NuttX TODO List (Last updated February 13, 2008) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ (6) Task/Scheduler (sched/) (1) Dynamic loader (N/A) (2) Memory Managment (mm/) (1) Signals (sched/, arch/) (1) pthreads (sched/) (1) C++ Support (11) Network (net/, netutils/) (2) USB (drivers/usbdev) (3) Libraries (lib/) (3) File system/Generic drivers (fs/, drivers/) (1) Pascal add-on (pcode/) (2) Documentation (Documentation/) (3) Build system (0) Applications & Tests (examples/) (1) ARM (arch/arm/) (1) ARM/C5471 (arch/arm/src/c5471/) (1) ARM/DM320 (arch/arm/src/dm320/) (2) ARM/LPC214x (arch/arm/src/lpc214x/) (4) pjrc-8052 / MCS51 (arch/pjrc-8051/) (6) z80/z8 (arch/z80/) (7) z16 (arch/z16/) o Task/Scheduler (sched/) ^^^^^^^^^^^^^^^^^^^^^^^ Description: When a tasks exits, shouldn't all of its child pthreads also be terminated? Status: Open Priority: Medium, required for good emulation of process/pthread model. Description: atexit() supports registration of one function called on exit(). Should task_delete() also cause atexit() function to be called? Status: Open Priority: Low, task_delete() is non-standard and its behavior is unspecified. Description: Implement sys/mman.h and functions Status: Open Priority: Low Description: Implement sys/wait.h and functions. Consider implementing wait, waitpid, waitid. At present, a parent has no information about child tasks. Status: Open Priority: Low Description: Implement priority inheritance Status: Open Priority: Medium, this is a good feature for realtime systems. Description: Several APIs do not set errno. Need to review all APIs. Status: Open Priority: Medium, required for standard compliance (but makes the code bigger) o Dynamic Loader ^^^^^^^^^^^^^^ Description: At some point in the future, I intend to port the XFLAT dynamic loader into NuttX (see http://xflat.sourceforge.net/). That would allow NuttX to dynamically load and link external code in a mounted filesystem. Status: Open Priority: Low, Nice feature and I might do it someday o Memory Managment (mm/) ^^^^^^^^^^^^^^^^^^^^^^ Description: Add an option to free all memory allocated by a task when the task exits. This is probably not be worth the overhead for a deeply embedded system. Status: Open Priority: Medium/Low, a good feature to prevent memory leaks but would have negative impact on memory usage and code size. Description: Current logic adapts size_t for 16-bit address machines vs. 32-bit address machines. But a small memory option should also be provided so that the small offset option can be used with 32-bit machines that have small RAM memories (like the lpc2148) Status: Open Priority: High, a good feature enhancement. o Signals (sched/, arch/) ^^^^^^^^^^^^^^^^^^^^^^^ Description: 'Standard' signals and signal actions are not supported. (e.g., SIGINT, SIGCHLD, SIGSEGV, etc). Status: Open Priority: Low, required by standards but not so critical for an embedded system. o pthreads (sched/) ^^^^^^^^^^^^^^^^^ Description: pthread_cancel(): Should implement cancellation points and pthread_testcancel() Status: Open Priority: Low, probably not that useful o C++ Support ^^^^^^^^^^^ Description: Need to call static constructors Status: Open Priority: Low, depends on toolchain. Call to gcc's built-in static constructor logic will probably have to be performed by user logic in user_start(). o Network (net/, netutils/) ^^^^^^^^^^^^^^^^^^^^^^^^^ Description: Several of the netutils/ apps are untested. These include uIP's netutils/smtp, dhcpd, resolv, webclient. Only minimal testing of the others has been performed. Status: Open Priority: Medium, Important but not core NuttX functionality Description: Should implement SOCK_RAW, SOCK_PACKET Status: Open Priority: Low Description: uIP polling issues / Multiple network interface support: (1) Current logic will not support multiple ethernet drivers. Each driver should poll on TCP connections connect on the network supported by the driver; UDP polling should respond with TX data only if the UDP packet is intended for the the network supported by the driver. (2) If there were multiple drivers, polling would occur at double the rate. Fix by using bound IP address in TCP connection (lipaddr) and verifying that it is in the subnet served by the driver. Status: Open Priority: Medium, The feature is not important, but it is important for NuttX to resolve the architectural issues. Description: Sendoto() and multiple network interface support: When polled, would have to assure that the destination IP is on the subnet served by the polling driver. Status: Open Priority: Medium, The feature is not important, but it is important for NuttX to resolve the architectural issues. Description: uIP/Socket callback logic is not thread safe. This means that a socket cannot be used concurrently by two threads. Minimal fix: Add mutex to support exclusion for protection. Status: Open Priority: Low. The currently socket design cannot be use concurrently by threads with out a major redesign. The feature is not of great value since the use model for multi-thread sockets is not common. Adding mutex support would only mask the underlying