>] (ret_fast_syscall+0x0/0x2c)

2 2

[RFC] Kernel API
by harryxiyou April 14, 2012

April 14, 2012

Hi everyone, I'd like to know how i can get all the Kernel APIs, which i can call ones i need in my Kernel Modules. Sometimes, i wanna use some Kenrel APIS as the userspace i can use 'man api', which i can understand it and use it. But i have not find the way to search a Kernel API easily. Cloud anyone give me some advices? -- Thanks Harry Wei

3 4

[RFC]Something wrong with my module
by harryxiyou April 13, 2012

April 13, 2012

Hi greg, I write a module for inserting a PCB or delete a PCB to kernel's PCB tree, but when i run it something wrong happens to me like following. My environment is "Linux 10 2.6.35-22-generic #33-Ubuntu SMP Sun Sep 19 20:34:50 UTC 2010 i686 GNU/Linux" hw2.c #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/sched.h> #include <linux/list.h> #include <linux/slab.h> struct pcb { int pid; int state; int flag; char *comm; struct list_head tasks; }; static int insert_task(struct task_struct *p) { struct pcb *pcb1 = NULL; pcb1 = (struct pcb *)kmalloc(sizeof(struct pcb), GFP_KERNEL); if (NULL == pcb1) { printk("<0> kmalloc failed!\n"); } pcb1->state = 8; pcb1->flag = 8; pcb1->pid= 2; pcb1->comm = "jiawei"; list_add(&pcb1->tasks, &p->tasks); return 0; } static int rm_task(struct task_struct *p){ struct task_struct *del = p; list_del(&p->tasks); // kfree(del); return 0; } #if 1 static int print_pid(void) { struct task_struct *task = NULL; struct task_struct *p = NULL; struct list_head *pos = NULL; int count = 0; printk("Search for insert task-------->\n"); task = &init_task; list_for_each(pos, &task->tasks) { p = list_entry(pos, struct task_struct, tasks); count++; if (0 == p->pid) { rm_task(p); } printk("pid: %d, state: %ld, comm: %s\n", p->pid, p->state, p->comm); } insert_task(p); printk("the number of process is %d\n", count); count = 0; printk("show all tasks-------->\n"); task = &init_task; list_for_each(pos, &task->tasks) { p = list_entry(pos, struct task_struct, tasks); count++; printk("pid: %d, state: %ld, comm: %s\n", p->pid, p->state, p->comm); } printk("the number of process is %d\n", count); return 0; } #endif static int __init hello_init(void) { printk("<1> Hello World\n"); print_pid(); return 0; } static void __exit hello_exit(void) { printk("<1> Goodbey\n"); return ; } MODULE_LICENSE("GPL"); module_init(hello_init); module_exit(hello_exit); Dmesg logs: [ 1174.738305] Search for insert task--------> [ 1174.738308] pid: 1, state: 1, comm: init [ 1174.738312] pid: 2, state: 1, comm: kthreadd [ 1174.738316] pid: 3, state: 1, comm: ksoftirqd/0 [ 1174.738319] pid: 4, state: 1, comm: migration/0 [ 1174.738323] pid: 5, state: 1, comm: watchdog/0 [ 1174.738326] pid: 6, state: 1, comm: events/0 [ 1174.738329] pid: 7, state: 1, comm: cpuset [ 1174.738333] pid: 8, state: 1, comm: khelper [ 1174.738336] pid: 