Various address spaces from the BCM2835 are reported as
'anonymous' in memory tree:

  (qemu) info mtree

  address-space: anonymous
    0000000000000000-000000000000008f (prio 0, i/o): bcm2835-mbox
      0000000000000010-000000000000001f (prio 0, i/o): bcm2835-fb
      0000000000000080-000000000000008f (prio 0, i/o): bcm2835-property

  address-space: anonymous
    0000000000000000-00000000ffffffff (prio 0, i/o): bcm2835-gpu
      0000000000000000-000000003fffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff
      0000000040000000-000000007fffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff
      000000007e000000-000000007effffff (prio 1, i/o): alias bcm2835-peripherals @bcm2835-peripherals 0000000000000000-0000000000ffffff
      0000000080000000-00000000bfffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff
      00000000c0000000-00000000ffffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff

  [...]

Since the address_space_init() function takes a 'name' argument,
set it to correctly describe each address space:

  (qemu) info mtree

  address-space: bcm2835-mbox-memory
    0000000000000000-000000000000008f (prio 0, i/o): bcm2835-mbox
      0000000000000010-000000000000001f (prio 0, i/o): bcm2835-fb
      0000000000000080-000000000000008f (prio 0, i/o): bcm2835-property

  address-space: bcm2835-fb-memory
    0000000000000000-00000000ffffffff (prio 0, i/o): bcm2835-gpu
      0000000000000000-000000003fffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff
      0000000040000000-000000007fffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff
      000000007e000000-000000007effffff (prio 1, i/o): alias bcm2835-peripherals @bcm2835-peripherals 0000000000000000-0000000000ffffff
      0000000080000000-00000000bfffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff
      00000000c0000000-00000000ffffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff

  address-space: bcm2835-property-memory
    0000000000000000-00000000ffffffff (prio 0, i/o): bcm2835-gpu
      0000000000000000-000000003fffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff
      0000000040000000-000000007fffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff
      000000007e000000-000000007effffff (prio 1, i/o): alias bcm2835-peripherals @bcm2835-peripherals 0000000000000000-0000000000ffffff
      0000000080000000-00000000bfffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff
      00000000c0000000-00000000ffffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff

  address-space: bcm2835-dma-memory
    0000000000000000-00000000ffffffff (prio 0, i/o): bcm2835-gpu
      0000000000000000-000000003fffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff
      0000000040000000-000000007fffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff
      000000007e000000-000000007effffff (prio 1, i/o): alias bcm2835-peripherals @bcm2835-peripherals 0000000000000000-0000000000ffffff
      0000000080000000-00000000bfffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff
      00000000c0000000-00000000ffffffff (prio 0, i/o): alias bcm2835-gpu-ram-alias[*] @ram 0000000000000000-000000003fffffff
Signed-off-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: NAlistair Francis <alistair.francis@wdc.com>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NCleber Rosa <crosa@redhat.com>
Message-id: 20190926173428.10713-4-f4bug@amsat.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Various logging improvements as once:
- Use 0x prefix for hex numbers
- Display value written during write accesses
- Move some logs from GUEST_ERROR to UNIMP
Signed-off-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: NAlistair Francis <alistair.francis@wdc.com>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NCleber Rosa <crosa@redhat.com>
Message-id: 20190926173428.10713-3-f4bug@amsat.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

IEC binary prefixes ease code review: the unit is explicit.
Signed-off-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: NAlistair Francis <alistair.francis@wdc.com>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NCleber Rosa <crosa@redhat.com>
Message-id: 20190926173428.10713-2-f4bug@amsat.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Message-id: 20190925143248.10000-24-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The AST2600 SoC has an extra controller to set the PHY registers.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-23-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

To support the ast2600's four MACs allow SoCs to specify the number
they have, and create that many.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Message-id: 20190925143248.10000-22-clg@kaod.org
[clg: - included a check on sc->macs_num when realizing the macs
      - included interrupt definitions for the AST2600 ]
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-20-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Initial definitions for a simple machine using an AST2600 SoC (Cortex
CPU).

The Cortex CPU and its interrupt controller are too complex to handle
in the common Aspeed SoC framework. We introduce a new Aspeed SoC
class with instance_init and realize handlers to handle the differences
with the AST2400 and the AST2500 SoCs. This will add extra work to
keep in sync both models with future extensions but it makes the code
clearer.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-19-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

It prepares ground for the AST2600.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-18-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The I2C controller of the AST2400 and AST2500 SoCs have one IRQ shared
by all I2C busses. The AST2600 SoC I2C controller has one IRQ per bus
and 16 busses.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-17-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

It prepares ground for register differences between SoCs.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-16-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The AST2600 has the same sets of 3.6v gpios as the AST2400 plus an
addtional two sets of 1.8V gpios.
Signed-off-by: NRashmica Gupta <rashmica.g@gmail.com>
Reviewed-by: NCédric Le Goater <clg@kaod.org>
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Acked-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-15-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The AST2600 SoC SMC controller is a SPI only controller now and has a
few extensions which we will need to take into account when SW
requires it. This is enough to support u-boot and Linux.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Acked-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-14-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

AST2600 will use a different encoding for the addresses defined in the
Segment Register.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Acked-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-13-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The AST2600 has four watchdogs, and they each have a 0x40 of registers.

