From fdb00bbb3de5bcda0d119bd06e7ec00cf4a570e2 Mon Sep 17 00:00:00 2001 From: Sebastian Huber Date: Mon, 23 May 2022 16:14:09 +0200 Subject: libbsd.txt: Move issues and TODO --- CONTRIBUTING.rst | 124 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) (limited to 'CONTRIBUTING.rst') diff --git a/CONTRIBUTING.rst b/CONTRIBUTING.rst index c7c35df9..8cf42dff 100644 --- a/CONTRIBUTING.rst +++ b/CONTRIBUTING.rst @@ -599,3 +599,127 @@ 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) `_. + +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? + +* : 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. -- cgit v1.2.3