can i copy compiled asm instructions and jump to it

[anthony]

in an os could i theoretically copy hexadecimal code of compiled assembly into a space in memory and jump to it

kinda like this

Code: Select all

 ┌────────────┐     jump
 │App Executer├─────────────────────┐
 └────────────┘                     │
                                   │
                                   │
                                   │
                                   │
                                   │
                                   ▼
┌────────────────┐   copy   ┌─────────────┐
│Hexadecimal Code├─────────►│Space for App│
└────────────────┘          └─────────────┘

i thought about it at like 4am when trying to sleep so it probably wont work or only sounds good in theory

[Octocontrabass]

Isn't that how all programs get loaded?

[anthony]

Isn't that how all programs get loaded?

oh

[anthony]

so what i did was just have a function which copies a 128-member u16 array to an address (0x4000) and just uses inline assembly to jump into it and it works when copying an array with assembly of just cli hlt

[iansjack]

Just make sure that any memory references in the code are relative, not absolute.

[iansjack]

Isn't that how all programs get loaded?

Not really. Many program loaders also perform some relocation of memory addresses. Simply copying hex codes places some restrictions on the code being copied.

[davmac314]

in an os could i theoretically copy hexadecimal code of compiled assembly into a space in memory and jump to it

I think you mean "data representing compiled assembly". It's not hexadecimal nor any other base; it's just data. Don't use "hexadecimal" to mean "data"