On Tue, 17 Dec 2019 16:06:42 +0100 Thomas Huth <[email protected]> wrote:
> There are currently two bugs in s390x_code[]: First, the initial jump > uses the wrong offset, so it was jumping to 0x1014 instead of 0x1010. > Second, LHI only loads the lower 32-bit of the register. > > Everything worked fine as long as the s390-ccw bios code was jumping > here with r3 containing zeroes in the uppermost 48 bit - which just > happened to be the case so far by accident. But we can not rely on this > fact, and indeed one of the recent suggested patches to jump2ipl.c cause > the newer GCCs to put different values into r3. In that case the code > from s390x_code[] crashes very ungracefully. > > Thus let's make sure to jump to the right instruction, and use LGHI > instead of LHI to make sure that we always zero out the upper bits > of the register. > > Signed-off-by: Thomas Huth <[email protected]> > --- > tests/boot-sector.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) Thanks, applied.
