The location of the handler at offset 0x20 from the start of memory,
immediately after the 32-byte reset vector, matches the expectations
of real hardware (e.g., a 3c120 board).
Author: Sandra Loosemore <sandra@codesourcery.com>
Date: Wed Mar 13 20:22:16 2019 -0700
Add semihosting documentation for nios2 and m68k.
QEMU maintainers have asked for a specification of the nios2
semihosting interface. Since it's essentially a copy of the m68k
implementation, this patch adds a document for that target as well.
The M class cores don't support Semihosting v2 mixed mode, but we were
accidentally using the new immediates for it. My last patch changed the
immediates which broke the build because doing a full multi-lib build
including M architectures now results in an assembler error instead of
silently doing the wrong thing.
This fixes the issue by changing the defines around such that According
to the specs any M class build uses the normal semihosting instructions.
Regtested on arm-none-eabi and no issues, using a build with m class
multilibs too.
The Semihosting v2 protocol requires us to output the Armv8-a HLT instruction
when in mixed mode (SEMIHOST_V2_MIXED_MODE), however it also requires this to
be done for Armv7-a and earlier architectures.
The HLT instruction is defined in the undefined encoding space for older
architectures but simulators such as QEMU already trap on it [1] for all
architectures and is a requirement for semihosting v2 [2].
Unfortunately the GAS restricts the use of HLT to Armv8-a which requires us to
use the instruction encodings we want directly in crt0.
This patch does this, I have not updated newlib/libc/* as that is quite out of
date already. A proper sync is needed in order to get things back in sync.
A different patch for this would be best.
[1] 19a6e31c9d
[2] https://developer.arm.com/docs/100863/latest/the-semihosting-interface
The toplevel makefile used by binutils/gcc/newlib/etc has install-pdf and
install-html targets, but they fail because libgloss doesn't support them.
Tested with an arm-eabi combined tree build and install, and verifying that
the install-pdf and install-html targets now work, and that the pdf and html
doc files are now in the install tree.
libgloss/
* Makefile.in (install-html, install-pdf): New.
* doc/Makefile.in (htmldir, pdfdir): New.
(porting.ps): Delete white space on blank line.
(install-pdf, install-html): New.
The _exit function currently passes -1 as a "sig" to the _kill function as an
invalid signal number so that _kill can distinguish between an abort and a
standard exit.
For boards using the SYS_EXIT_EXTENDED semi-hosting operation to return a
status code, this means that the "status" paramter to _exit is ignored and the
return code is always -1.
https://developer.arm.com/docs/100863/latest/semihosting-operations/sys_exit_extended-0x20
This patch puts shared code between _kill and _exit into a new function
_kill_shared that takes the semi-hosting "reason" to use (if semi-hosting is
available) as an argument.
For semi-hosting _kill_shared provides that "reason".
Without the "sig" argument being used to distinguish between a normal and
abnormal exit, the _exit function can provide the return code to be used if the
SYS_EXIT_EXTENDED operation is available.
Hence the exit code can be returned.
This patch is similar the arm one committed recently.
2018-10-08 Christophe Lyon <christophe.lyon@linaro.org>
* libgloss/aarch64/syscalls.c (_sbrk): Fix prototype.
(_getpid, _write, _swiwrite, _lseek, _swilseek, _read, _wriread):
Likewise.
AngelSWI_Reason_ReportException does not return accoring to the ARM
documentation, so it is valid to mark _kill() as noreturn. This way,
the compiler does not warn about _exit() returning a value despite
being noreturn.
2018-10-01 Christophe Lyon <christophe.lyon@linaro.org>
* libgloss/arm/_exit.c (_exit): Declare _kill() as noreturn.
* libgloss/arm/_exit.c (_kill): Likewise. Remove the return
statements.
* newlib/libc/sys/arm/syscalls.c (_kill): Likewise..
It's been a while... I see the CRIS port broke with the
time_t-default-to-64-bit change, observable by a few test-cases in the
gcc fortran(!) tests failing, regressing when trying a recent newlib.
This is a two-part belt-and-suspenders change: adjust the CRIS port
gettimeofday syscall (the only one in newlib/CRIS passing a time_t or
struct timeval) to handle a userspace 64-bit time_t and secondly default
time_t to 32-bit long anyway. I considered making the local
"kernel_timeval" copy in _gettimeofday conditional on (userspace) time_t
being 64 bits, but thought it not worth bothering with the few move insns.
The effect of a 64-bit time_t is however observable as longer simulation
time when running the gcc testsuite and as bigger binaries without any
actual upside from the larger time_t size, so I thought better make the
default for this port go back to being a "long" again.