When running as part of an ast2600 system we must check a different
offset for the system reset control register in the SCU.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Message-id: 20190925143248.10000-12-clg@kaod.org
[clg: - reworked model integration into new object class ]
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

It cleanups the current models for the Aspeed AST2400 and AST2500 SoCs
and prepares ground for future SoCs.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-11-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The AST2600 SDMC controller is slightly different from its predecessor
(DRAM training). Max memory is now 2G on the AST2600.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Message-id: 20190925143248.10000-10-clg@kaod.org
[clg: - improved commit log
      - reworked model integration into new object class ]
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Use class handlers and class constants to differentiate the
characteristics of the memory controller and remove the 'silicon_rev'
property.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-9-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The AST2600 timer replaces control register 2 with a interrupt status
register. It is set by hardware when an IRQ occurs and cleared by
software.

Modify the vmstate version to take into account the new fields.

Based on previous work from Joel Stanley.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-8-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The AST2600 timer has a third control register that is used to
implement a set-to-clear feature for the main control register.

On the AST2600, it is not configurable via 0x38 (control register 3)
as it is on the AST2500.

Based on previous work from Joel Stanley.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-7-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The AST2500 timer has a third control register that is used to
implement a set-to-clear feature for the main control register.

This models the behaviour expected by the AST2500 while maintaining
the same behaviour for the AST2400.

The vmstate version is not increased yet because the structure is
modified again in the following patches.

Based on previous work from Joel Stanley.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-6-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The most important changes will be on the register range 0x34 - 0x3C
memops. Introduce class read/write operations to handle the
differences between SoCs.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-5-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The SCU controller on the AST2600 SoC has extra registers. Increase
the number of regs of the model and introduce a new field in the class
to customize the MemoryRegion operations depending on the SoC model.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Message-id: 20190925143248.10000-4-clg@kaod.org
[clg: - improved commit log
      - changed vmstate version
      - reworked model integration into new object class
      - included AST2600_HPLL_PARAM value ]
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The Aspeed SOCs have two SD/MMC controllers. Add a device that
encapsulates both of these controllers and models the Aspeed-specific
registers and behavior.

Tested by reading from mmcblk0 in Linux:
qemu-system-arm -machine romulus-bmc -nographic \
 -drive file=flash-romulus,format=raw,if=mtd \
 -device sd-card,drive=sd0 -drive file=_tmp/kernel,format=raw,if=sd,id=sd0
Signed-off-by: NEddie James <eajames@linux.ibm.com>
Reviewed-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Message-id: 20190925143248.10000-3-clg@kaod.org
[clg: - changed the controller MMIO window size to 0x1000
      - moved the MMIO mapping of the SDHCI slots at the SoC level
      - merged code to add SD drives on the SD buses at the machine level ]
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

When WDT_RESTART is written, the data is not the contents
of the WDT_CTRL register. Hence ensure we are looking at
WDT_CTRL to check if bit WDT_CTRL_1MHZ_CLK is set or not.
Signed-off-by: NAmithash Prasad <amithash@fb.com>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Message-id: 20190925143248.10000-2-clg@kaod.org
[clg: improved Suject prefix ]
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

SH_EXT_STDOUT_STDERR is a v2.0 semihosting extension: the guest
can open ":tt" with a file mode requesting append access in
order to open stderr, in addition to the existing "open for
read for stdin or write for stdout". Implement this and
report it via the :semihosting-features data.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Message-id: 20190916141544.17540-16-peter.maydell@linaro.org

SH_EXT_EXIT_EXTENDED is a v2.0 semihosting extension: it
indicates that the implementation supports the SYS_EXIT_EXTENDED
function. This function allows both A64 and A32/T32 guests to
exit with a specified exit status, unlike the older SYS_EXIT
function which only allowed this for A64 guests. Implement
this extension.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Message-id: 20190916141544.17540-15-peter.maydell@linaro.org

Version 2.0 of the semihosting specification added support for
allowing a guest to detect whether the implementation supported
particular features. This works by the guest opening a magic
file ":semihosting-features", which contains a fixed set of
data with some magic numbers followed by a sequence of bytes
with feature flags. The file is expected to behave sensibly
for the various semihosting calls which operate on files
(SYS_FLEN, SYS_SEEK, etc).