issue. Description: IPv6 support is incomplete Status: Open Priority: Medium Description: Incoming UDP broadcast should only be accepted if listening on INADDR_ANY(?) Status: Open Priority: Low Description: Read-ahead buffers capture incoming TCP data when no user thread is recv-ing the data. Should add some driver call to support throttling; when there is no listener for new data, the driver should be throttled. Perhaps the driver should disable RX interrupts when throttled and re-anable on each poll time. recvfrom would, of course, have to un-throttle. Status: Open Priority: Medium Description: Need to standardize collection of statistics from network drivers. examples/nsh ifconfig command should present statistics. Status: Open Priority: Low Description: Outgoing packets are dropped and overwritten by ARP packets if the destination IP has not been mapped to a MAC. Could improve send() performance by explicitly performing ARP before sending the packet. Status: Open Priority: Medium Description: Port PPP support from http://contiki.cvs.sourceforge.net/contiki/contiki-2.x/backyard/core/net/ppp/ Status: Open Priority: Low o USB (drivers/usbdev) ^^^^^^^^^^^^^^^^^^^^ Description: Implement USB device support Status: Open Priority: High Description: Implement USB bulk / serial device support Status: Open Priority: High o Libraries (lib/) ^^^^^^^^^^^^^^^^ Description: sscanf() and lib_vsprintf() do not support floating point values. Status: Open Priority: Low Description: The definition of environ in stdlib.h is bogus and will not work as it should. This is because the underlying representation of the environment is not an arry of pointers. Status: Open Priority: Medium Description: There are two different copies of getenv(): One in sched/env_getenv.c and one in lib/lib_getenv(). Keep one. Status: Open Priority: Low o File system / Generic drivers (fs/, drivers/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Description: Add chmod(), truncate(). Status: Open Priority: Low Description: FAT32: long file names Status: Open Priority: Medium Description: The CAN driver is untested. Add a test for the CAN driver. Status: Open Priority: Medium o Pascal Add-On (pcode/) ^^^^^^^^^^^^^^^^^^^^^^ Description: Need APIs to verify execution of P-Code from memory buffer. Status: Open Priority: Low Description: Loader and object format may be too large for some small memory systems. Consider ways to reduce memory footprint. Status: Open Priority: Medium o Documentation (Documentation/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Description: Document driver/ logic Status: Open Priority: Low Description: Document C-library APIs Status: Open Priority: Low o Build system ^^^^^^^^^^^^ Description: Some names under arch are still incorrect. These should be processor architecture names: pjrc-8051 should be 805x Status: Open Priority: Low Description: configs/pjrc-8051 should be configs/pjrc-87c52 Status: Open Priority: Low Description: Dependencies do not work correctly under configs//src (same as arch//src/board). Seems to be worse using SDCC. Status: Open Priority: Medium (maybe higher for z80 target) o Applications & Tests (examples/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ o ARM (arch/arm/) ^^^^^^^^^^^^^^^ Description: Add option to use a separate stack for interrupt handling. At present, each interrupt executes on top of the user stack allocation making each user stack allocation larger than needed. Status: Open Priority: Medium o ARM/C5471 (arch/arm/src/c5471/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Description: UART re-configuration is untested and conditionally compiled out. Status: Open Priority: Medium. ttyS1 is not configured, but not used; ttyS0 is configured by the bootloader o ARM/DM320 (arch/arm/src/dm320/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Description: config/ntos-dm320: It seems that when a lot of debug statements are added, the system no longer boots. This is suspected to be a stack problem: Making the stack bigger or removing arrays on the stack seems to fix the problem (might also be the bootloader overwriting memory) Status: Open Priority: Medium o ARM/LPC214x (arch/arm/src/lpc214x/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Description: Finish bringup Status: Open Priority: High Description: Add MMC and USB support Status: Open Priority: Mediam o pjrc-8052 / MCS51 (arch/pjrc-8051/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Description: Current status: - Basic OS task management seems OK - Fails when interrupts enabled. The stack pointer is around 0x6e before the failure occurs. It looks like some issue when the stack pointer moves from the directly to indirectly addressable region (0x80 boundary). - Work on the 8052 is temporarily on hold Status: Open Priority: Low, 8051 is a tough platform because of the tiny stack. Description: Use timer 0 as system timer. Timer 2 is needed for second UART. Logic is implemented, but there needs to be a system configuration to change the ticks-per-second value to match the timer interrupt rate Status: Open Priority: Low Description: During build, there are several