From 0a48860c27a8eb291bcc7616ea9eb073dc660cab Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Fri, 24 May 2019 10:46:08 -0400 Subject: add riscv64 architecture support Author: Alex Suykov Author: Aric Belsito Author: Drew DeVault Author: Michael Clark Author: Michael Forney Author: Stefan O'Rear This port has involved the work of many people over several years. I have tried to ensure that everyone with substantial contributions has been credited above; if any omissions are found they will be noted later in an update to the authors/contributors list in the COPYRIGHT file. The version committed here comes from the riscv/riscv-musl repo's commit 3fe7e2c75df78eef42dcdc352a55757729f451e2, with minor changes by me for issues found during final review: - a_ll/a_sc atomics are removed (according to the ISA spec, lr/sc are not safe to use in separate inline asm fragments) - a_cas[_p] is fixed to be a memory barrier - the call from the _start assembly into the C part of crt1/ldso is changed to allow for the possibility that the linker does not place them nearby each other. - DTP_OFFSET is defined correctly so that local-dynamic TLS works - reloc.h LDSO_ARCH logic is simplified and made explicit. - unused, non-functional crti/n asm files are removed. - an empty .sdata section is added to crt1 so that the __global_pointer reference is resolvable. - indentation style errors in some asm files are fixed. --- src/thread/riscv64/clone.s | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100644 src/thread/riscv64/clone.s (limited to 'src/thread/riscv64/clone.s') diff --git a/src/thread/riscv64/clone.s b/src/thread/riscv64/clone.s new file mode 100644 index 00000000..db908248 --- /dev/null +++ b/src/thread/riscv64/clone.s @@ -0,0 +1,34 @@ +# __clone(func, stack, flags, arg, ptid, tls, ctid) +# a0, a1, a2, a3, a4, a5, a6 + +# syscall(SYS_clone, flags, stack, ptid, tls, ctid) +# a7 a0, a1, a2, a3, a4 + +.global __clone +.type __clone, %function +__clone: + # Save func and arg to stack + addi a1, a1, -16 + sd a0, 0(a1) + sd a3, 8(a1) + + # Call SYS_clone + mv a0, a2 + mv a2, a4 + mv a3, a5 + mv a4, a6 + li a7, 220 # SYS_clone + ecall + + beqz a0, 1f + # Parent + ret + + # Child +1: ld a1, 0(sp) + ld a0, 8(sp) + jalr a1 + + # Exit + li a7, 93 # SYS_exit + ecall -- cgit v1.2.1