diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/DocBook/kernel-api.tmpl | 8 | ||||
| -rw-r--r-- | Documentation/debugging-via-ohci1394.txt | 179 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 51 | ||||
| -rw-r--r-- | Documentation/lguest/lguest.c | 49 | ||||
| -rw-r--r-- | Documentation/x86_64/boot-options.txt | 8 | ||||
| -rw-r--r-- | Documentation/x86_64/uefi.txt | 9 |
6 files changed, 294 insertions, 10 deletions
diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl index aa38cc5..77436d7 100644 --- a/Documentation/DocBook/kernel-api.tmpl +++ b/Documentation/DocBook/kernel-api.tmpl @@ -419,7 +419,13 @@ X!Edrivers/pnp/system.c <chapter id="blkdev"> <title>Block Devices</title> -!Eblock/ll_rw_blk.c +!Eblock/blk-core.c +!Eblock/blk-map.c +!Iblock/blk-sysfs.c +!Eblock/blk-settings.c +!Eblock/blk-exec.c +!Eblock/blk-barrier.c +!Eblock/blk-tag.c </chapter> <chapter id="chrdev"> diff --git a/Documentation/debugging-via-ohci1394.txt b/Documentation/debugging-via-ohci1394.txt new file mode 100644 index 0000000..de4804e --- /dev/null +++ b/Documentation/debugging-via-ohci1394.txt @@ -0,0 +1,179 @@ + + Using physical DMA provided by OHCI-1394 FireWire controllers for debugging + --------------------------------------------------------------------------- + +Introduction +------------ + +Basically all FireWire controllers which are in use today are compliant +to the OHCI-1394 specification which defines the controller to be a PCI +bus master which uses DMA to offload data transfers from the CPU and has +a "Physical Response Unit" which executes specific requests by employing +PCI-Bus master DMA after applying filters defined by the OHCI-1394 driver. + +Once properly configured, remote machines can send these requests to +ask the OHCI-1394 controller to perform read and write requests on +physical system memory and, for read requests, send the result of +the physical memory read back to the requester. + +With that, it is possible to debug issues by reading interesting memory +locations such as buffers like the printk buffer or the process table. + +Retrieving a full system memory dump is also possible over the FireWire, +using data transfer rates in the order of 10MB/s or more. + +Memory access is currently limited to the low 4G of physical address +space which can be a problem on IA64 machines where memory is located +mostly above that limit, but it is rarely a problem on more common +hardware such as hardware based on x86, x86-64 and PowerPC. + +Together with a early initialization of the OHCI-1394 controller for debugging, +this facility proved most useful for examining long debugs logs in the printk +buffer on to debug early boot problems in areas like ACPI where the system +fails to boot and other means for debugging (serial port) are either not +available (notebooks) or too slow for extensive debug information (like ACPI). + +Drivers +------- + +The OHCI-1394 drivers in drivers/firewire and drivers/ieee1394 initialize +the OHCI-1394 controllers to a working state and can be used to enable +physical DMA. By default you only have to load the driver, and physical +DMA access will be granted to all remote nodes, but it can be turned off +when using the ohci1394 driver. + +Because these drivers depend on the PCI enumeration to be completed, an +initialization routine which can runs pretty early (long before console_init(), +which makes the printk buffer appear on the console can be called) was written. + +To activate it, enable CONFIG_PROVIDE_OHCI1394_DMA_INIT (Kernel hacking menu: +Provide code for enabling DMA over FireWire early on boot) and pass the +parameter "ohci1394_dma=early" to the recompiled kernel on boot. + +Tools +----- + +firescope - Originally developed by Benjamin Herrenschmidt, Andi Kleen ported +it from PowerPC to x86 and x86_64 and added functionality, firescope can now +be used to view the printk buffer of a remote machine, even with live update. + +Bernhard Kaindl enhanced firescope to support accessing 64-bit machines +from 32-bit firescope and vice versa: +- ftp://ftp.suse.de/private/bk/firewire/tools/firescope-0.2.2.tar.bz2 + +and he implemented fast system dump (alpha version - read README.txt): +- ftp://ftp.suse.de/private/bk/firewire/tools/firedump-0.1.tar.bz2 + +There is also a gdb proxy for firewire which allows to use gdb to access +data which can be referenced from symbols found by gdb in vmlinux: +- ftp://ftp.suse.de/private/bk/firewire/tools/fireproxy-0.33.tar.bz2 + +The latest version of this gdb proxy (fireproxy-0.34) can communicate (not +yet stable) with kgdb over an memory-based communication module (kgdbom). + +Getting