Generic options for startup programs (QNX Neutrino)
Description:
All QNX Neutrino startup programs support the generic options described below.
There are additional options for the following architectures:
Note:
Individual startup programs can override these options and may support
additional board-specific options.
The order of precedence is as follows:
- board-specific options
- architecture-specific options
- generic options
Generic options
- -A
- Reboot the system on any abnormal termination of the kernel.
The default is to display information about the crash, and then halt.
- -C
- Clear (i.e., zero) any memory allocated by the startup library.
- -D channel[.channel_opts]
- Specify an output channel for debugging information.
The format of this option and the default value vary from board to board.
- -F [~]value
- Control the flags field in the cpuinfo section of the system page:
- value — OR the flags field with
value
- ~value — AND the flags field with
~value
For more information about the flags, see the
System Page
chapter of Building Embedded Systems.
- -f [cpu_freq][,[cycles_freq][,timer_freq]]
- Specify CPU frequencies.
All frequencies can be followed by H for hertz, K for kilohertz,
or M for megahertz (these suffixes aren't case-sensitive).
If no suffix is given, the library assumes megahertz if the number is less than 1000; otherwise it assumes hertz.
If they're specified, cpu_freq, cycles_freq, and
timer_freq are used to set the corresponding variables in the startup code:
- cpu_freq — the CPU clock frequency. It's also used
to set the speed field in the cpuinfo section of the system page.
- cycles_freq — the frequency at which the value returned by
ClockCycles() increments. It's also used to set the
cycles_per_sec field in the qtime section of the system page.
- timer_freq — the frequency at which the timer chip
input runs. It's also used to set the timer_rate and
timer_scale values of the qtime section of the system page.
If a variable is zero when it comes time to set the field(s)
on the system page, the library code attempts to deduce the proper
value by using one of the other frequency variables. Which one it uses
depends on the particular CPU and hardware.
- -I flag
- Enable kernel restoration as part of IFS restoration.
The flag is 0 to disable checksum verification, or 1 to enable it.
If checksum verification is enabled and fails, the entire image is reloaded.
Note:
Even if the IFS checksum verification is disabled, a checksum is still performed
on the IFS Restoration internal data structure (approximately 32 bytes) to ensure at least some data integrity.
For more information, see
Reloadable Image Filesystems
in the QNX Neutrino technotes.
- -i ifs2_size[,flags][,paddr_src][,paddr_dst]
- Enable secondary IFS restoration.
The arguments are:
- ifs2_size
- The size of the secondary IFS (note: this can be larger than the actual size).
- flags
-
- Not specified — load the secondary IFS but don't try to restore on wake-up
- R — load the secondary IFS and restore
- K or RK — load the secondary IFS and restore with a checksum
- paddr_src
-
- Not specified — the secondary IFS is located in flash after the primary IFS
- Specified — the secondary IFS is located at the physical address specified
- paddr_dst
-
- Not specified — the secondary IFS will be copied to a default location in RAM
- Specified — the secondary IFS will be copied to the physical address specified
(choose an address in a “safe” place, such as at the end of
RAM away from where the primary image is copied)
If the checksum is enabled and fails, the entire secondary IFS is reloaded.
Note:
Even if the secondary IFS checksum is disabled, a checksum is still
performed on the IFS Restoration internal data structure (approximately
16 bytes) to ensure at least some data integrity.
For more information, see
Reloadable Image Filesystems
in the QNX Neutrino technotes.
- -j addr
- For use with JTAG/hardware debuggers.
Reserve 4 bytes of RAM at the physical address
specified by addr, and copy the physical address
of the location of the system page to addr
in RAM so that it can be retrieved by a hardware debugger.
- -K channel[.channel_opts]
- Specify an output channel for kernel debugger information.
The format of this option and the default value vary from board to board.
- -N hostname
- Specify the node name. The default is the local host.
- -o hundred_loop,overhead
- Specify the calibration data (100 loop time and overhead) to store in the system page.
In order to make startup faster and reduce jitter,
nanospin_calibrate()
tries to read the calibration data from values stored in the system page.
- -P max_CPUs
- Specify the maximum number of processors to activate in a multicore system. This is useful for
testing how well your application runs on a system with fewer CPUs.
- -R size[,align[,name[,use_low_memory]]]
- Remove size memory from system use, optionally specifying the alignment and
the name of the reserved area.
This is useful for testing in a restricted-memory environment.
The size and alignment are in bytes, unless followed by one of
K (kilobytes), M (megabytes), or G (gigabytes).
You can specify more than one instance of the -R option.
If you specify the align argument, the reserved area is aligned on the boundary it specifies.
The default is 0, meaning no alignment.
If you specify the name argument, the reserved RAM area is available through the POSIX
typed memory interface under /memory/ram/name.
If you don't specify the name argument, the area is available under
/memory/ram/reserved.
The optional use_low_memory argument is an unsigned integer.
