mirror of
https://github.com/encounter/ph.git
synced 2026-03-30 11:34:37 -07:00
Aetias
44 lines
1.4 KiB
Markdown
44 lines
1.4 KiB
Markdown
# Inline assembler
|
|
- [Differences from standalone assembler](#differences-from-standalone-assembler)
|
|
|
|
## Differences from standalone assembler
|
|
Below is a list of differences between the inline assembler and the standalone disassembler. If something is missing, feel free
|
|
to contribute to the list!
|
|
- [Pool constants](#pool-constants)
|
|
- [Data sections](#data-sections)
|
|
- [Comments](#comments)
|
|
|
|
### Pool constants
|
|
There is no `.word` or other data directives in the inline assembler. Instead, there are three built-in instructions you can
|
|
use:
|
|
|
|
#### `dcd`: Emits a literal 32-bit value
|
|
```asm
|
|
mov r0, [pc, #0]
|
|
bx lr
|
|
dcd 0x1234
|
|
```
|
|
|
|
#### `ldconst`: Loads a literal 32-bit value
|
|
```asm
|
|
ldconst r0, #0x1234
|
|
bx lr
|
|
```
|
|
This code is equivalent to the above example using `dcd`.
|
|
|
|
#### `lda`: Loads the address to a symbol
|
|
```
|
|
lda r0, data_ov00_02abcdef
|
|
```
|
|
|
|
### Data sections
|
|
Directives such as `.section`, `.data` and `.bss` are not supported in the inline assembler. It's possible to change section
|
|
with a `#pragma`, but there's no need to. Data should only be defined in standalone assembly or C/C++.
|
|
|
|
### Comments
|
|
Inline assembly is handled by the compiler, so comments must be in C/C++ format. This means using `//` and `/* */` instead of
|
|
`#` or `;`.
|
|
|
|
Semicolons `;` instead mark the end of an instruction and are optional. You can use them to put multiple instructions on one
|
|
line, but we avoid doing it so that we can preserve as much similarity to standalone assembly as possible.
|