Started +--------------- + +The OHCI-1394 specification regulates that the OHCI-1394 controller must +disable all physical DMA on each bus reset. + +This means that if you want to debug an issue in a system state where +interrupts are disabled and where no polling of the OHCI-1394 controller +for bus resets takes place, you have to establish any FireWire cable +connections and fully initialize all FireWire hardware __before__ the +system enters such state. + +Step-by-step instructions for using firescope with early OHCI initialization: + +1) Verify that your hardware is supported: + + Load the ohci1394 or the fw-ohci module and check your kernel logs. + You should see a line similar to + + ohci1394: fw-host0: OHCI-1394 1.1 (PCI): IRQ=[18] MMIO=[fe9ff800-fe9fffff] + ... Max Packet=[2048] IR/IT contexts=[4/8] + + when loading the driver. If you have no supported controller, many PCI, + CardBus and even some Express cards which are fully compliant to OHCI-1394 + specification are available. If it requires no driver for Windows operating + systems, it most likely is. Only specialized shops have cards which are not + compliant, they are based on TI PCILynx chips and require drivers for Win- + dows operating systems. + +2) Establish a working FireWire cable connection: + + Any FireWire cable, as long at it provides electrically and mechanically + stable connection and has matching connectors (there are small 4-pin and + large 6-pin FireWire ports) will do. + + If an driver is running on both machines you should see a line like + + ieee1394: Node added: ID:BUS[0-01:1023] GUID[0090270001b84bba] + + on both machines in the kernel log when the cable is plugged in + and connects the two machines. + +3) Test physical DMA using firescope: + + On the debug host, + - load the raw1394 module, + - make sure that /dev/raw1394 is accessible, + then start firescope: + + $ firescope + Port 0 (ohci1394) opened, 2 nodes detected + + FireScope + --------- + Target : <unspecified> + Gen : 1 + [Ctrl-T] choose target + [Ctrl-H] this menu + [Ctrl-Q] quit + + ------> Press Ctrl-T now, the output should be similar to: + + 2 nodes available, local node is: 0 + 0: ffc0, uuid: 00000000 00000000 [LOCAL] + 1: ffc1, uuid: 00279000 ba4bb801 + + Besides the [LOCAL] node, it must show another node without error message. + +4) Prepare for debugging with early OHCI-1394 initialization: + + 4.1) Kernel compilation and installation on debug target + + Compile the kernel to be debugged with CONFIG_PROVIDE_OHCI1394_DMA_INIT + (Kernel hacking: Provide code for enabling DMA over FireWire early on boot) + enabled and install it on the machine to be debugged (debug target). + + 4.2) Transfer the System.map of the debugged kernel to the debug host + + Copy the System.map of the kernel be debugged to the debug host (the host + which is connected to the debugged machine over the FireWire cable). + +5) Retrieving the printk buffer contents: + + With the FireWire cable connected, the OHCI-1394 driver on the debugging + host loaded, reboot the debugged machine, booting the kernel which has + CONFIG_PROVIDE_OHCI1394_DMA_INIT enabled, with the option ohci1394_dma=early. + + Then, on the debugging host, run firescope, for example by using -A: + + firescope -A System.map-of-debug-target-kernel + + Note: -A automatically attaches to the first non-local node. It only works + reliably if only connected two machines are connected using FireWire. + + After having attached to the debug target, press Ctrl-D to view the + complete printk buffer or Ctrl-U to enter auto update mode and get an + updated live view of recent kernel messages logged on the debug target. + + Call "firescope -h" to get more information on firescope's options. + +Notes +----- +Documentation and specifications: ftp://ftp.suse.de/private/bk/firewire/docs + +FireWire is a trademark of Apple Inc. - for more information please refer to: +http://en.wikipedia.org/wiki/FireWire diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 880f882..5d171b7 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -416,8 +416,21 @@ and is between 256 and 4096 characters. It is defined in the file [SPARC64] tick [X86-64] hpet,tsc - code_bytes [IA32] How many bytes of object code to print in an - oops report. + clearcpuid=BITNUM [X86] + Disable CPUID feature X for the kernel. See + include/asm-x86/cpufeature.h for the valid bit numbers. + Note the Linux specific bits are not necessarily + stable over kernel options, but the vendor specific + ones should be. + Also note that user programs calling CPUID directly + or using the feature without checking anything + will still see