On 27/08/2020 11.31, Janosch Frank wrote:
> Currently we always overwrite the mentioned exception new PSWs before
> loading the enabled wait PSW. Let's save the PSW before overwriting
> and restore it right before starting the loaded kernel.
>
> Signed-off-by: Janosch Frank <[email protected]>
> ---
>
> Maybe we should rather statically allocate a lowcore so we don't dirty
> 0x0 at all.
>
> ---
> pc-bios/s390-ccw/jump2ipl.c | 3 ++
> pc-bios/s390-ccw/start.S | 62 +++++++++++++++++++++++++++----------
> 2 files changed, 48 insertions(+), 17 deletions(-)
>
> diff --git a/pc-bios/s390-ccw/jump2ipl.c b/pc-bios/s390-ccw/jump2ipl.c
> index 143d027bf7..a44f3ab5b3 100644
> --- a/pc-bios/s390-ccw/jump2ipl.c
> +++ b/pc-bios/s390-ccw/jump2ipl.c
> @@ -13,12 +13,15 @@
> #define KERN_IMAGE_START 0x010000UL
> #define RESET_PSW_MASK (PSW_MASK_SHORTPSW | PSW_MASK_64)
>
> +extern uint64_t *psw_save_io, *psw_save_ext;
I think that should be
extern uint64_t psw_save_io[], psw_save_ext[];
instead ... otherwise you'll end up with some funny bugs here, won't you?
> uint64_t *reset_psw = 0, save_psw, ipl_continue;
>
> static void jump_to_IPL_2(void)
> {
> /* Restore reset PSW and io and external new PSWs */
Ok, now the comment makes sense :-)
> *reset_psw = save_psw;
> + memcpy((void *)0x1f0, psw_save_io, 16);
> + memcpy((void *)0x1b0, psw_save_ext, 16);
Could you use &lowcore->external_new_psw and &lowcore->io_new_psw
instead of the magic numbers?
Thomas