9, state: 1, comm: netns [ 1174.738340] pid: 10, state: 1, comm: async/mgr [ 1174.738343] pid: 11, state: 1, comm: pm [ 1174.738346] pid: 12, state: 1, comm: sync_supers [ 1174.738350] pid: 13, state: 1, comm: bdi-default [ 1174.738353] pid: 14, state: 1, comm: kintegrityd/0 [ 1174.738357] pid: 15, state: 1, comm: kblockd/0 [ 1174.738360] pid: 16, state: 1, comm: ata_aux [ 1174.738364] pid: 17, state: 1, comm: ata_sff/0 [ 1174.738367] pid: 18, state: 1, comm: khubd [ 1174.738370] pid: 19, state: 1, comm: kseriod [ 1174.738374] pid: 20, state: 1, comm: kmmcd [ 1174.738377] pid: 23, state: 1, comm: kswapd0 [ 1174.738380] pid: 24, state: 1, comm: ksmd [ 1174.738383] pid: 25, state: 1, comm: aio/0 [ 1174.738387] pid: 26, state: 1, comm: ecryptfs-kthrea [ 1174.738390] pid: 27, state: 1, comm: crypto/0 [ 1174.738394] pid: 33, state: 1, comm: scsi_eh_0 [ 1174.738397] pid: 35, state: 1, comm: scsi_eh_1 [ 1174.738400] pid: 38, state: 1, comm: kstriped [ 1174.738404] pid: 39, state: 1, comm: kmpathd/0 [ 1174.738407] pid: 40, state: 1, comm: kmpath_handlerd [ 1174.738411] pid: 41, state: 1, comm: ksnapd [ 1174.738414] pid: 42, state: 1, comm: kondemand/0 [ 1174.738417] pid: 43, state: 1, comm: kconservative/0 [ 1174.738421] pid: 147, state: 1, comm: scsi_eh_2 [ 1174.738424] pid: 148, state: 1, comm: scsi_eh_3 [ 1174.738427] pid: 160, state: 1, comm: jbd2/sda1-8 [ 1174.738431] pid: 161, state: 1, comm: ext4-dio-unwrit [ 1174.738434] pid: 194, state: 1, comm: flush-8:0 [ 1174.738438] pid: 223, state: 1, comm: upstart-udev-br [ 1174.738441] pid: 225, state: 1, comm: udevd [ 1174.738445] pid: 284, state: 1, comm: udevd [ 1174.738448] pid: 289, state: 1, comm: udevd [ 1174.738451] pid: 323, state: 1, comm: kpsmoused [ 1174.738455] pid: 477, state: 1, comm: hd-audio0 [ 1174.738458] pid: 502, state: 1, comm: sshd [ 1174.738462] pid: 506, state: 1, comm: rsyslogd [ 1174.738465] pid: 529, state: 1, comm: dbus-daemon [ 1174.738469] pid: 561, state: 1, comm: gdm-binary [ 1174.738472] pid: 566, state: 1, comm: NetworkManager [ 1174.738476] pid: 577, state: 1, comm: avahi-daemon [ 1174.738479] pid: 586, state: 1, comm: avahi-daemon [ 1174.738483] pid: 587, state: 1, comm: modem-manager [ 1174.738486] pid: 597, state: 1, comm: console-kit-dae [ 1174.738490] pid: 675, state: 1, comm: gdm-simple-slav [ 1174.738493] pid: 679, state: 1, comm: cupsd [ 1174.738497] pid: 684, state: 1, comm: wpa_supplicant [ 1174.738501] pid: 688, state: 1, comm: dhclient [ 1174.738504] pid: 707, state: 1, comm: Xorg [ 1174.738507] pid: 742, state: 1, comm: getty [ 1174.738511] pid: 748, state: 1, comm: getty [ 1174.738514] pid: 758, state: 1, comm: getty [ 1174.738517] pid: 760, state: 1, comm: getty [ 1174.738520] pid: 764, state: 1, comm: getty [ 1174.738524] pid: 766, state: 1, comm: acpid [ 1174.738527] pid: 771, state: 1, comm: cron [ 1174.738530] pid: 772, state: 1, comm: