Re: [Qemu-devel] [PATCH v3 3/7] hw/arm: make bitbanded IO optional on ARM M Profile
On 25 July 2018 at 09:59, Stefan Hajnoczi wrote: > Some ARM CPUs have bitbanded IO, a memory region that allows convenient > bit access via 32-bit memory loads/stores. This eliminates the need for > read-modify-update instruction sequences. > > This patch makes this optional feature a ARMMProfile qdev property, > allowing boards to choose whether they want bitbanding or not. > > Status of boards: > * iotkit (Cortex M33), no bitband > * mps2 (Cortex M3), bitband > * msf2 (Cortex M3), bitband > * stellaris (Cortex M3), bitband > * stm32f205 (Cortex M3), bitband > > Signed-off-by: Stefan Hajnoczi Reviewed-by: Peter Maydell thanks -- PMM
Re: [Qemu-devel] [PATCH v3 3/7] hw/arm: make bitbanded IO optional on ARM M Profile
On 25 July 2018 at 09:59, Stefan Hajnoczi wrote: > Some ARM CPUs have bitbanded IO, a memory region that allows convenient > bit access via 32-bit memory loads/stores. This eliminates the need for > read-modify-update instruction sequences. > > This patch makes this optional feature a ARMMProfile qdev property, > allowing boards to choose whether they want bitbanding or not. > > Status of boards: > * iotkit (Cortex M33), no bitband > * mps2 (Cortex M3), bitband > * msf2 (Cortex M3), bitband > * stellaris (Cortex M3), bitband > * stm32f205 (Cortex M3), bitband > > Signed-off-by: Stefan Hajnoczi This fixes a bug in the MPS2 boards, incidentally, where the Ethernet controller is inaccessible because it's hidden by the shouldn't-be-present bitbanding region... thanks -- PMM
