unix - Homebrew UNIX operating system

Age	Commit message (Collapse)	Author
2018-08-01	Defined EOF as -1 in stdio.h.	Jake Mannens
	Implemented the sprintf() library function in lib/stdio.c which uses the vsprintf() function. Implemented a very primative controlling TTY for each process. This is achieved by a switch in the sys_puts system call which uses the 'ctty' element of the process' task structure to determine an appropriate I/O channel. A negative ctty value doesn't equate to any I/O channel effectively disabling the process' output. Added the sys_ctty system call which allows a process to set it's own ctty value. Removed the sys_rsputs system call. Output to serial is now performed by the process first setting it's ctty value to 1, then invoking sys_puts.
2018-07-25	Added missing prototype for puts() in stdio.h.	Jake Mannens
	Implemented a basic serial interface using COM0 which can be accessed with the system call sys_puts as well as the library functions rsputs() and rsprintf(). Renamed puts() in con.c to con_puts() and made the function static to avoid interference with the library function puts().
2018-07-08	Added a printf() function to the library under stdio.c which uses the	Jake Mannens
	vsprintf() function to render formatted strings and then the puts system call to output them. Moved the vsprintf() function from the kernel to the library. Furthermore, the prototype for the function has been moved from the kernel's headers, to the new header file stdio.h. Renamed the kernel's internal printf() function to printk() in order to avoid confusion with the library provided function. Renamed the sys_print system call to the more appropriate name, sys_puts. Added a new system call sys_time, which returns the system's uptime in seconds. This is mainly for testing the userspace binary and will not be permanent. Added the file time.c to the library which contains the caller for sys_time and a helper routine sleep() which delays execution for the specified number of seconds. The new header file time.h contains prototypes for both these functions as well as the definition for the type time_t. Fixed a bug in which the value of EAX was not properly passed to the system call handler, resulting in the wrong system call being executed. This was caused by the code in the SAVE macro not properly preserving the value. Fixed a bug in which the value of EAX was not preserved during a return from system call, but rather restored with the original EAX value prior to the call. As a result, system call return codes were not properly passed. This has been corrected by introducing a new macro RESTORE_SYS which carries out the same restore operations, but maintains EAX prior to the return.