atd [ 1174.738534] pid: 909, state: 1, comm: dbus-launch [ 1174.738537] pid: 978, state: 1, comm: gdm-session-wor [ 1174.738541] pid: 986, state: 1, comm: upowerd [ 1174.738544] pid: 990, state: 1, comm: rtkit-daemon [ 1174.738548] pid: 1000, state: 1, comm: polkitd [ 1174.738551] pid: 1071, state: 1, comm: getty [ 1174.738555] pid: 1082, state: 1, comm: gnome-keyring-d [ 1174.738559] pid: 1101, state: 1, comm: gnome-session [ 1174.738562] pid: 1128, state: 1, comm: ibus-daemon [ 1174.738566] pid: 1132, state: 1, comm: ssh-agent [ 1174.738569] pid: 1135, state: 1, comm: dbus-launch [ 1174.738573] pid: 1136, state: 1, comm: dbus-daemon [ 1174.738576] pid: 1142, state: 1, comm: gconfd-2 [ 1174.738580] pid: 1146, state: 1, comm: gnome-power-man [ 1174.738583] pid: 1152, state: 1, comm: gnome-settings- [ 1174.738587] pid: 1157, state: 1, comm: gvfsd [ 1174.738590] pid: 1162, state: 1, comm: gvfs-fuse-daemo [ 1174.738593] pid: 1170, state: 1, comm: polkit-gnome-au [ 1174.738597] pid: 1172, state: 1, comm: pulseaudio [ 1174.738600] pid: 1173, state: 1, comm: bluetooth-apple [ 1174.738604] pid: 1176, state: 1, comm: evolution-alarm [ 1174.738608] pid: 1177, state: 1, comm: nm-applet [ 1174.738611] pid: 1178, state: 1, comm: gnome-panel [ 1174.738615] pid: 1180, state: 1, comm: metacity [ 1174.738618] pid: 1182, state: 1, comm: nautilus [ 1174.738621] pid: 1189, state: 1, comm: gconf-helper [ 1174.738625] pid: 1202, state: 1, comm: ibus-gconf [ 1174.738629] pid: 1204, state: 1, comm: python [ 1174.738632] pid: 1206, state: 1, comm: ibus-x11 [ 1174.738635] pid: 1214, state: 1, comm: ibus-engine-pin [ 1174.738639] pid: 1226, state: 1, comm: gvfs-gdu-volume [ 1174.738642] pid: 1249, state: 1, comm: udisks-daemon [ 1174.738646] pid: 1271, state: 1, comm: udisks-daemon [ 1174.738649] pid: 1279, state: 1, comm: gvfs-afc-volume [ 1174.738653] pid: 1281, state: 1, comm: gvfsd-trash [ 1174.738656] pid: 1284, state: 1, comm: gvfs-gphoto2-vo [ 1174.738660] pid: 1289, state: 1, comm: gnome-screensav [ 1174.738663] pid: 1291, state: 1, comm: bonobo-activati [ 1174.738667] pid: 1299, state: 1, comm: wnck-applet [ 1174.738670] pid: 1301, state: 1, comm: trashapplet [ 1174.738674] pid: 1313, state: 1, comm: indicator-apple [ 1174.738677] pid: 1317, state: 1, comm: clock-applet [ 1174.738681] pid: 1318, state: 1, comm: indicator-apple [ 1174.738684] pid: 1319, state: 1, comm: notification-ar [ 1174.738688] pid: 1329, state: 1, comm: indicator-me-se [ 1174.738691] pid: 1333, state: 1, comm: indicator-sessi [ 1174.738695] pid: 1337, state: 1, comm: gvfsd-burn [ 1174.738698] pid: 1343, state: 1, comm: indicator-messa [ 1174.738702] pid: 1347, state: 1, comm: indicator-appli [ 1174.738705] pid: 1349, state: 1, comm: indicator-sound [ 1174.738709] pid: 1350, state: 1, comm: gdu-notificatio [ 1174.738712] pid: 1353, state: 1, comm: gnome-terminal [ 1174.738716] pid: 