[Qemu-devel] [RFC PATCH-for-4.1? v2 0/5] semihosting: Build with CONFIG_SEMIHOSTING disabled

[Philippe Mathieu-Daudé]

Amusingly Miroslav and myself hit this issue at the same time.

Note now that "config-devices.h" exists (commit 6c22ea9d83) I could use
#include "config-devices.h" to implement Alex's suggestion to avoid a stub:
https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg03607.html

Some know (arch-specific) limitations are:

- MIPS ITU is accessed by coprocessor instr (ISA feature)
- MIPS timer is accessed by coprocessor instr (ISA feature)
- MIPS semihosting (ISA feature?)
- ARM semihosting (ISA feature?)
- ARMv7 NVIC (device)

This series attempt to fix this the most trivial way, adding
stubs for unreachable code.

Since v1: https://lists.gnu.org/archive/html/qemu-devel/2019-05/msg07267.html
- Always enable semihosting on linux-user

$ git backport-diff -u v1
Key:
[----] : patches are identical
[####] : number of functional differences between upstream/downstream patch
[down] : patch is downstream-only (new)
The flags [FC] indicate (F)unctional and (C)ontextual differences, respectively

001/5:[down] 'target/arm: Always enable CONFIG_SEMIHOSTING'
002/5:[down] 'target/mips: Always enable CONFIG_SEMIHOSTING'
003/5:[down] 'hw/semihosting: Allow this feature to be disabled'
004/5:[0004] [FC] 'target/arm: Add stubs to build with CONFIG_SEMIHOSTING 
disabled'
005/5:[0005] [FC] 'target/mips: Add stubs to build with CONFIG_SEMIHOSTING 
disabled'

Philippe Mathieu-Daudé (5):
  target/arm: Always enable CONFIG_SEMIHOSTING
  target/mips: Always enable CONFIG_SEMIHOSTING
  hw/semihosting: Allow this feature to be disabled
  target/arm: Add stubs to build with CONFIG_SEMIHOSTING disabled
  target/mips: Add stubs to build with CONFIG_SEMIHOSTING disabled

 default-configs/aarch64-linux-user-common.mak |  4 ++++
 default-configs/aarch64-linux-user.mak        |  2 ++
 default-configs/aarch64_be-linux-user.mak     |  2 ++
 default-configs/arm-linux-user-common.mak     |  4 ++++
 default-configs/arm-linux-user.mak            |  2 ++
 default-configs/arm-softmmu.mak               |  4 +++-
 default-configs/armeb-linux-user.mak          |  2 ++
 default-configs/mips-linux-user-common.mak    |  4 ++++
 default-configs/mips-linux-user.mak           |  2 ++
 default-configs/mips-softmmu-common.mak       |  2 +-
 default-configs/mips64-linux-user.mak         |  2 ++
 default-configs/mips64el-linux-user.mak       |  2 ++
 default-configs/mipsel-linux-user.mak         |  2 ++
 default-configs/mipsn32-linux-user.mak        |  2 ++
 default-configs/mipsn32el-linux-user.mak      |  2 ++
 hw/semihosting/Kconfig                        |  3 ++-
 target/arm/Makefile.objs                      |  3 ++-
 target/arm/arm-semi-stubs.c                   | 21 ++++++++++++++++++
 target/mips/Makefile.objs                     |  3 ++-
 target/mips/mips-semi-stubs.c                 | 22 +++++++++++++++++++
 20 files changed, 85 insertions(+), 5 deletions(-)
 create mode 100644 default-configs/aarch64-linux-user-common.mak
 create mode 100644 default-configs/arm-linux-user-common.mak
 create mode 100644 default-configs/mips-linux-user-common.mak
 create mode 100644 target/arm/arm-semi-stubs.c
 create mode 100644 target/mips/mips-semi-stubs.c

-- 
2.20.1