aboutsummaryrefslogtreecommitdiff
path: root/pc-bios/s390-ccw/start.S
AgeCommit message (Collapse)Author
2023-06-29pc-bios/s390-ccw: Don't use __bss_start with the "larl" instructionThomas Huth
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>
2023-06-29pc-bios/s390-ccw: Move the stack array into start.SThomas Huth
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>
2023-06-29pc-bios/s390-ccw: Provide space for initial stack frame in start.SThomas Huth
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>
2023-06-29pc-bios/s390-ccw: Fix indentation in start.SThomas Huth
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>
2022-11-16s390x: Fix spelling errorsThomas Huth
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>
2020-10-06pc-bios: s390x: Go into disabled wait when encountering a PGM exceptionJanosch Frank
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>
2020-07-02pc-bios: s390x: Move panic() into header and add infinite loopJanosch Frank
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>
2019-04-12s390-bios: Support for running format-0/1 channel programsJason J. Herne
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>
2019-01-18pc-bios/s390-ccw: Use proper register names for ClangThomas Huth
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>
2017-12-14pc-bios/s390-ccw: zero out bss sectionChristian Borntraeger
The QEMU ELF loader does not zero the bss segment. This resulted in several bugs, e.g. see commit 5d739a4787a5 (s390-ccw.img: Fix sporadic errors with ccw boot image - initialize css) commit 6a40fa2669d3 (s390-ccw.img: Initialize next_idx) commit 8775d91a0f42 (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>
2016-05-17pc-bios/s390-ccw: Get device address via diag 308/6Alexander Yarygin
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>
2015-06-30s390-ccw.img: Consume service interruptsChristian Borntraeger
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>
2013-05-06S390: BIOS boot from given deviceDominik Dingel
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>
2013-04-26s390-ccw.img: replace while loop with a disabled wait on s390 biosChristian Borntraeger
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>
2013-04-26S390: ccw firmware: Add start assemblyAlexander Graf
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>