1356, state: 1, comm: gnome-pty-helpe [ 1174.738719] pid: 1357, state: 1, comm: bash [ 1174.738722] pid: 1381, state: 1, comm: firefox [ 1174.738726] pid: 1385, state: 1, comm: run-mozilla.sh [ 1174.738729] pid: 1389, state: 1, comm: firefox-bin [ 1174.738733] pid: 1419, state: 1, comm: applet.py [ 1174.738736] pid: 1427, state: 1, comm: sshd [ 1174.738740] pid: 1519, state: 1, comm: sshd [ 1174.738743] pid: 1520, state: 1, comm: bash [ 1174.738746] pid: 1557, state: 1, comm: update-notifier [ 1174.738750] pid: 1561, state: 1, comm: sshd [ 1174.738753] pid: 1657, state: 1, comm: sshd [ 1174.738756] pid: 1658, state: 1, comm: bash [ 1174.738760] pid: 1671, state: 1, comm: sshd [ 1174.738763] pid: 1784, state: 1, comm: sshd [ 1174.738766] pid: 1785, state: 1, comm: bash [ 1174.738769] pid: 1812, state: 1, comm: sshd [ 1174.738773] pid: 1911, state: 1, comm: sshd [ 1174.738776] pid: 1912, state: 1, comm: bash [ 1174.738779] pid: 1925, state: 1, comm: sshd [ 1174.738783] pid: 2038, state: 1, comm: sshd [ 1174.738786] pid: 2039, state: 1, comm: bash [ 1174.738789] pid: 2170, state: 1, comm: su [ 1174.738792] pid: 2177, state: 1, comm: bash [ 1174.738796] pid: 2285, state: 1, comm: vim [ 1174.738799] pid: 2319, state: 1, comm: vim [ 1174.738802] pid: 2320, state: 1, comm: sshd [ 1174.738806] pid: 2413, state: 1, comm: bash [ 1174.738809] pid: 2456, state: 1, comm: man [ 1174.738812] pid: 2465, state: 1, comm: pager [ 1174.738816] pid: 2474, state: 1, comm: su [ 1174.738819] pid: 2481, state: 1, comm: bash [ 1174.738822] pid: 0, state: 1, comm: [ 1174.738840] BUG: unable to handle kernel paging request at 00100100 [ 1174.738845] IP: [<f072a08d>] hello_init+0x8d/0x1c8 [hw2] [ 1174.738853] *pde = 00000000 [ 1174.738857] Oops: 0000 [#3] SMP [ 1174.738860] last sysfs file: /sys/devices/pci0000:00/0000:00:03.3/usb1/1-0:1.0/uevent [ 1174.738865] Modules linked in: hw2(+) hw1(+) binfmt_misc parport_pc ppdev snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device snd sis_agp psmouse serio_raw soundcore snd_page_alloc shpchp agpgart lp parport 8139too 8139cp sata_sis mii [last unloaded: hw1] [ 1174.738895] [ 1174.738900] Pid: 4340, comm: insmod Tainted: G D 2.6.35-22-generic #33-Ubuntu / [ 1174.738904] EIP: 0060:[<f072a08d>] EFLAGS: 00010292 CPU: 0 [ 1174.738908] EIP is at hello_init+0x8d/0x1c8 [hw2] [ 1174.738911] EAX: 0000002b EBX: 00100100 ECX: c07cdd3c EDX: 00000000 [ 1174.738914] ESI: d85650e0 EDI: 00000097 EBP: d8781f5c ESP: d8781f34 [ 1174.738917] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 [ 1174.738921] Process insmod (pid: 4340, ti=d8780000 task=ef098000 task.ti=d8780000) [ 1174.738923] Stack: [ 1174.738925] f07210d8 00000000 00000001 d85653d0 00000001 c07d0f50 00000001 096bb018 [ 1174.738933] <0> f0721120 00000000 d8781f88 c0101132 f0721120 c07d0f60 096bb018 f0721120 [ 1174.738940] <0> 00004000 f072a000 096bb018 