integer overflows reported: sched/gmtime_r.c aroud lines 184 and 185 sched/clock_initialize.c at line 107 sched/pthread_create.c at 330 examples/ostest/barrier.c around lines 53 and 74 examples/ostest/sighand.c at 225 and 244 driver/serial.c in usleep calls around 347 and 354 Status: Open Priority: Medium Description Global data is not being initialized. Logic like that of SDCCs crt0*.s needs to be incorporated into the system boot logic Status: Open Priority: Low -- only because there as so many other issues with 8051 o z80/z8 (arch/z80) ^^^^^^^^^^^^^^^^^^ Description: The SDCC version the same problems with interger overflow during compilation as described for pjrc-8051. At typical cause is code like usleep(500*1000) which exceeds the range of a 16-bit integer Status: See pjrc-8051 Priority: See pjrc-8051 Description: The simulated Z80 serial console (configs/z80sim/src/z80_serial.c + driver/serial.c) does not work. This is because there are no interrupts in the simulation so there is never any serial traffic. Status: Open Priority: Low -- the simulated console is not critical path and the designs to solve the problem are complex. Description: ZDS-II Librarian complains that the source for the .obj file is not in the library. Status: Open Priority: Low, thought to be cosmetic. I think this is a consequence of replacing vs. inserting the library. Description: The ZDS-II compiler (version 4.10.1) fails with an internal error while compiler mm/mm_initialize. This has been reported as incident 81509. I have found the following workaround that I use to build for the time being: --- mm/mm_initialize.c.SAVE 2008-02-13 08:06:46.833857700 -0600 +++ mm/mm_initialize.c 2008-02-13 08:07:26.367608900 -0600 @@ -94,8 +94,11 @@ { int i; +#if 0 /* DO NOT CHECK IN */ CHECK_ALLOCNODE_SIZE; CHECK_FREENODE_SIZE; +#endif /* Set up global variables */ Status: Open Priority: High Description: Add support for prioritized ez8 interrupts. Currently logic supports only nominal interrupt priority. Status: Open Priority: Low Description: The z8Encore! port has only been verified on the ZDS-II instruction set simulator. Status: Open Priority: Medium o z16 (arch/z16) ^^^^^^^^^^^^^^^^ Description: ZDS-II Librarian complains that the source for the .obj file is not in the library. Status: Open Priority: Low, thought to be cosmetic. I think this is a consequence of replacing vs. inserting the library. Description: When the interrupt-driven serial driver is used, the system hangs. This is because of TX ready (TRDE) interrupts that get lost while interrupts are disabled. The existing serial driver appears to be limited to hardware with a latching, level-sensitive TX ready interrupt. Status: Open Priority: Medium. A polled, write-only serial driver is used in the interim for system testing. Description: The system delays do not appear to be correct with the examples/ostest/timedmqueue.c test. Status: Open Priority: Medium-High Description: At present, the z16f port does not run properly when CONFIG_DEBUG is disabled: The obvious symptom is that there is no printf() output. I have isolated with problem to errors in optimization. With -reduceopt on the command line, I can get the printf output. However, there are still errors in the compiled code -- specifically in sched/timer_create.c. I have submitted a bug report to ZiLOG for this (support incident 81400). You can see the status of the bug report (and lots more technical detail) here: http://support.zilog.com/support/incident/incident_support.asp?iIncidentId=81400&iSiteId=1&chLanguageCode=ENG Summary of ZiLOG analysis: "This is a ZNEO compiler problem. ... [a] workaround is to replace: if ( !timerid || (clockid != 0) ) By: if ((clockid != 0) || !timerid)" Status: Open Priority: Medium-High Description: The pascal add-on does not work with the z16f (that is configuration z16f2800100zcog/pashello). This appears to be another ZDS-II error: when executing the instruction SYSIO 0, WRITESTR a large case statement is executed. This involves a call into the ZiLOG runtime library to __uwcase(). __uwcase is passed a pointer to a structure containing jump information. The cause of the failure appears to be that the referenced switch data is bad. This is submited as ZiLOG support incident 81459. Summary of ZiLOG analysis: "This is a ZNEO run time library problem. One workaround is to replace the line 58 in uwcase.asm From: ADD R9,#4 ; Skip handler To: ADD R9,#2 ; Skip handler And add uwcase.asm to the project. If the customer does not want to modify uwcase.asm then the other workaround is to add a dummy case and make it same as default: case 0x8000: default: This will make sure that uwcase is not called but ulcase is called." Status: Open. Due to licensing issues, I cannot include the modified uwcase in the NuttX code base. Priority: Medium Description: Add support to maintain SPOV in context switching. This improvement will provide protection against stack overflow and make a safer system solution. Status: Open Priority: Low Description: Add support for prioritized interrupts. Currently logic supports only nominal interrupt priority. Status: Open Priority: Low