TODO

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PA-RISC Linux TODO (actually this is Helge's TODO list)

Status & TODO 2016-03-17

  • add wiki page about kernel cross-compiling
  • Kernel: still missing Linux kernel development (no patches available yet):
    • Fix kernel to load -fpie compiled programs not at 0x400000
    • maybe implement transparent huge pages (due to cache coherency technically only possible on PA8500-PA8700 CPUs, not possible on PA8800-PA8900 CPUs)
    • Fix FTRACE: https://patchwork.kernel.org/patch/3554391/
    • optimize flush_dcache_page() implementation like sparc. See Documentation/cachetlb.txt, e.g. used in aio subsystem
    • Implement CONFIG_DEBUG_STACK_USAGE ?
    • fix wrong _init notation in kernel
    • NO_IRQ -> should be converted to (0) instead of (-1) -> Helge (check assembly, check in drivers/parisc/*)
    • implement alternative coding for UP/SMP. See arch/x86/include/asm/alternative.h
    • check assembly in drivers/parisc/*
    • use pdc_add_valid() in kern_addr_valid(), protect against crashable acesses (like for superio-pc-drivers-detection in lp), add pdc_add_valid() to create a probe_kernel_read() implementation.
    • arch/parisc/kernel/sys_parisc.c -> use SYSCALL_ALIAS() -> maybe
    • implement libnuma kernel support to report on C8000 one socket with 2 cores.
    • Review gettimeofday and clock_gettime() implementation, possibly use a light-weight-syscall and rely on cr16 and cpu speed for more accurate timing? similiar to commit http://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?id=18ad51dd342a7eb09dbcd059d0b451b616d4dafc
  • Kernel: Low priority patches needs further work
    • disable FP-register save/restore at kernel entry? - https://patchwork.kernel.org/patch/3975291/
    • enable 16k/64k kernel page sizes (still cacheflushing-issues with SCSI driver, additional work in glibc needed to deal with >4k page size, e.g. ld-loader alignments of data/code segments)
    • Superdome support - can someone test? Should work better now with latest kernels.
    • Visualize FX support (will probably never happen!)
    • implement BUG() and WARN() with inline assembly so that interrupt happens in delay branch of "or,<> %r0,cond,%r0". Probably not possible, because gcc will report "control reaches end of non-void function" warnings/errors.
  • Debian packages / Userspace work
    • IMPORTANT: fix OpenJDK - fixes required in zeroport (stack grows up!).
    • Fix qemu
    • 64-bit userspace, 64-bit binutils needs to be fixed to get multiple stub section support.
    • gcc -> join 32- and 64bit compiler, make "-m64" work, get rid of hppa64-linux-gnu-gcc
  • userspace
  • palo (PA-RISC Boot Loader):
    • Modify (if possible), that palo can read (sequential) tftpbootable-vmlinuxes as well as the current boot-vmlinux images (simplifies build/handling)
    • move decompression of Kernel to Linux kernel code instead of palo

Upstream PA-RISC-related kernel patch history

Debian kernel and userspace programs

  • Debian kernel / Generic Kernel bugs fixed
    • DONE: Fixed 64bit SMP kernel & sticon on machines with more than 4GB RAM (Kernel 3.12)
    • DONE: Lots of syscall fixes regarding compat kernel
    • DONE: send patches to remove UP from debian kernels, use sil680 instead of siimage, see http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=721191 -> fixed in 3.12 / 3.13
    • DONE: Enable BMC in c8000 default kernel config - ipmi driver (CONFIG_IPMI_HANDLER=y) - http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=747482
    • DONE: remove HIL RTC from debian kernel - it creates a backtrace at boot because we have already another rtc0 active.
    • DONE: add ppdev driver, needed by CUPS, systemd reports missing module load (3.17 & 3.16 kernel)
    • DONE: Add crc-modules, event, isofs, jfs, mouse, sata, sound, squashfs, udf, uinput, scsi-common, scsi-extra, loop, serial and usb-serial debian-installer packages
    • DONE: Kernel build problem: a) disable -mfast-indirect-calls in Makefile, b) gcc compiler bug in > gcc-4.8.3-3
    • DONE: Drop HPUX-support from kernel (Kernel 4.0)
    • DONE: implemented HUGE pages
    • DONE: kernel timerfd_settime/timerfd_gettime issue, test with debian package: liblinux-fd-perl -> https://patchwork.kernel.org/patch/7951661/, backported to all kernels
    • DONE: kernel ptrace bug: http://thread.gmane.org/gmane.linux.ports.parisc/26273, possible fix: https://patchwork.kernel.org/patch/8063301/

ABI breakages (HP-UX support)

parisc-linux.org Homepage and Debian build server infrastructure work

Testsuites, kernel and userspace testing tools

  • GLIBC issues: https://sourceware.org/glibc/wiki/PortStatus
  • We also have a problem with poll in rpcbind on 32-bit kernels. Runs forever. Not analyzed yet.
  • glib2.0 atomic bug: Dave: I see the problem building various packages -- apt is is one. It occurs when multiple dot processes are started by graph when package documentation is being generated. The number of dot processes spawned depends on the number of processors on the build system. However, the faults occur even on a UP system. I debugged one of these segvs enough to see that the problem occurred in a glib2.0 library. It's using the GCC "sync" interface.
  • From Dave: gcc thread issues including thread cancellation, glib2.0 problem, maybe __tls_get_addr clobber too?

TODO Drivers

  • IPMI support on rp-class / Support graceful shutdown from BMC on rp servers (`PC -GRACEFUL`)
  • write Lasi floppy driver
  • write Suckyio floppy driver
  • write spifi driver (rbrad)
  • modify ncr53c8xx driver for Outfield (735 & 755)
  • write GSC FDDI driver
  • write Timi ASIC (74x) support
  • EISA DMA support

Review all the todo entries below!

  • ns87415 dma doesn't work reliably on suckyio-systems
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