f0721120 00004000 d8781fac c0180c2b 00000003 [ 1174.738948] Call Trace: [ 1174.738958] [<c0101132>] ? do_one_initcall+0x32/0x1a0 [ 1174.738963] [<f072a000>] ? hello_init+0x0/0x1c8 [hw2] [ 1174.738969] [<c0180c2b>] ? sys_init_module+0x9b/0x1e0 [ 1174.738975] [<c02169c5>] ? sys_close+0x75/0xc0 [ 1174.738982] [<c05c90a4>] ? syscall_call+0x7/0xb [ 1174.738984] Code: 00 00 00 02 20 00 8b 16 8d 8e f0 02 00 00 83 c7 01 89 4c 24 0c 89 44 24 04 c7 04 24 d8 10 72 f0 89 54 24 08 e8 b0 c3 e9 cf 8b 1b <8b> 03 0f 18 00 90 81 fb 90 78 7c c0 75 92 ba d0 00 00 00 b8 68 [ 1174.739024] EIP: [<f072a08d>] hello_init+0x8d/0x1c8 [hw2] SS:ESP 0068:d8781f34 [ 1174.739030] CR2: 0000000000100100 [ 1174.739035] ---[ end trace babb4642fde28352 ]--- [ 1620.965086] ------------[ cut here ]------------ [ 1620.965105] WARNING: at /build/buildd/linux-2.6.35/net/sched/sch_generic.c:258 dev_watchdog+0x1fd/0x210() [ 1620.965109] NETDEV WATCHDOG: eth1 (8139too): transmit queue 0 timed out [ 1620.965112] Modules linked in: hw2(+) hw1(+) binfmt_misc parport_pc ppdev snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device snd sis_agp psmouse serio_raw soundcore snd_page_alloc shpchp agpgart lp parport 8139too 8139cp sata_sis mii [last unloaded: hw1] [ 1620.965147] Pid: 0, comm: swapper Tainted: G D 2.6.35-22-generic #33-Ubuntu [ 1620.965150] Call Trace: [ 1620.965160] [<c014ac52>] warn_slowpath_common+0x72/0xa0 [ 1620.965166] [<c050e62d>] ? dev_watchdog+0x1fd/0x210 [ 1620.965170] [<c050e62d>] ? dev_watchdog+0x1fd/0x210 [ 1620.965175] [<c014ad23>] warn_slowpath_fmt+0x33/0x40 [ 1620.965179] [<c050e62d>] dev_watchdog+0x1fd/0x210 [ 1620.965185] [<c0108a28>] ? sched_clock+0x8/0x10 [ 1620.965191] [<c016bf14>] ? sched_clock_local+0xa4/0x180 [ 1620.965195] [<c050e430>] ? dev_watchdog+0x0/0x210 [ 1620.965200] [<c0157e1f>] call_timer_fn+0x2f/0xf0 [ 1620.965204] [<c0169a5a>] ? hrtimer_run_pending+0x4a/0xe0 [ 1620.965209] [<c0159064>] run_timer_softirq+0x104/0x210 [ 1620.965213] [<c016c121>] ? sched_clock_cpu+0x131/0x190 [ 1620.965217] [<c050e430>] ? dev_watchdog+0x0/0x210 [ 1620.965222] [<c015127c>] __do_softirq+0x9c/0x1b0 [ 1620.965226] [<c0158af3>] ? update_process_times+0x53/0x70 [ 1620.965230] [<c01513d5>] do_softirq+0x45/0x50 [ 1620.965234] [<c0151545>] irq_exit+0x65/0x70 [ 1620.965239] [<c05cf72b>] smp_apic_timer_interrupt+0x5b/0x8a [ 1620.965243] [<c016c1ce>] ? sched_clock_idle_sleep_event+0xe/0x10 [ 1620.965248] [<c05c9535>] apic_timer_interrupt+0x31/0x38 [ 1620.965254] [<c010a766>] ? mwait_idle+0x56/0xb0 [ 1620.965257] [<c0101fcc>] cpu_idle+0x8c/0xd0 [ 1620.965262] [<c05b2431>] rest_init+0x71/0x80 [ 1620.965269] [<c081981a>] start_kernel+0x36e/0x374 [ 1620.965273] [<c08199dd>] ? pass_all_bootoptions+0x0/0xa [ 1620.965277] [<c08190d7>] i386_start_kernel+0xd7/0xdf [ 1620.965280] ---[ end trace babb4642fde28353 ]--- Cloud you please give me some help? -- Thanks Harry Wei

