Re: [Qemu-devel] [PATCH] roms: Flush icache when writing roms to guest memory

[address@hidden]

> On 11.12.2013, at 16:15, Alexander Graf < address@hidden > wrote:
>
> Well, this really is a simplified view of the world.
> 
> On real hardware the system boots up with caches disabled. Firmware is
> then responsible for enabling caches and flushing things as it goes.
> Firmware loads the kernel into ram, flushing the icache on those regions
> it wrote to along the way. The kernel boots and every time it faults in a
> page, it flushes caches for that page.
> 
> So really the problem is that we're skipping the "cache disabled
> firmware" step. With this patch, we're simulating a bootloader's behavior
> when writing a blob into guest memory. Since that's really what we are
> trying to behave like - a bootloader.

The cache synchronization is required by self-modifying code not just 
bootloaders.

-Mike