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[00/43] semihosting cleanup

Message ID 20220430132932.324018-1-richard.henderson@linaro.org
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Series semihosting cleanup | expand

Message

Richard Henderson April 30, 2022, 1:28 p.m. UTC 
I had whipped up an rx-elf cross toolchain to test something
recently, and since I had built it, thought it would be easy
to use libgloss to run the multiarch hello and memory tests.
But we haven't implemented libgloss-style semihosting for rx.

I had forgotten how much boilerplate there is currently for
implementing semihosting for an architecture.  And we have 3
implementations that really could share much more code.

So: split out semihosting syscalls to individual functions,
and allow them to be wired up with a minimum of fuss.  Fix a
few bugs and to-do items on the way.

Still to do:

  * Merge semihosting console.c into GuestFD.
    The ARM semihosting spec has separate syscalls for console output,
    and expects the read/write syscalls to only apply to files.
    But the other semihosting implementations assume stdin/stdout,
    and we should be able to wire those up via the same mechanism.

  * Errno.  The ARM spec punts this entirely.  But we aren't even
    self-consistant, some paths returning host <errno.h> values,
    and anything going through gdbstub using the gdb remote
    file-io errno values.  The arm and nios2 specs explicitly
    call for the gdb values, which we are not doing.

  * tests/tcg/m68k semihosting implementation.

  * target/rx semihosting implementation.


r~


Richard Henderson (43):
  semihosting: Move exec/softmmu-semi.h to semihosting/softmmu-uaccess.h
  semihosting: Return failure from softmmu-uaccess.h functions
  semihosting: Improve condition for config.c and console.c
  semihosting: Move softmmu-uaccess functions out of line
  semihosting: Add target_strlen for softmmu-uaccess.h
  semihosting: Simplify softmmu_lock_user_string
  semihosting: Split out guestfd.c
  semihosting: Generalize GuestFDFeatureFile
  semihosting: Return void from do_common_semihosting
  semihosting: Adjust error checking in common_semi_cb
  semihosting: Move common-semi.h to include/semihosting/
  include/exec: Move gdb open flags to gdbstub.h
  include/exec: Move gdb_stat and gdb_timeval to gdbstub.h
  semihosting: Use struct gdb_stat in common_semi_flen_cb
  semihosting: Split is_64bit_semihosting per target
  semihosting: Split common_semi_flen_buf per target
  semihosting: Split out common_semi_has_synccache
  semihosting: Use env more often in do_common_semihosting
  semihosting: Move GET_ARG/SET_ARG earlier in the file
  semihosting: Split out semihost_sys_open
  semihosting: Split out semihost_sys_close
  semihosting: Split out semihost_sys_read
  semihosting: Split out semihost_sys_write
  semihosting: Bound length for semihost_sys_{read,write}
  semihosting: Split out semihost_sys_lseek
  semihosting: Split out semihost_sys_isatty
  semihosting: Split out semihost_sys_flen
  semihosting: Split out semihost_sys_remove
  semihosting: Split out semihost_sys_rename
  semihosting: Split out semihost_sys_system
  semihosting: Create semihost_sys_{stat,fstat}
  semihosting: Create semihost_sys_gettimeofday
  gdbstub: Widen gdb_syscall_complete_cb return value
  target/m68k: Eliminate m68k_semi_is_fseek
  target/m68k: Make semihosting system only
  target/m68k: Use guestfd.h to implement syscalls.
  target/m68k: Do semihosting call as a normal helper
  target/m68k: Enable semihosting for non-coldfire
  target/m68k: Remove EXCP_HALT_INSN
  target/nios2: Eliminate nios2_semi_is_lseek
  target/nios2: Move nios2-semi.c to nios2_softmmu_ss
  target/nios2: Use guestfd.h to implement syscalls.
  target/nios2: Do semihosting call as a normal helper

 configs/targets/aarch64-linux-user.mak        |   1 +
 configs/targets/aarch64_be-linux-user.mak     |   1 +
 configs/targets/arm-linux-user.mak            |   1 +
 configs/targets/armeb-linux-user.mak          |   1 +
 configs/targets/riscv32-linux-user.mak        |   1 +
 configs/targets/riscv64-linux-user.mak        |   1 +
 include/exec/gdbstub.h                        |  43 +-
 include/exec/softmmu-semi.h                   | 101 --
 .../semihosting}/common-semi.h                |   2 +-
 include/semihosting/guestfd.h                 |  95 ++
 include/semihosting/softmmu-uaccess.h         |  59 ++
 target/arm/common-semi-target.h               |  62 ++
 target/m68k/cpu.h                             |   3 -
 target/m68k/helper.h                          |   1 +
 target/nios2/cpu.h                            |   3 -
 target/nios2/helper.h                         |   1 +
 target/riscv/common-semi-target.h             |  50 +
 gdbstub.c                                     |   7 +-
 linux-user/aarch64/cpu_loop.c                 |   2 +-
 linux-user/arm/cpu_loop.c                     |   2 +-
 linux-user/m68k/cpu_loop.c                    |   5 -
 linux-user/riscv/cpu_loop.c                   |   2 +-
 semihosting/arm-compat-semi.c                 | 955 ++++--------------
 semihosting/console.c                         |   7 +-
 semihosting/guestfd.c                         | 935 +++++++++++++++++
 semihosting/uaccess.c                         |  71 ++
 target/arm/helper.c                           |   4 +-
 target/arm/m_helper.c                         |   2 +-
 target/m68k/m68k-semi.c                       | 374 +------
 target/m68k/op_helper.c                       |  15 -
 target/m68k/translate.c                       |  38 +-
 target/mips/tcg/sysemu/mips-semi.c            |   2 +-
 target/nios2/helper.c                         |   7 -
 target/nios2/nios2-semi.c                     | 357 +------
 target/nios2/translate.c                      |   2 +-
 target/riscv/cpu_helper.c                     |   2 +-
 semihosting/meson.build                       |   5 +
 target/m68k/meson.build                       |   6 +-
 target/nios2/meson.build                      |   4 +-
 39 files changed, 1686 insertions(+), 1544 deletions(-)
 delete mode 100644 include/exec/softmmu-semi.h
 rename {semihosting => include/semihosting}/common-semi.h (96%)
 create mode 100644 include/semihosting/guestfd.h
 create mode 100644 include/semihosting/softmmu-uaccess.h
 create mode 100644 target/arm/common-semi-target.h
 create mode 100644 target/riscv/common-semi-target.h
 create mode 100644 semihosting/guestfd.c
 create mode 100644 semihosting/uaccess.c

Comments

Richard Henderson May 1, 2022, 7:02 a.m. UTC | #1 
On 4/30/22 06:28, Richard Henderson wrote:
>    target/m68k: Do semihosting call as a normal helper
>    target/nios2: Do semihosting call as a normal helper

There's a reason not to do this: locking of the iothread mutex, and being back in the main 
loop, where the vm will be stopped while we may wait for a reply from gdb.


r~