Tested by running the gcc testsuite over the three combinations of two
parts of the patch and observing the expected changes. Committed.
libgloss:
Adjust for syscall and userspace having different time_t or timeval.
* cris/linunistd.h (kernel_time_t, kernel_suseconds_t, kernel_timeval):
New types.
(gettimeofday): Change the type of the first argument to be a
pointer to a struct kernel_timeval.
* cris/gensyscalls (_gettimeofday): Use an intermediate struct
kernel_timeval for the syscall and initialize the result from
that.
Signed-off-by: Hans-Peter Nilsson <hp@axis.com>
Upon successful completion, times() shall return the elapsed real time,
in clock ticks, since an arbitrary point in the past (for example,
system start-up time).
Signed-off-by: Kito Cheng <kito.cheng@gmail.com>
Introduce new host configuration variable "have_init_fini" which is set
to "yes" by default. Override it for RISC-V to "no".
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
The current SYS_EXIT has a bug that when making the call it always uses
the v2 calling convention. This is undefined behavior according to the
semihosting specification:
https://developer.arm.com/docs/100863/latest/semihosting-operations/sys_exit-0x18
This patch fixes it by making sure v1 passes the argument directly in the register instead
of in a block. And for v2 it does the same if the v2 extension isn't supported.
The sequence generated now is
12424: ebfffecd bl 11f60 <_has_ext_exit_extended>
12428: e3500000 cmp r0, #0
1242c: 11a0500d movne r5, sp
12430: 059d5000 ldreq r5, [sp]
12434: e1a00004 mov r0, r4
12438: e1a01005 mov r1, r5
1243c: ef00f000 svc 0x0000f000
Signed-off-by: Tamar Christina <tamar.christina@arm.com>
Previously, hw exception handler stub and interrupt handler stub for microbaze were unable to
be overwritten. Change to weak to fix this.
Signed-off-by: Ben Levinsky <ben.levinsky@xilinx.com>
The previous multi-build implementation was copying the config.status from the parent
multilib directory when building the different semihosting variants. It did so because
the configuration doesn't change. However when you use a relative path to configure it
turns out that the paths inside the config.status are also relative.
To fix this, the srcdir is adjusted from the initial configuration instead of copying it.
Tested on aarch64-none-elf and arm-none-eabi.
Signed-off-by: Tamar Christina <tamar.christina@arm.com>
- For prevent confuse about what BSD license variant we used, 2- or
3-clause license, we change the license to FreeBSD license to make
it unambiguously refers to the 2-clause license.
Nowadays, the code fetching command line options via semi-hosting are
unconditionally pulled in, so that the semi-hosting code is still
there even I compile with option --specs=nosys.specs.
gdb ./aarch64-none-elf/libgloss/aarch64/crt0.o
(gdb) disassemble _start
0x0000000000000050 <+80>: ldr x1, 0x128 <_cpu_init_hook+48>
0x0000000000000054 <+84>: mov w0, #0x15
0x0000000000000058 <+88>: hlt #0xf000
This patch fixes this problem by wrapping the code by ARM_RDI_MONITOR.
When semi-hosting is not used, set command line options to NULL.
On AArch64 we currently always link in crt0 regardless of if another
one is being provided by something else, like rdimon.a. This was never
an issue before as nosys was not supported on AArch64.
This updates the specs to supply a different crt0 when a semihosting
call is required.
Signed-off-by: Tamar Christina <tamar.christina@arm.com>
This fixed the compile for nosys and validation specs
but nosys won't run because of existing limitations to
aarch64's syscalls.c, it requires semihosting to get
commandline arguments and heap info without having a
fallback method as ARM does.
Signed-off-by: Tamar Christina <tamar.christina@arm.com>
This patch fixes the issue where nosys.specs is used to link.
e.g. The use of crt0 without any support for semihosting requested.
The AArch64 crt0 was missing an #ifdef for the initialise_monitor_handles
which was causing the link to fail. Sorry for missing this before.
Semihosting v2 changes are documented here:
https://developer.arm.com/docs/100863/latest/
The biggest change is the addition of an extensions mechanism
to add more extensions in the future.
Signed-off-by: Tamar Christina <tamar.christina@arm.com>
Sandra Loosemore
Jeff Johnston
Tamar Christina
Jim Wilson
Matthew Malcomson
Christophe Lyon
Hans-Peter Nilsson
Denis Ivanov
Sebastian Huber
Ben Levinsky
Jaap de Wolff
Chih-Mao Chen
Yaakov Selkowitz
Alexander Fedotov
Alexander Fedotov-B55613
Kito Cheng
Kito Cheng
Szabolcs Nagy
Yao Qi