Anonymous user
COM: Difference between revisions
Jump to navigation
Jump to search
COM files are able to do their own memory organisation on the 8086 - the 64kB limit only applies to code that can't or doesn't make use of segmentation.
| [unchecked revision] | [unchecked revision] |
m (Added a small amount of information and made nicer to read.) |
(COM files are able to do their own memory organisation on the 8086 - the 64kB limit only applies to code that can't or doesn't make use of segmentation.) |
||
Line 6:
COM files are extremely simple executable files. They are useful for loading programs without complications like relocating symbols, reading file headers, etc. However, their simplicity can make their usefulness limited, so you may want to support something more complex but useful, like [[ELF]], once your OS is advanced.
COM files were used by MS-DOS. They are raw binaries, meaning there is no header data
MS-DOS creates and stores an info structure starting at offset 0 and ending just before 0x100, called the Program Segment Prefix (PSP).
COM files usually terminate with a RET instruction. On
===Loading===
| |||