747295f1a8
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@62 42af7a65-404d-4744-a932-0658087f49c3
252 lines
8.6 KiB
Plaintext
252 lines
8.6 KiB
Plaintext
Architecture-Specific Code
|
|
^^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
Table of Contents
|
|
^^^^^^^^^^^^^^^^^
|
|
|
|
o Architecture-Specific Code
|
|
o Summary of Files
|
|
o Supported Architectures
|
|
o Configuring NuttX
|
|
|
|
Architecture-Specific Code
|
|
^^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
The file include/nuttx/arch.h identifies all of the APIs that must
|
|
be provided by the architecture specific logic. (It also includes
|
|
arch/<arch-name>/arch.h as described below).
|
|
|
|
Directory Structure
|
|
^^^^^^^^^^^^^^^^^^^
|
|
|
|
Thie arch directory contains architecture specific logic. Each aructure
|
|
provide a a subdirectory <arch-name>under arch/ with the folling characteristics:
|
|
|
|
|
|
<arch-name>
|
|
|-- Make.defs
|
|
|-- defconfig
|
|
|-- setenv.sh
|
|
|-- include
|
|
| |-- arch.h
|
|
| |-- irq.h
|
|
| `-- types.h
|
|
`-- src
|
|
|-- Makefile
|
|
`-- (architecture-specific source files)
|
|
|
|
Summary of Files
|
|
^^^^^^^^^^^^^^^^
|
|
|
|
Make.defs -- This makefile fragment provides architecture and
|
|
tool-specific build options. It will be included by all other
|
|
makefiles in the build (once it is installed). This make fragment
|
|
should define:
|
|
|
|
Tools: CC, LD, AR, NM, OBJCOPY, OBJDUMP
|
|
Tool options: CFLAGS, LDFLAGS
|
|
|
|
When this makefile fragment runs, it will be passed TOPDIR which
|
|
is the path to the root directory of the build. This makefile
|
|
fragment may include ${TOPDIR}/.config to perform configuration
|
|
specific settings. For example, the CFLAGS will most likely be
|
|
different if CONFIG_DEBUG=y.
|
|
|
|
defconfig -- This is a configuration file similar to the Linux
|
|
configuration file. In contains varialble/value pairs like:
|
|
|
|
CONFIG_VARIABLE=value
|
|
|
|
This configuration file will be used at build time:
|
|
|
|
(1) as a makefile fragment included in other makefiles, and
|
|
(2) to generate include/nuttx/config.h which is included by
|
|
most C files in the system.
|
|
|
|
The following variables are recognized by the build (you may
|
|
also include architecture-specific settings).
|
|
|
|
Architecture selection:
|
|
|
|
CONFIG_ARCH - identifies the arch subdirectory
|
|
CONFIG_ARCH_name - for use in C code
|
|
|
|
General OS setup
|
|
|
|
CONFIG_EXAMPLE - identifies the subdirectory in examples
|
|
that will be used in the build
|
|
CONFIG_DEBUG - enables built-in debug options
|
|
CONFIG_DEBUG_VERBOSE - enables verbose debug output
|
|
CONFIG_HAVE_LOWPUTC - architecture supports low-level, boot
|
|
time console output
|
|
CONFIG_MM_REGIONS - If the architecture includes multiple
|
|
regions of memory to allocate from, this specifies the
|
|
number of memory regions that the memory manager must
|
|
handle and enables the API mm_addregion(start, end);
|
|
CONFIG_RR_INTERVAL - The round robin timeslice will be set
|
|
this number of milliseconds; Round robin scheduling can
|
|
be disabled by setting this value to zero.
|
|
CONFIG_SCHED_INSTRUMENTATION - enables instrumentation in
|
|
scheduler to monitor system performance
|
|
CONFIG_TASK_NAME_SIZE - Spcifies that maximum size of a
|
|
task name to save in the TCB. Useful if scheduler
|
|
instrumentation is selected. Set to zero to disable.
|
|
CONFIG_START_YEAR, CONFIG_START_MONTH, CONFIG_START_DAY -
|
|
Used to initialize the internal time logic.
|
|
CONFIG_JULIAN_TIME - Enables Julian time conversions
|
|
CONFIG_DEV_CONSOLE - Set if architecture-specific logic
|
|
provides /dev/console. Enables stdout, stderr, stdin.
|
|
|
|
The following can be used to disable categories of APIs supported
|
|
by the OS. If the compiler supports weak functions, then it
|
|
should not be necessary to disable functions unless you want to
|
|
restrict usage of those APIs.
|
|
|
|
There are certain dependency relationships in these features.
|
|
|
|
o mq_notify logic depends on signals to awaken tasks
|
|
waiting for queues to become full or empty.
|
|
o pthread_condtimedwait() depends on signals to wake
|
|
up waiting tasks.
|
|
|
|
CONFIG_DISABLE_CLOCK, CONFIG_DISABLE_PTHREAD.
|
|
CONFIG_DISABLE_SIGNALS, CONFIG_DISABLE_MQUEUE
|
|
|
|
|
|
Misc libc settings
|
|
|
|
CONFIG_NOPRINTF_FIELDWIDTH - sprintf-related logic is a
|
|
little smaller if we do not support fieldwidthes
|
|
|
|
Allow for architecture optimized implementations
|
|
|
|
The architecture can provide optimized versions of the
|
|
following to improve sysem performance
|
|
|
|
CONFIG_ARCH_MEMCPY, CONFIG_ARCH_MEMCMP, CONFIG_ARCH_MEMMOVE
|
|
CONFIG_ARCH_MEMSET, CONFIG_ARCH_STRCMP, CONFIG_ARCH_STRCPY
|
|
CONFIG_ARCH_STRNCPY, CONFIG_ARCH_STRLEN, CONFIG_ARCH_BZERO
|
|
CONFIG_ARCH_KMALLOC, CONFIG_ARCH_KZMALLOC, CONFIG_ARCH_KFREE
|
|
|
|
Sizes of configurable things (0 disables)
|
|
|
|
CONFIG_MAX_TASKS - The maximum number of simultaneously
|
|
active tasks. This value must be a power of two.