it. This just prevents it from + being used by the kernel or shown in /proc/cpuinfo. + Also note the kernel might malfunction if you disable + some critical bits. + + code_bytes [IA32/X86_64] How many bytes of object code to print + in an oops report. Range: 0 - 8192 Default: 64 @@ -570,6 +583,12 @@ and is between 256 and 4096 characters. It is defined in the file See drivers/char/README.epca and Documentation/digiepca.txt. + disable_mtrr_trim [X86, Intel and AMD only] + By default the kernel will trim any uncacheable + memory out of your available memory pool based on + MTRR settings. This parameter disables that behavior, + possibly causing your machine to run very slowly. + dmasound= [HW,OSS] Sound subsystem buffers dscc4.setup= [NET] @@ -660,6 +679,10 @@ and is between 256 and 4096 characters. It is defined in the file gamma= [HW,DRM] + gart_fix_e820= [X86_64] disable the fix e820 for K8 GART + Format: off | on + default: on + gdth= [HW,SCSI] See header of drivers/scsi/gdth.c. @@ -794,6 +817,16 @@ and is between 256 and 4096 characters. It is defined in the file for translation below 32 bit and if not available then look in the higher range. + io_delay= [X86-32,X86-64] I/O delay method + 0x80 + Standard port 0x80 based delay + 0xed + Alternate port 0xed based delay (needed on some systems) + udelay + Simple two microseconds delay + none + No delay + io7= [HW] IO7 for Marvel based alpha systems See comment before marvel_specify_io7 in arch/alpha/kernel/core_marvel.c. @@ -1059,6 +1092,11 @@ and is between 256 and 4096 characters. It is defined in the file Multi-Function General Purpose Timers on AMD Geode platforms. + mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when + the BIOS has incorrectly applied a workaround. TinyBIOS + version 0.98 is known to be affected, 0.99 fixes the + problem by letting the user disable the workaround. + mga= [HW,DRM] mousedev.tap_time= @@ -1159,6 +1197,8 @@ and is between 256 and 4096 characters. It is defined in the file nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. + noefi [X86-32,X86-64] Disable EFI runtime services support. + noexec [IA-64] noexec [X86-32,X86-64] @@ -1169,6 +1209,8 @@ and is between 256 and 4096 characters. It is defined in the file register save and restore. The kernel will only save legacy floating-point registers on task switch. + noclflush [BUGS=X86] Don't use the CLFLUSH instruction + nohlt [BUGS=ARM] no-hlt [BUGS=X86-32] Tells the kernel that the hlt @@ -1978,6 +2020,11 @@ and is between 256 and 4096 characters. It is defined in the file vdso=1: enable VDSO (default) vdso=0: disable VDSO mapping + vdso32= [X86-32,X86-64] + vdso32=2: enable compat VDSO (default with COMPAT_VDSO) + vdso32=1: enable 32-bit VDSO (default) + vdso32=0: disable 32-bit VDSO mapping + vector= [IA-64,SMP] vector=percpu: enable percpu vector domain diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index 9b0e322..6c8a238 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -79,6 +79,9 @@ static void *guest_base; /* The maximum guest physical address allowed, and maximum possible. */ static unsigned long guest_limit, guest_max; +/* a per-cpu variable indicating whose vcpu is currently running */ +static unsigned int __thread cpu_id; + /* This is our list of devices. */ struct device_list { @@ -153,6 +156,9 @@ struct virtqueue void (*handle_output)(int fd, struct virtqueue *me); }; +/* Remember the arguments to the program so we can "reboot" */ +static char **main_args; + /* Since guest is UP and we don't run at the same time, we don't need barriers. * But I include them in the code in case others copy it. */ #define wmb() @@ -554,7 +560,7 @@ static void wake_parent(int pipefd, int lguest_fd) else FD_CLR(-fd - 1, &devices.infds); } else /* Send LHREQ_BREAK command. */ - write(lguest_fd, args, sizeof(args)); + pwrite(lguest_fd, args, sizeof(args), cpu_id); } } @@ -1489,7 +1495,9 @@ static void setup_block_file(const char *filename) /* Create stack for thread and run it */ stack = malloc(32768); - if (clone(io_thread, stack + 32768, CLONE_VM, dev) == -1) + /* SIGCHLD - We dont "wait" for our cloned thread, so prevent it from + * becoming a zombie. */ + if (clone(io_thread, stack + 32768, CLONE_VM | SIGCHLD, dev) == -1) err(1, "Creating clone"); /* We don't need to keep the I/O thread's end of the pipes open. */ @@ -1499,7 +1507,21 @@ static void setup_block_file(const char *filename) verbose("device %u: virtblock %llu sectors\n", devices.device_num, cap); } -/* That's the end of device setup. */ +/* That's the end of device setup. :*/ + +/* Reboot */ +static void __attribute__((noreturn)) restart_guest(void) +{ + unsigned int i; + + /* Closing pipes causes the waker thread and io_threads to die, and + * closing /dev/lguest cleans up the Guest. Since we don't track all + * open fds, we simply close everything beyond stderr. */ + for (i = 3; i < FD_SETSIZE; i++) + close(i); + execv(main_args[0], main_args); + err(1, "Could not exec %s", main_args[0]); +} /*L:220 Finally we reach the core of the Launcher, which runs the Guest, serves * its input and output, and finally, lays it to rest. */ @@ -1511,7 +1533,8 @@ static void __attribute__((noreturn)) run_guest(int lguest_fd) int readval; /* We read from the /dev/lguest device to run the Guest. */ - readval = read(lguest_fd, ¬ify_addr, sizeof(notify_addr)); + readval = pread(lguest_fd, ¬ify_addr, + sizeof(notify_addr), cpu_id); /* One unsigned long means the Guest did HCALL_NOTIFY */ if (readval == sizeof(notify_addr)) { @@ -1521,16 +1544,23 @@ static void __attribute__((noreturn)) run_guest(int lguest_fd) /* ENOENT means the Guest died. Reading tells us why. */ } else if (errno == ENOENT) { char reason[1024] = { 0 }; - read(lguest_fd, reason, sizeof(reason)-1); + pread(lguest_fd, reason, sizeof(reason)-1, cpu_id); errx(1, "%s", reason); + /* ERESTART means that we need to reboot the guest */ + } else if (errno == ERESTART) { + restart_guest(); /* EAGAIN means the Waker wanted us to look at some input. * Anything else means a bug or incompatible change. */ } else if (errno != EAGAIN) err(1, "Running guest failed"); + /* Only service input on thread for CPU 0. */ + if (cpu_id != 0) + continue; + /* Service input, then unset the BREAK to release the Waker. */ handle_input(lguest_fd); - if (write(lguest_fd, args, sizeof(args)) < 0) + if (pwrite(lguest_fd, args, sizeof(args), cpu_id) < 0) err(1, "Resetting break"); } } @@ -1571,6 +1601,12 @@ int main(int argc, char *argv[]) /* If they specify an initrd file to load. */ const char *initrd_name = NULL; + /* Save the args: we "reboot" by execing ourselves again. */ + main_args = argv; + /* We don't "wait" for the children, so prevent them from becoming + * zombies. */ + signal(SIGCHLD, SIG_IGN); + /* First we initialize the device list. Since console and network * device receive input from a file descriptor, we keep an fdset * (infds) and the maximum fd number (max_infd) with the head of the @@ -1582,6 +1618,7 @@ int main(int argc, char *argv[]) devices.lastdev = &devices.dev; devices.next_irq = 1; + cpu_id = 0; /* We need to know how much memory so we can set up the device * descriptor and memory pages for the devices as we parse the command * line. So we quickly look through the arguments to find the amount diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt index 9453118..34abae4 100644 --- a/Documentation/x86_64/boot-options.txt +++ b/Documentation/x86_64/boot-options.txt @@ -110,12 +110,18 @@ Idle loop Rebooting - reboot=b[ios] | t[riple] | k[bd] [, [w]arm | [c]old] + reboot=b[ios] | t[riple] | k[bd] | a[cpi] | e[fi] [, [w]arm | [c]old] bios Use the CPU reboot vector for warm reset warm Don't set the cold reboot flag cold Set the cold reboot flag triple Force a triple fault (init) kbd Use the keyboard controller. cold reset (default) + acpi Use the ACPI RESET_REG in the FADT. If ACPI is not configured or the + ACPI reset does not work, the reboot path attempts the reset using + the keyboard controller. + efi Use efi reset_system runtime service. If EFI is not configured or the + EFI reset does not work, the reboot path attempts the reset using + the keyboard controller. Using warm reset will be much faster especially on big memory systems because the BIOS will not go through the memory check. diff --git a/Documentation/x86_64/uefi.txt b/Documentation/x86_64/uefi.txt index 91a98ed..7d77120 100644 --- a/Documentation/x86_64/uefi.txt +++ b/Documentation/x86_64/uefi.txt @@ -19,6 +19,10 @@ Mechanics: - Build the kernel with the following configuration. CONFIG_FB_EFI=y CONFIG_FRAMEBUFFER_CONSOLE=y + If EFI runtime services are expected, the following configuration should + be selected. + CONFIG_EFI=y + CONFIG_EFI_VARS=y or m # optional - Create a VFAT partition on the disk - Copy the following to the VFAT partition: elilo bootloader with x86_64 support, elilo configuration file, @@ -27,3 +31,8 @@ Mechanics: can be found in the elilo sourceforge project. - Boot to EFI shell and invoke elilo choosing the kernel image built in first step. +- If some or all EFI runtime services don't work, you can try following + kernel command line parameters to turn off some or all EFI runtime + services. + noefi turn off all EFI runtime services + reboot_type=k turn off EFI reboot runtime service |