4 10

CP210x module didn't receive data
by पारस April 13, 2012

April 13, 2012

Hi All, I added support for Silicon Labs CP210x to my development board kernel. On my development board CP210x chip is connected using USB bus. And I am sending data to CP210x using one external device. I write a program to read data on usb-serial (ttyUSB0) on development board. But I didn't get any data, --------------- --------- --------------------------- | external |-------> | CP210x | -------> | my developemnt | | device | | | | device | enable debug messages ----------------------------------------------------------------------------------------------------------------------------------------- # echo 1 > /sys/bus/usb-serial/drivers/generic/module/parameters/debug # cat /sys/bus/usb-serial/drivers/generic/module/parameters/debug Y # echo 1 > /sys/bus/usb-serial/drivers/cp210x/module/parameters/debug # cat /sys/bus/usb-serial/drivers/cp210x/module/parameters/debug Y ----------------------------------------------------------------------------------------------------------------------------------------- debug messages #demesg .... ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver ar71xx-ohci ar71xx-ohci: Atheros AR71xx built-in OHCI controller ar71xx-ohci ar71xx-ohci: new USB bus registered, assigned bus number 1 ar71xx-ohci ar71xx-ohci: irq 3, io mem 0x1b000000 usb usb1: configuration #1 chosen from 1 choice hub 1-0:1.0: USB hub found hub 1-0:1.0: 1 port detected usbcore: registered new interface driver usbserial USB Serial support registered for generic usbcore: registered new interface driver usbserial_generic usbserial: USB Serial Driver core Initializing USB Mass Storage driver... usbcore: registered new interface driver usb-storage USB Mass Storage support registered. usb 1-1: new full speed USB device using ar71xx-ohci and address 2 USB Serial support registered for cp210x usbcore: registered new interface driver cp210x cp210x: v0.09:Silicon Labs CP210x RS232 serial adaptor driver USB Serial support registered for pl2303 usbcore: registered new interface driver pl2303 pl2303: Prolific PL2303 USB to serial adaptor driver usb 1-1: configuration #1 chosen from 1 choice cp210x 1-1:1.0: cp210x converter detected usb 1-1: reset full speed USB device using ar71xx-ohci and address 2 usb 1-1: cp210x converter now attached to ttyUSB0 ...... ----------------------------------------------------------------------------------------------------------------------------------------- When I open ttyUSB0 for communication, debug messages are ----------------------------------------------------------------------------------------------------------------------------------------- #dmesg ... drivers/usb/serial/usb-serial.c: serial_install drivers/usb/serial/usb-serial.c: serial_open - port 0 drivers/usb/serial/cp210x.c: cp210x_open - port 0 drivers/usb/serial/cp210x.c: cp210x_get_termios_port - port 0 drivers/usb/serial/cp210x.c: cp210x_get_termios_port - baud rate = 115200 drivers/usb/serial/cp210x.c: cp210x_get_termios_port - data bits = 8 drivers/usb/serial/cp210x.c: cp210x_get_termios_port - parity = NONE drivers/usb/serial/cp210x.c: cp210x_get_termios_port - stop bits = 1 drivers/usb/serial/cp210x.c: cp210x_get_termios_port - flow control = NONE drivers/usb/serial/cp210x.c: cp210x_tiocmset_port - port 0 drivers/usb/serial/cp210x.c: cp210x_tiocmset_port - control = 0x0303 ..... ----------------------------------------------------------------------------------------------------------------------------------------- The debug messages I get when I send data from external device to developemnt board, ----------------------------------------------------------------------------------------------------------------------------------------- #demesg .... drivers/usb/serial/usb-serial.c: serial_write_room - port 0 drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [5E] drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [40] drivers/usb/serial/usb-serial.c: serial_write_room - port 0 drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [5E] drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [40] drivers/usb/serial/usb-serial.c: serial_write_room - port 0 drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [5E] drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [40] drivers/usb/serial/usb-serial.c: serial_write_room - port 0 drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [5E] drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [40] drivers/usb/serial/usb-serial.c: serial_write_room - port 0 drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [5E] drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [40] drivers/usb/serial/usb-serial.c: serial_write_room - port 0 drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [5E] drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [40] drivers/usb/serial/usb-serial.c: serial_write_room - port 0 drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [5E] drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [40] drivers/usb/serial/usb-serial.c: serial_write_room - port 0 drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [5E] drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [40] drivers/usb/serial/usb-serial.c: usb_serial_port_work - port 0 drivers/usb/serial/usb-serial.c: usb_serial_port_work - port 0 drivers/usb/serial/usb-serial.c: serial_write_room - port 0 drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [5E] drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [40] drivers/usb/serial/usb-serial.c: serial_write_room - port 0 drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [5E] drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [40] drivers/usb/serial/usb-serial.c: serial_write_room - port 0 drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [5E] drivers/usb/serial/usb-serial.c: serial_write - port 0, 1 byte(s) data [40] drivers/usb/serial/usb-serial.c: usb_serial_port_work - port 0 drivers/usb/serial/usb-serial.c: usb_serial_port_work - port 0 drivers/usb/serial/usb-serial.c: usb_serial_port_work - port 0 ----------------------------------------------------------------------------------------------------------------------------------------- Program to read data from ttyUSB0, running on development board ----------------------------------------------------------------------------------------------------------------------------------------- int main(void) { int UartFd; char ReadData[30]; int ReturnVal; UartFd = open("/dev/ttyUSB0", O_RDONLY); if ( UartFd < 0 ) { perror("Open"); } else { printf("Uart_Fd: %d\r\n", UartFd); } memset(ReadData, 0, sizeof(ReadData)); ReturnVal = read(UartFd, ReadData, sizeof(ReadData)); if ( ReturnVal < 0 ) { perror("Read"); } else { printf("ReturnVal: %d\r\n", ReturnVal); int i; for(i = 0; i < ReturnVal; i++) printf(" %2X ", ReadData[i]); } close(UartFd); return 0; } ----------------------------------------------------------------------------------------------------------------------------------------- My program didn't print any data on terminal. Is any body help me how to debug this issue, what is the problem. Thanks in advance, Thanks, Paras

