Greetings. Big endian support for RISC-V was added in binutils 2.36, released yesterday. This patch set adds support to gcc for exploting this mode.
Please note that in addition to these patches, an pull of config.sub from upstreams is needed. In adding the big endian support, I had the following goals: * Apply default endianness based on triplet * Allow endianness override with -mbig-endian / -mlittle-endian * Retain compatibility with older binutils for use cases which do not explicitly invoke new functionality (i.e. specify new command line options or target a new triplet) Based on these goals, this is what I did _not_ do: * Implicitly pass default endianness as -mbig-endian / -mlittle-endian to gas, since older binutils targeting little endian will not understand -mlittle-endian. Instead assume gas has the same default as gcc. If -mbig-endian or -mlittle-endian is explicitly given, it is passed on to gas since this use is under the discretion of the user. (This means that DRIVER_SELF_SPECS can not be used to set the default.) * Configure multilib for big/little endian, since that would require newest binutils when building for a little endian target, due to the requirement to build libgcc et al as big endian. For ld, I think it would have been ok to pass -EL to older binutils, but for symmetry reasons I keep the ld commandline identical to before when default is little endian, and change the '-melf64lriscv' into '-melf64briscv' when the default is big endian. This has the desired effect of informing ld what the default endianness is, and still allows it to be overridden with -EB and -EL (translated from -mbig-endian and -mlittle-endian). // Marcus gcc/common/config/riscv/riscv-common.c | 5 +++++ gcc/config.gcc | 15 +++++++++++++++ gcc/config/riscv/elf.h | 4 +++- gcc/config/riscv/freebsd.h | 4 +++- gcc/config/riscv/linux.h | 4 +++- gcc/config/riscv/riscv.c | 5 +++++ gcc/config/riscv/riscv.h | 12 ++++++++++-- gcc/config/riscv/riscv.opt | 8 ++++++++ 8 files changed, 52 insertions(+), 5 deletions(-)