Implement this as another kind of guest FD using our function
table dispatch mechanism. Initially we report no extended
features, so we have just one feature flag byte which is zero.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Message-id: 20190916141544.17540-14-peter.maydell@linaro.org

Factor out the implementation of SYS_FLEN via the new
function tables.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190916141544.17540-13-peter.maydell@linaro.org

Factor out the implementation of SYS_SEEK via the new function
tables.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190916141544.17540-12-peter.maydell@linaro.org

Factor out the implementation of SYS_ISTTY via the new function
tables.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190916141544.17540-11-peter.maydell@linaro.org

Factor out the implementation of SYS_READ via the
new function tables.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190916141544.17540-10-peter.maydell@linaro.org

Factor out the implementation of SYS_WRITE via the
new function tables.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-9-peter.maydell@linaro.org

Currently for the semihosting calls which take a file descriptor
(SYS_CLOSE, SYS_WRITE, SYS_READ, SYS_ISTTY, SYS_SEEK, SYS_FLEN)
we have effectively two implementations, one for real host files
and one for when we indirect via the gdbstub. We want to add a
third one to deal with the magic :semihosting-features file.

Instead of having a three-way if statement in each of these
cases, factor out the implementation of the calls to separate
functions which we dispatch to via function pointers selected
via the GuestFDType for the guest fd.

In this commit, we set up the framework for the dispatch,
and convert the SYS_CLOSE call to use it.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-8-peter.maydell@linaro.org

When we are routing semihosting operations through the gdbstub, the
work of sorting out the return value and setting errno if necessary
is done by callback functions which are invoked by the gdbstub code.
Clean up some ifdeffery in those functions by having them call
set_swi_errno() to set the semihosting errno.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-7-peter.maydell@linaro.org

The semihosting code needs accuss to the linux-user only
TaskState pointer so it can set the semihosting errno per-thread
for linux-user mode. At the moment we do this by having some
ifdefs so that we define a 'ts' local in do_arm_semihosting()
which is either a real TaskState * or just a CPUARMState *,
depending on which mode we're compiling for.

This is awkward if we want to refactor do_arm_semihosting()
into other functions which might need to be passed the TaskState.
Restrict usage of the TaskState local by:
 * making set_swi_errno() always take the CPUARMState pointer
   and (for the linux-user version) get TaskState from that
 * creating a new get_swi_errno() which reads the errno
 * having the two semihosting calls which need the TaskState
   for other purposes (SYS_GET_CMDLINE and SYS_HEAPINFO)
   define a variable with scope restricted to just that code
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-6-peter.maydell@linaro.org

Currently the Arm semihosting code returns the guest file descriptors
(handles) which are simply the fd values from the host OS or the
remote gdbstub. Part of the semihosting 2.0 specification requires
that we implement special handling of opening a ":semihosting-features"
filename. Guest fds which result from opening the special file
won't correspond to host fds, so to ensure that we don't end up
with duplicate fds we need to have QEMU code control the allocation
of the fd values we give the guest.

Add in an abstraction layer which lets us allocate new guest FD
values, and translate from a guest FD value back to the host one.
This also fixes an odd hole where a semihosting guest could
use the semihosting API to read, write or close file descriptors
that it had never allocated but which were being used by QEMU itself.
(This isn't a security hole, because enabling semihosting permits
the guest to do arbitrary file access to the whole host filesystem,
and so should only be done if the guest is completely trusted.)

Currently the only kind of guest fd is one which maps to a
host fd, but in a following commit we will add one which maps
to the :semihosting-features magic data.

If the guest is migrated with an open semihosting file descriptor
then subsequent attempts to use the fd will all fail; this is
not a change from the previous situation (where the host fd
being used on the source end would not be re-opened on the
destination end).
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-5-peter.maydell@linaro.org

In arm_gdb_syscall() we have a comment suggesting a race
because the syscall completion callback might not happen
before the gdb_do_syscallv() call returns. The comment is
correct that the callback may not happen but incorrect about
the effects. Correct it and note the important caveat that
callers must never do any work of any kind after return from
arm_gdb_syscall() that depends on its return value.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-4-peter.maydell@linaro.org

If we fail a semihosting call we should always set the
semihosting errno to something; we were failing to do
this for some of the "check inputs for sanity" cases.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-3-peter.maydell@linaro.org

The set_swi_errno() function is called to capture the errno
from a host system call, so that we can return -1 from the
semihosting function and later allow the guest to get a more
specific error code with the SYS_ERRNO function. It comes in
two versions, one for user-only and one for softmmu. We forgot
to capture the errno in the softmmu version; fix the error.

(Semihosting calls directed to gdb are unaffected because
they go through a different code path that captures the
error return from the gdbstub call in arm_semi_cb() or
arm_semi_flen_cb().)
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-2-peter.maydell@linaro.org