Binary Interface - s-ol/HowDoIOS GitHub Wiki
This entry is deprecated! whilst most of it will still be right after I am done with Drivers, some of it will change. Be advised.
All Applications and drivers that have to be loaded after boot time have to confirm to this standard (until some other binary interface is supported).
| field | size | notes |
|---|---|---|
| magic number | 1w | 0x4110. magic number that makes the file recognizable as an executable. |
| header version | 1w | MMMMMMMMmmmmmmmm: Major, minor. This version is 1.0, represented as 0x0100 |
| header size | 1w | full header size |
| code + data size | 1w | full file size, including all pre-allocated memory |
| flags | 1w | 111111111111111s Semaphore-like: only one process may use the exports at a time |
| entry point | 1w | entry point for executable relative to start of code section, default 0 0xffff for export-only binaries |
| relocation table | 1..Nw | see below |
| exports table | 1..Nw | see below |
| imports table | 1..Nw | see below |
The code relocation table is a list of fixups. Every label you use should be on this list. Note that short literals are not supported.
| field | size | notes |
|---|---|---|
| num fixups | 1w | number of entries (or 0) |
| fixup address | 0..Nw | word that should be fixed. Fixing is done by adding the binary's offset from 0x0000 to this word |
Export tables are used to give other processess the ability to interact with the spawned process via Interfaces (see Driver for more info). All routines in this table must confirm too the Calling Convention
| field | size | notes |
|---|---|---|
| num entries | 1w | number of entries |
| interfaces | 0..Nw | ids of the interfaces implemented, ommited if num entries is 0
|
| interface exports | 0..Nw | exports of each interface, ommited if num entries is 0
|
Interface Exports:
| field | size | notes |
|---|---|---|
| num entries | 1w | number of entries for corresponding interface; 0 if interface is virtual |
| routine address | 0-Nw | word that should be jumped too |
The imports table describes what requirements have to be met to be able to execute the process. This usually includes interfaces like the FILESYSTEM driver or HARDWARE virtual interface.
| field | size | notes |
|---|---|---|
| num entries | 1w | number of entries; 0 if "dependency-less" |
| interfaces | 0..Nw | ids of the interfaces implemented, ommited if num entries is 0
|