If it's zero (the default), startup gets memory from the top of memory, which doesn't work for drivers with
32-bit DMA address restrictions if the target has RAM available above 4 GB.
If use_low_memory is nonzero, startup tries to allocate from the lower end of memory,
in the hope that there's enough below4G memory to work with 32-bit DMA restrictions.
If below4G is already full, the driver can still get an address that's above 4 GB.
- -r addr,size[,flag]
- Remove size memory from system use starting at addr.
The flag is an optional argument used to specify if the memory should be cleared:
| Flag: |
Memory: |
| None |
Clears to 0 |
| 0 |
Clears to 0 |
| 1 |
Does not clear |
- -S [~]section
- Turn on (or, if you use ~section, off) output
of the specified syspage section's information.
Use this to restrict the amount of syspage information.
For more information, see the description of
print_syspage()
in the Startup Library chapter of Building Embedded Systems.
- -T
- Prevent the startup program from setting the
SYSPAGE_ENTRY(qtime)->boot_time field.
If this field is 0 the first time you call
ClockTime()
to change the time of day, the kernel sets it to the appropriate value.
This is useful if the RTC hardware isn't in UTC.
- -v[v]...
- Be verbose. More v characters cause even more verbosity.
- -Z
- Enable tickless operation.
In this mode, when the system is idle, the clock tick is “turned off” until just after
the next active timer is to fire.
For more information, see
“Clocks, timers, and power management”
in the “Understanding the Microkernel's Concept of Time” chapter of the
QNX Neutrino Programmer's Guide.
If you specify this option, the QTIME_FLAG_TICKLESS flag is set in the
qtime
member of the system page (see the System Page chapter of Building Embedded Systems).
Options for 32-bit ARM targets
The following options are supported in the startup programs for 32-bit ARM targets:
- -x
- Enable extended addressing. This lets you access physical addresses above 4 GB.
This option is only applicable on supported hardware where the CPU supports Large Physical
Address Extension (LPAE).
Options for 64-bit ARM (AArch64) startups
The following options are supported in the startup programs for 64-bit ARM (AArch64) targets:
- -E erratum, -E ~erratum
- Apply (-E erratum) or don't apply
(-E ~erratum) the workaround for the specified erratum:
Options for 32-and 64-bit x86 targets
The following options are supported in the startup programs for 32- and 64-bit x86 targets:
- -B
- By default, x86 startups use the Advanced Control and Power Interface (ACPI)
table to determine information such as the number of logical CPUs on hyperthreaded systems.
Use this option to avoid checking for ACPI in the case of buggy BIOSs;
if ACPI isn't present or you specify -B, the startup uses
the Intel Multiprocessor Specification.
- -E erratum, -E ~erratum
- Apply (-E erratum) or don't apply
(-E ~erratum) the workaround for the specified erratum:
- -x
- (32-bit x86 targets only)
Enable extended addressing.
This lets you access physical addresses above 4 GB.
This option has an effect only if the CPU supports more than 32 address lines.
On x86 CPUs, extended addressing is supported if the X86_CPU_PAE bit is on in the
SYSPAGE_ENTRY(cpuinfo)->flags.
For more information, see the
System Page
chapter of Building Embedded Systems.
- -z[z]
- Specify the source of the system clock.
By default, the startup program tries to initialize the clock from the sources in the following order, using
the first that's available:
- LAPIC (Local Advanced Programmable Interrupt Controller) timer on CPU 0
- HPET (High Precision Event Timer)
- 8254 Programmable Interval Timer
You can use the -z[z] option to affect the selection:
- -z — skip the LAPIC and HPET, and use the 8254.
- -zz — skip the LAPIC, and use the HPET if it's available, falling back
on the 8254 otherwise.
To determine which clock source was selected, do one of the following:
- Specify the -v option for the startup program; the output indicates the clock source.
- Use
pidin
to display the qtime area of the system page.
The output might look like this:
# pidin syspage=qtime
Header size=0x00000108, Total Size=0x00000cc0, #Cpu=2, Type=256
Section:qtime offset:0x00000258 size:0x00000060
boot:5b35f6a0 CPS:00000000a1ca3421 rate/scale:69841279/-15 intr:2
flags:00000002 load:14318 epoch:1970 rr_mul:0 adj count/inc:0/0
nsec:0000014dba1b3f2b stable:0000014dba1b3f2b inc:000f4233
nsec_tod_adj:153c9645d0da4000
The clock period (rate * 10scale) indicates which clock is being used.
Typical numbers are as follows:
| Clock source |
Rate |
Scale |
Period (femtoseconds) |
| LAPIC |
1 |
-8 |
10,000,000 |
| HPET |
69841279 |
-15 |
69,841,279 |
| 8259 |
838095345 |
-15 |
838,095,345 |
For more information about the contents of the system page, see the
“System Page”
chapter of Building Embedded Systems.