Specifications

• ioctl()
• isatty()
• kill()
• lseek()
• open()
• read()
• sbrk()
• settimeofday()
• stat()
• usleep()
• wait()
• write()
The most commonly used functions are those that relate to file I/O.
For more information, refer to the “File System” chapter.
For more information about the use of these functions, refer to the "HAL API Reference" chapter.
Related Information
• File System on page 6-5
• HAL API Reference on page 14-1
File System
The HAL provides infrastructure for UNIX-style file access. You can use this infrastructure to build a file
system on any storage devices available in your hardware.
For more information, refer to an example in the "Read-Only Zip File System" chapter.
You can access files in a HAL-based file system by using either the C standard library file I/O functions in
the newlib C library (for example fopen(), fclose(), and fread()), or using the UNIX-style file I/O
provided by the HAL.
The HAL provides the following UNIX-style functions for file manipulation:
• close()
• fstat()
• ioctl()
• isatty()
• lseek()
• open()
• read()
• stat()
• write()
For more information about these functions, refer to the "HAL API Reference" chapter.
The HAL registers a file subsystem as a mount point in the global HAL file system. Attempts to access files
below that mount point are directed to the file subsystem. For example, if a read-only zip file subsystem
(zipfs) is mounted as /mount/zipfs0, the zipfs file subsystem handles calls to fopen() for /mount/zipfs0/
myfile.
There is no concept of a current directory. Software must access all files using absolute paths.
NII5V2
2015.05.14
File System
6-5
Developing Programs Using the Hardware Abstraction Layer
Altera Corporation
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