start.S currently cannot be compiled with Clang 16 and binutils 2.40:
ld: start.o(.text+0x8): misaligned symbol `__bss_start' (0xc1e5) for
relocation R_390_PC32DBL
According to the built-in linker script of ld, the symbol __bss_start
can actually point *before* the .bss section and does not need to have
any alignment, so in certain situations (like when using the internal
assembler of Clang), the __bss_start symbol can indeed be unaligned
and thus it is not suitable for being used with the "larl" instruction
that needs an address that is at least aligned to halfwords.
The problem went unnoticed so far since binutils <= 2.39 did not
check the alignment, but starting with binutils 2.40, such unaligned
addresses are now refused.
Fix it by loading the address indirectly instead.
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2216662
Reported-by: Miroslav Rezanina <mrezanin@redhat.com>
Suggested-by: Andreas Krebbel <andreas.krebbel@de.ibm.com>
Message-Id: <20230629104821.194859-8-thuth@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
The stack array is only referenced from the start-up code (which is
shared between the s390-ccw.img and the s390-netboot.img), but it is
currently declared twice, once in main.c and once in netmain.c.
It makes more sense to declare this in start.S instead - which will
also be helpful in the next patch, since we need to mention the .bss
section in start.S in that patch.
While we're at it, let's also drop the huge alignment of the stack,
since there is no technical requirement for aligning it to page
boundaries.
Message-Id: <20230627074703.99608-4-thuth@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Providing the space of a stack frame is the duty of the caller,
so we should reserve 160 bytes before jumping into the main function.
Otherwise the main() function might write past the stack array.
While we're at it, add a proper STACK_SIZE macro for the stack size
instead of using magic numbers (this is also required for the following
patch).
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Message-Id: <20230627074703.99608-3-thuth@redhat.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
start.S is currently indented with a mixture of spaces and tabs, which
is quite ugly. QEMU coding style says indentation should be 4 spaces,
and this is also what we are using in the assembler files in the
tests/tcg/s390x/ folder already, so let's adjust start.S accordingly.
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Message-Id: <20230627074703.99608-2-thuth@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Fix typos (discovered with the 'codespell' utility).
Note: Though "migrateable" still seems to be a valid spelling, we change
it to "migratable" since this is the way more common spelling here.
Message-Id: <20221111182828.282251-1-thuth@redhat.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Let's setup a PGM PSW, so we won't load 0s when a program exception
happens. Instead we'll load a disabled wait PSW.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20201006094249.50640-5-frankja@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
panic() was defined for the ccw and net bios, i.e. twice, so it's
cleaner to rather put it into the header.
Also let's add an infinite loop into the assembly of disabled_wait() so
the caller doesn't need to take care of it.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20200624075226.92728-9-frankja@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Introduce a library function for executing format-0 and format-1
channel programs and waiting for their completion before continuing
execution.
Add cu_type() to channel io library. This will be used to query control
unit type which is used to determine if we are booting a virtio device or a
real dasd device.
Signed-off-by: Jason J. Herne <jjherne@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Message-Id: <1554388475-18329-9-git-send-email-jjherne@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
When compiling the s390-ccw firmware with Clang 7.0.1, I get the
following errors:
pc-bios/s390-ccw/start.S:62:19: error: invalid use of length addressing
stctg 0,0,0(15)
^
pc-bios/s390-ccw/start.S:63:12: error: invalid use of length addressing
oi 6(15), 0x2
^
pc-bios/s390-ccw/start.S:64:19: error: invalid use of length addressing
lctlg 0,0,0(15)
^
pc-bios/s390-ccw/start.S:76:19: error: invalid use of length addressing
stctg 0,0,0(15)
^
pc-bios/s390-ccw/start.S:77:12: error: invalid use of length addressing
ni 6(15), 0xfd
^
pc-bios/s390-ccw/start.S:78:19: error: invalid use of length addressing
lctlg 0,0,0(15)
^
pc-bios/s390-ccw/start.S:79:12: error: invalid operand for instruction
br 14
^
Let's use proper register names like in the rest of this file to fix it.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1547123559-30476-1-git-send-email-thuth@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
The QEMU ELF loader does not zero the bss segment.
This resulted in several bugs, e.g. see
commit 5d739a4787 (s390-ccw.img: Fix sporadic errors with ccw boot image - initialize css)
commit 6a40fa2669d3 (s390-ccw.img: Initialize next_idx)
commit 8775d91a0f (pc-bios/s390-ccw: Fix problem with invalid virtio-scsi LUN when rebooting)
Let's fix this once and forever by letting the BIOS zero the bss itself.
Suggested-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <20171122142627.73170-3-borntraeger@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
To IPL from a device, pc-bios receives from qemu a device address via
general register 7. The better way to do it is to use diag308/6
instruction which returns so called
"IplParameterBlock". IplParameterBlock contains the device address for
IPL and additional parameters that can be used by pc-bios.
This patch allows pc-bios to get device address via diag308/6 and
doesn't use gr7 passed boot information anymore.
Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
We have to consume the outstanding service interrupt after each
service call, otherwise a correct implementation will return
CC=2 on subsequent service calls.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Use the passed device, if there is no device, use the first applicable device.
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
dont waste cpu power on an error condition. Lets stop the guest
with a disabled wait.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
We want to write most of our code in C, so add a small assembly
stub that jumps straight into C code for us to continue booting.
Signed-off-by: Alexander Graf <agraf@suse.de>
