libbsd.txt: Move issues and TODO

This commit is contained in:
Sebastian Huber 2022-05-23 16:14:09 +02:00
parent bb92546987
commit 593f7c1003

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@ -676,3 +676,127 @@ System Control Hints
If you get undefined references to ``_bsd_sysctl_*`` symbols, then you have to
locate and add the associated system control node, see
`SYSCTL(9) <http://www.freebsd.org/cgi/man.cgi?query=SYSCTL_DECL&sektion=9>`_.
Issues and TODO
===============
* PCI support on x86 uses a quick and dirty hack, see pci_reserve_map().
* Priority queues are broken with clustered scheduling.
* Per-CPU data should be enabled once the new stack is ready for SMP.
* Per-CPU NETISR(9) should be enabled onece the new stack is ready for SMP.
* Multiple routing tables are not supported. Every FIB value is set to zero
(= BSD_DEFAULT_FIB).
* Process identifiers are not supported. Every PID value is set to zero
(= BSD_DEFAULT_PID).
* User credentials are not supported. The following functions allow the
operation for everyone
* prison_equal_ip4(),
* chgsbsize(),
* cr_cansee(),
* cr_canseesocket() and
* cr_canseeinpcb().
* A basic USB functionality test that is known to work on Qemu is desirable.
* Adapt generic IRQ PIC interface code to Simple Vectored Interrupt Model
so that those architectures can use new TCP/IP and USB code.
* freebsd-userspace/rtems/include/sys/syslog.h is a copy from the old
RTEMS TCP/IP stack. For some reason, the __printflike markers do not
compile in this environment. We may want to use the FreeBSD syslog.h
and get this addressed.
* in_cksum implementations for architectures not supported by FreeBSD.
This will require figuring out where to put implementations that do
not originate from FreeBSD and are populated via the script.
* MAC support functions are not thread-safe ("freebsd/lib/libc/posix1e/mac.c").
* IFCONFIG(8): IEEE80211 support is disabled. This module depends on a XML
parser and mmap().
* get_cyclecount(): The implementation is a security problem.
* What to do with the priority parameter present in the FreeBSD synchronization
primitives and the thread creation functions?
* TASKQUEUE(9): Support spin mutexes.
* ZONE(9): Review allocator lock usage in rtems-bsd-chunk.c.
* KQUEUE(2): Choose proper lock for global kqueue list.
* TIMEOUT(9): Maybe use special task instead of timer server to call
callout_tick().
* sysctl_handle_opaque(): Implement reliable snapshots.
* PING6(8): What to do with SIGALARM?
* <sys/param.h>: Update Newlib to use a MSIZE of 256.
* BPF(4): Add support for zero-copy buffers.
* UNIX(4): Fix race conditions in the area of socket object and file node
destruction. Add support for file descriptor transmission via control
messages.
* PRINTF(9): Add support for log(), the %D format specifier is missing in the
normal printf() family.
* Why is the interrupt server used? The BSD interrupt handlers can block on
synchronization primitives like mutexes. This is in contrast to RTEMS
interrupt service routines. The BSPs using the generic interrupt support
must implement the ``bsp_interrupt_vector_enable()`` and
``bsp_interrupt_vector_disable()`` routines. They normally enable/disable a
particular interrupt source at the interrupt controller. This can be used to
implement the interrupt server. The interrupt server is a task that wakes-up
in case an associated interrupt happens. The interrupt source is disabled in
a generic interrupt handler that wakes-up the interrupt server task. Once
the postponed interrupt processing is performed in the interrupt server the
interrupt source is enabled again.
* Convert all BSP linkcmds to use a linkcmds.base so the sections are
easier to insert.
* NIC Device Drivers
* Only common PCI NIC drivers have been included in the initial set. These
do not include any system on chip or ISA drivers.
* PCI configuration probe does not appear to happen to determine if a
NIC is in I/O or memory space. We have worked around this by using a
static hint to tell the fxp driver the correct mode. But this needs to
be addressed.
* The ISA drivers require more BSD infrastructure to be addressed. This was
outside the scope of the initial porting effort.
* devfs (Device file system): There is a minimal implementation based on IMFS.
The mount point is fixed to "/dev". Note that the devfs is only used by the
cdev subsystem. cdev has been adapted so that the full path (including the
leading "/dev") is given to devfs. This saves some copy operations.
devfs_create() first creates the full path and then creates an IMFS generic
node for the device.
TBD: remove empty paths on devfs_destroy().
* altq_subr.c - Arbitrary choices were made in this file that RTEMS would not
support tsc frequency change. Additionally, the clock frequency for
machclk_freq is always measured for RTEMS.
* conf.h - In order to add make_dev and destroy_dev, variables in the cdev
structure that were not being used were conditionally compiled out. The
capability of supporting children did not appear to be needed and was not
implemented in the rtems version of these routines.
* Problem to report to FreeBSD: The MMAP_NOT_AVAILABLE define is inverted on
its usage. When it is defined the mmap method is called. Additionally, it is
not used thoroughly. It is not used in the unmap portion of the source. The
file rec_open.c uses the define MMAP_NOT_AVAILABLE to wrap the call to mmap
and file rec_close.c uses the munmap method.