[PATCH v8 0/2] Minimal build for RISCV

[Connor Davis <connojdavis@xxxxxxxxx>]

Hi all,

This series introduces a minimal build for RISCV. It is based on Bobby's
previous work from last year[0] rebased onto current Xen.

This series provides the patches necessary to get a minimal build
working. The build is "minimal" in the sense that it only supports
building TARGET=riscv64/head.o. The arch/riscv/riscv64/head.S is just
a simple while(1).

The first patch is a mod to non-RISCV bits that enable building a
config with !CONFIG_HAS_NS16550.

The second patch adds the make/Kconfig boilerplate alongside head.S and
asm-riscv/config.h (head.S references ENTRY that is defined in
asm-riscv/config.h).

[0] 
https://lore.kernel.org/xen-devel/cover.1579615303.git.bobbyeshleman@xxxxxxxxx/

Thanks,
Connor

--
Changes since v7:
  - Default to y for RISCV_ISA_C Kconfig option (i.e. build Xen with
    compressed instructions by default)
  - Added Alistair to MAINTAINERS

Changes since v6:
  - Make sure patch versions are consistent

Changes since v5:
  - Added missing A-by from Jan to patch 1

Changes since v4:
  - Dropped patches 2 and 4 as these have been applied
  - Moved arch/riscv/head.S to arch/riscv/riscv64/head.S for consistency
    with ARM.
  - Added Bob and myself to MAINTAINERS

Changes since v3:
  - Dropped "xen: Fix build when !CONFIG_GRANT_TABLE" since this was
    applied by Jan
  - Adjusted Kconfig condition for building NS16550
  - Use bool rather than bool_t
  - Removed riscv memory map, as this should probably be done later once
    the frametable size is figured out
  - Consolidated 64-bit #defines in asm-riscv/config.h
  - Renamed riscv64_defconfig to tiny64_defconfig, added CONFIG_DEBUG
    and CONFIG_DEBUG_INFO
  - Fixed logic/alignment/whitespace issues in Kconfig files
  - Use upstream archlinux riscv64 cross-compiler packages instead of
    custom built toolchain in docker container

Changes since v2:
  - Reduced number of riscv files added to ease review

Changes since v1:
  - Dropped "xen/sched: Fix build when NR_CPUS == 1" since this was
    fixed for 4.15
  - Moved #ifdef-ary around iommu_enabled to iommu.h
  - Moved struct grant_table declaration above ifdef CONFIG_GRANT_TABLE

--
Connor Davis (2):
  xen/char: Default HAS_NS16550 to y only for X86 and ARM
  xen: Add files needed for minimal riscv build

 MAINTAINERS                             |  9 +++++
 config/riscv64.mk                       |  5 +++
 xen/Makefile                            |  8 +++--
 xen/arch/riscv/Kconfig                  | 48 +++++++++++++++++++++++++
 xen/arch/riscv/Kconfig.debug            |  0
 xen/arch/riscv/Makefile                 |  2 ++
 xen/arch/riscv/Rules.mk                 |  0
 xen/arch/riscv/arch.mk                  | 14 ++++++++
 xen/arch/riscv/configs/tiny64_defconfig | 13 +++++++
 xen/arch/riscv/riscv64/asm-offsets.c    |  0
 xen/arch/riscv/riscv64/head.S           |  6 ++++
 xen/drivers/char/Kconfig                |  1 +
 xen/include/asm-riscv/config.h          | 47 ++++++++++++++++++++++++
 13 files changed, 151 insertions(+), 2 deletions(-)
 create mode 100644 config/riscv64.mk
 create mode 100644 xen/arch/riscv/Kconfig
 create mode 100644 xen/arch/riscv/Kconfig.debug
 create mode 100644 xen/arch/riscv/Makefile
 create mode 100644 xen/arch/riscv/Rules.mk
 create mode 100644 xen/arch/riscv/arch.mk
 create mode 100644 xen/arch/riscv/configs/tiny64_defconfig
 create mode 100644 xen/arch/riscv/riscv64/asm-offsets.c
 create mode 100644 xen/arch/riscv/riscv64/head.S
 create mode 100644 xen/include/asm-riscv/config.h

-- 
2.31.1