|
|
CONFIG_NPTHREAD_KEYS - The number of items of thread-
|
|
specific data that can be retained
|
|
CONFIG_NFILE_DESCRIPTORS - The maximum number of file
|
|
descriptors (one for each open)
|
|
CONFIG_NFILE_STREAMS - The maximum number of streams that
|
|
can be fopen'ed
|
|
CONFIG_NAME_MAX - The maximum size of a file name.
|
|
CONFIG_STDIO_BUFFER_SIZE - Size of the buffer to allocate
|
|
on fopen. (Only if CONFIG_NFILE_STREAMS > 0)
|
|
CONFIG_NUNGET_CHARS - Number of characters that can be
|
|
buffered by ungetc() (Only if CONFIG_NFILE_STREAMS > 0)
|
|
CONFIG_PREALLOC_MQ_MSGS - The number of pre-allocated message
|
|
structures. The system manages a pool of preallocated
|
|
message structures to minimize dynamic allocations
|
|
CONFIG_MQ_MAXMSGSIZE - Message structures are allocated with
|
|
a fixed payload size given by this settin (does not include
|
|
other message structure overhead.
|
|
CONFIG_PREALLOC_WDOGS - The number of pre-allocated watchdog
|
|
structures. The system manages a pool of preallocated
|
|
watchdog structures to minimize dynamic allocations
|
|
|
|
Stack and heap information
|
|
|
|
CONFIG_BOOT_FROM_FLASH - Some configurations support XIP
|
|
operation from FLASH.
|
|
CONFIG_STACK_POINTER - The initial stack pointer
|
|
CONFIG_PROC_STACK_SIZE - The size of the initial stack
|
|
CONFIG_PTHREAD_STACK_MIN - Minimum pthread stack size
|
|
CONFIG_PTHREAD_STACK_DEFAULT - Default pthread stack size
|
|
CONFIG_HEAP_BASE - The beginning of the heap
|
|
CONFIG_HEAP_SIZE - The size of the heap
|
|
|
|
setenv.sh -- This is a script that you can include that will be installed at
|
|
the toplevel of the directory structure and can be sourced to set any
|
|
necessary environment variables.
|
|
|
|
include/arch.h
|
|
This is a hook for any architecture specific definitions that may
|
|
be needed by the system. It is included by include/nuttx/arch.h
|
|
|
|
include/types.h
|
|
This provides architecture/toolchain-specific definitions for
|
|
standard types. This file should typedef:
|
|
|
|
sbyte, ubyte, uint8, boolean, sint16, uint16, sint32, uint32
|
|
|
|
and
|
|
|
|
sint64, uint64
|
|
|
|
if the architecture supports 64-bit integers.
|
|
|
|
irqstate_t
|
|
|
|
Must be defined to the be the size required to hold the interrupt
|
|
enable/disable state.
|
|
|
|
This file will be included by include/sys/types.h and be made
|
|
available to all files.
|
|
|
|
include/irq.h
|
|
This file needs to define some architecture specific functions (usually
|
|
inline if the compiler supports inlining) and structure. These include:
|
|
|
|
- struct xcptcontext. This structures represents the saved context
|
|
of a thread.
|
|
|
|
- irqstate_t irqsave(void) -- Used to disable all interrupts.
|
|
|
|
- void irqrestore(irqstate_t flags) -- Used to restore interrupt
|
|
enables to the same state as before irqsave was called.
|
|
|
|
This file must also define NR_IRQS, the total number of IRQs supported
|
|
by the board.
|
|
|
|
src/Makefile
|
|
This makefile will be executed to build the targets src/libup.a and
|
|
src/up_head.o. The up_head.o file holds the entry point into the system
|
|
(power-on reset entry point, for example). It will be used in
|
|
the final link with libup.a and other system archives to generate the
|
|
final executable.
|
|
|
|
Supported Architectures
|
|
^^^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
arch/c5471
|
|
TI TMS320C5471 (also called TMS320DM180).
|
|
NuttX operates on the ARM7 of this dual core processor. This port
|
|
uses the Spectrum Digital evaluation board with a GNU arm-elf toolchain*.
|
|
This port is in progress and partially functional (However, my board
|
|
is dead at the moment so it will be awhile before I fix it).
|
|
|
|
arch/pjrc-8051
|
|
8051 Microcontroller. This port uses the PJRC 87C52 development system
|
|
and the SDCC toolchain. This port is not quite ready for prime time.
|
|
|
|
arch/sim
|
|
x86 Linux Simulation</b>. Fully functional.
|
|
|
|
Other ports for the for the TI TMS320DM270 and for MIPS are in various states
|
|
of progress
|
|
|
|
Configuring NuttX
|
|
^^^^^^^^^^^^^^^^^
|
|
|
|
Configuring NuttX requires only copying
|
|
|
|
arch/<arch-name>/Make.def to ${TOPDIR}/Make.defs
|
|
arch/<arch-name>/setenv.sh to ${TOPDIR}/setenv.sh
|
|
arch/<arch-name>/defconfig to ${TOPDIR}/.config
|
|
|
|
There is a script that automates these steps. The following steps will
|
|
accomplish the same configuration:
|
|
|
|
cd tools
|
|
./configure.sh <arch-name>
|
|
|
|
|