Specifications

Related Information
• Developing Device Drivers for the Hardware Abstraction Layer
For more information about developing device drivers.
• Developing Device Drivers for the Hardware Abstraction Layer
For more information about developing device drivers.
• Nios II Software Build Tools on page 4-1
For more information about specifying file paths with the Nios II SBT, refer to "Nios II Embedded
Software Projects".
Thread-Safe HAL Drivers
To enable a driver to be ported between the HAL and MicroC/OS-II environments, Altera defines a set of
operating system-independent macros that provide access to operating system facilities. These macros
implement functionality that is only relevant to a multi-threaded environment. When compiled for a
MicroC/OS-II project, the macros expand to MicroC/OS-II API calls. When compiled for a single-
threaded HAL project, the macros expand to benign empty implementations. These macros are used in
Altera-provided device driver code, and you can use them if you need to write a device driver with similar
portability.
For more information about the functionality in the MicroC/OS-II environment, refer to MicroC/OS-II:
The Real-Time Kernel.
The path listed for the header file is relative to the <Nios II EDS install path>/components/micrium_uc_osii/
UCOSII/inc directory.
Table 10-1: OS-Independent Macros for Thread-Safe HAL Drivers
Macro Defined in
Header
MicroC/OS-II Implementation Single-Threaded
HAL Implementa‐
tion
ALT_FLAG_GRP(group) os/alt_flag.h Create a pointer to a flag group
with the name group.
Empty
statement
ALT_EXTERN_FLAG_
GRP(group)
os/alt_flag.h Create an external reference to a
pointer to a flag group with name
group.
Empty
statement
ALT_STATIC_FLAG_
GRP(group)
os/alt_flag.h Create a static pointer to a flag
group with the name group.
Empty
statement
ALT_FLAG_CREATE(group,
flags)
os/alt_flag.h Call OSFlagCreate() to initialize
the flag group pointer, group, with
the flags value flags. The error
code is the return value of the
macro.
Return 0
(success)
ALT_FLAG_PEND(group,
flags, wait_type,
timeout)
os/alt_flag.h Call OSFlagPend() with the first
four input arguments set to group,
flags, wait_type, and timeout
respectively. The error code is the
return value of the macro.
Return 0
(success)
10-4
Thread-Safe HAL Drivers
NII5V2
2015.05.14
Altera Corporation
MicroC/OS-II Real-Time Operating System
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