# Re: \[RFC/PATCH 1/3\] powerpc: add ioremap\_bat() function for setting up BAT translated IO regions.

- From: Kumar Gala \<hidden\>
- Date: 2008-08-06 14:17:07 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2008/08/9444233
- Thread: https://ratatoskr.run/linuxppc-dev/2008/08/9444193/t.md

```text

On Aug 6, 2008, at 1:02 AM, Grant Likely wrote:

> From: Grant Likely <redacted>
>
> ioremap_bat() is useful for things like mapping SoC internally memory mapped
> register and early text because it allows mappings to devices to be setup
> early in the boot process where they are needed, and the mappings persist
> after the MMU is configured.
>
> Without ioremap_bat(), setting up the MMU would cause the early text
> mappings to get lost and mostly likely result in a kernel panic on the next
> attempt at output.
>
> Signed-off-by: Grant Likely <redacted>
> ---

why can't we just do this in ioremap itself?

- k
```