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Issue in uncompressing zImage
by KARTHIK SEKURU April 13, 2012

April 13, 2012

Hi, I'm doing kernel porting to arm926 based FPGA board,very minimal setup (uart + timer only) I'm getting kernel panic after cramfs root file system is mounted,I am expecting to enter login prompt after root file system is mounted. Below are the details #define PLAT_PHYS_OFFSET 0x80000000 (with 128 MB SDRAM) #define CONFIG_PAGE_OFFSET 0xc0000000 Physical memory : 128MB (0x80000000 to 88000000) ZRELADDR = 0x80008000 PARAMS_PHYS = 0x80000100 INITRD_PHYS = 0x80800000 Kernel cmd line : mem=32M console=ttySAC0,115200 root=/dev/ram0 rootfstype=cramfs init=/linuxrc initrd=0x80800000,8M user_debug=31 I am not using u-boot and doing all the required initializations through trace32 cmm script. After compiling the kernel, when I load vmlinux(through trace32) at 0x80008000, the kernel runs upto mounting the filesystem(though there is some issue in mounting the filesystem). But when I load zImage at the same address i.e 0x80008000, I am getting *Uncompressing Linux...* * * *uncompression error* * * * -- System halted* in the console. I made sure that I am enabling the config options CONFIG_XZ_DEC (xz decompression support) through menuconfig. I suspected on the cramfs memory location and then tried loading only zImage at 0x80008000.,even after this the result is same. Please let me know where could be the issue.

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System Tap help
by V.Ravikumar April 12, 2012

April 12, 2012

Hi all, I'm probing sys_write system call using system tap to get modified file name along with UID. Here is code snippet. probe kernel.function ("vfs_write") { filename = user_string($file->f_dentry->d_name->name) // for 2.6.18 kernel. printf ("%d %s\n",uid,filename) } I got sample program to get inode number as below inode_nr = $file->f_path->dentry->d_inode->i_ino . This I changed to get file name, I'm getting file name as empty. With above program i'm getting file name as unknown. My question is does above code snippet is correct to get file name ? If not could somebody please let me know the correct implementation.

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IRQs and memory consistency
by Christopher Harvey April 11, 2012

April 11, 2012

This is a high level question about how IRQs work in the kernel. I have a struct that was kmalloc'd into ram. Within this struct there is an int, called devid. When I set this devid to a number that isn't 0, I print the following: checking devid value....327683 in 0xcb6953d4 where 327683 is the value of the int and 0xcb6953d4 is the address of the struct that the devid value is in. Then an interrupt happens and when I print this value again at the beginning of the interrupt handler I get the following printed text: checking devid value....0 in 0xcb6953d4 notice that the devid has been set to 0. I can't find any code on my end that would do this. Is there something, maybe related to memory address spaces in IRQ handlers that I don't know about? The IRQ and the setting of the devid value happen fairly close to each other in time. (like less than a second, or closer) Any ideas or guesses are appreciated. -Chris

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TinyLinux project status
by Ezequiel García April 11, 2012

April 11, 2012

Hello, I would like to know what is the current status of the tiny linux project? (The current goals, status and activeness). I've found this: http://elinux.org/Linux_Tiny but it seems a bit outdated. Also, I would like to know what's the smaller kernel (static and dynamic memory footprint) that can be achieved right now (without losing signicant funcionality). Is it possible to run linux a 1 MB SRAM board (no DRAM) ? (I am thinking at a ARM7 LPC2294 header board). Thanks a lot, Ezequiel.

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A problem about irq.
by 夏业添 April 11, 2012

April 11, 2012

Hi, Recently, I am trying to test event channel on Xen. I write a module alloc an event channel and try to bind this channel to an irq handler. But every time I insmod the module, the kernel says that the action of binding fails. I use a function defined in drivers/xen/events.c like this: bind_evtchn_to_irqhandler(args.port,server_handler,IRQF_DISABLED,NULL,NULL); And I must admit that I have very few knowledge of the interrupt handler stuff and whether the last two parameters can be set NULL. So here are two problem: 1)I really need some simple instruction and sample code about both the interrupt handler and, especially, xen event channel. 2)And there is other odd thing. I try to check the bind_evtchn_to_irqhandler, finding that it finally calls request_irq()<http://www.codebrowse.net/source/xref/linux-3.0/include/linux/interrupt.h#r…>, which calls request_threaded_irq()<http://www.codebrowse.net/source/xref/linux-3.0/include/linux/interrupt.h#r…>, which calls request_irq() again. But in another website, I find the request_threaded_irq()<http://tomoyo.sourceforge.jp/cgi-bin/lxr/source/kernel/irq/manage.c#L1346>defined in the kernel/irq/manage.c#L1346. I'm totally confused. Sorry for my poor English. If anyone knows the answer, please tell me. Thanks a lot!

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