From 3c77f97eb0825f5808f4a3a01aa5cc2fcffd5ed4 Mon Sep 17 00:00:00 2001 From: Jim Wilson Date: Thu, 9 Aug 2018 13:35:24 -0700 Subject: [PATCH] RISC-V: Add native linux support. Add initial native support for riscv*-linux*. gdb/ * riscv-linux-nat.c: New file. --- gdb/ChangeLog | 1 + gdb/riscv-linux-nat.c | 280 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 281 insertions(+) create mode 100644 gdb/riscv-linux-nat.c diff --git a/gdb/ChangeLog b/gdb/ChangeLog index ae6bcebb048..40210bbd331 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,6 @@ 2018-08-09 Jim Wilson + * riscv-linux-nat.c: New file. * riscv-linux-tdep.c: New file. 2018-08-09 Andrew Burgess diff --git a/gdb/riscv-linux-nat.c b/gdb/riscv-linux-nat.c new file mode 100644 index 00000000000..3faa9f9c1f6 --- /dev/null +++ b/gdb/riscv-linux-nat.c @@ -0,0 +1,280 @@ +/* Native-dependent code for GNU/Linux RISC-V. + Copyright (C) 2018 Free Software Foundation, Inc. + + This file is part of GDB. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +#include "defs.h" +#include "regcache.h" +#include "gregset.h" +#include "linux-nat.h" +#include "elf.h" +#include "riscv-tdep.h" + +#include + +/* RISC-V Linux native additions to the default linux support. */ + +class riscv_linux_nat_target final : public linux_nat_target +{ +public: + /* Add our register access methods. */ + void fetch_registers (struct regcache *regcache, int regnum) override; + void store_registers (struct regcache *regcache, int regnum) override; +}; + +static riscv_linux_nat_target the_riscv_linux_nat_target; + +/* Copy general purpose register REGNUM (or all gp regs if REGNUM == -1) + from regset GREGS into REGCACHE. */ + +static void +supply_gregset_regnum (struct regcache *regcache, const prgregset_t *gregs, + int regnum) +{ + int i; + const elf_greg_t *regp = *gregs; + + if (regnum == -1) + { + /* We only support the integer registers and PC here. */ + for (i = RISCV_ZERO_REGNUM + 1; i < RISCV_PC_REGNUM; i++) + regcache->raw_supply (i, regp + i); + + /* GDB stores PC in reg 32. Linux kernel stores it in reg 0. */ + regcache->raw_supply (32, regp + 0); + + /* Fill the inaccessible zero register with zero. */ + regcache->raw_supply_zeroed (0); + } + else if (regnum == RISCV_ZERO_REGNUM) + regcache->raw_supply_zeroed (0); + else if (regnum > RISCV_ZERO_REGNUM && regnum < RISCV_PC_REGNUM) + regcache->raw_supply (regnum, regp + regnum); + else if (regnum == RISCV_PC_REGNUM) + regcache->raw_supply (32, regp + 0); +} + +/* Copy all general purpose registers from regset GREGS into REGCACHE. */ + +void +supply_gregset (struct regcache *regcache, const prgregset_t *gregs) +{ + supply_gregset_regnum (regcache, gregs, -1); +} + +/* Copy floating point register REGNUM (or all fp regs if REGNUM == -1) + from regset FPREGS into REGCACHE. */ + +static void +supply_fpregset_regnum (struct regcache *regcache, const prfpregset_t *fpregs, + int regnum) +{ + int i; + + if (regnum == -1) + { + /* We only support the FP registers and FCSR here. */ + for (i = RISCV_FIRST_FP_REGNUM; i <= RISCV_LAST_FP_REGNUM; i++) + regcache->raw_supply (i, &fpregs->__d.__f[i - RISCV_FIRST_FP_REGNUM]); + + regcache->raw_supply (RISCV_CSR_FCSR_REGNUM, &fpregs->__d.__fcsr); + } + else if (regnum >= RISCV_FIRST_FP_REGNUM && regnum <= RISCV_LAST_FP_REGNUM) + regcache->raw_supply (regnum, + &fpregs->__d.__f[regnum - RISCV_FIRST_FP_REGNUM]); + else if (regnum == RISCV_CSR_FCSR_REGNUM) + regcache->raw_supply (RISCV_CSR_FCSR_REGNUM, &fpregs->__d.__fcsr); +} + +/* Copy all floating point registers from regset FPREGS into REGCACHE. */ + +void +supply_fpregset (struct regcache *regcache, const prfpregset_t *fpregs) +{ + supply_fpregset_regnum (regcache, fpregs, -1); +} + +/* Copy general purpose register REGNUM (or all gp regs if REGNUM == -1) + from REGCACHE into regset GREGS. */ + +void +fill_gregset (const struct regcache *regcache, prgregset_t *gregs, int regnum) +{ + elf_greg_t *regp = *gregs; + + if (regnum == -1) + { + /* We only support the integer registers and PC here. */ + for (int i = RISCV_ZERO_REGNUM + 1; i < RISCV_PC_REGNUM; i++) + regcache->raw_collect (i, regp + i); + + regcache->raw_collect (32, regp + 0); + } + else if (regnum == RISCV_ZERO_REGNUM) + /* Nothing to do here. */ + ; + else if (regnum > RISCV_ZERO_REGNUM && regnum < RISCV_PC_REGNUM) + regcache->raw_collect (regnum, regp + regnum); + else if (regnum == RISCV_PC_REGNUM) + regcache->raw_collect (32, regp + 0); +} + +/* Copy floating point register REGNUM (or all fp regs if REGNUM == -1) + from REGCACHE into regset FPREGS. */ + +void +fill_fpregset (const struct regcache *regcache, prfpregset_t *fpregs, + int regnum) +{ + if (regnum == -1) + { + /* We only support the FP registers and FCSR here. */ + for (int i = RISCV_FIRST_FP_REGNUM; i <= RISCV_LAST_FP_REGNUM; i++) + regcache->raw_collect (i, &fpregs->__d.__f[i - RISCV_FIRST_FP_REGNUM]); + + regcache->raw_collect (RISCV_CSR_FCSR_REGNUM, &fpregs->__d.__fcsr); + } + else if (regnum >= RISCV_FIRST_FP_REGNUM && regnum <= RISCV_LAST_FP_REGNUM) + regcache->raw_collect (regnum, + &fpregs->__d.__f[regnum - RISCV_FIRST_FP_REGNUM]); + else if (regnum == RISCV_CSR_FCSR_REGNUM) + regcache->raw_collect (RISCV_CSR_FCSR_REGNUM, &fpregs->__d.__fcsr); +} + +/* Fetch REGNUM (or all registers if REGNUM == -1) from the target + into REGCACHE using PTRACE_GETREGSET. */ + +void +riscv_linux_nat_target::fetch_registers (struct regcache *regcache, int regnum) +{ + int tid; + + tid = get_ptrace_pid (regcache->ptid()); + + if ((regnum >= RISCV_ZERO_REGNUM && regnum <= RISCV_PC_REGNUM) + || (regnum == -1)) + { + struct iovec iov; + elf_gregset_t regs; + + iov.iov_base = ®s; + iov.iov_len = sizeof (regs); + + if (ptrace (PTRACE_GETREGSET, tid, NT_PRSTATUS, + (PTRACE_TYPE_ARG3) &iov) == -1) + perror_with_name (_("Couldn't get registers")); + else + supply_gregset_regnum (regcache, ®s, regnum); + } + + if ((regnum >= RISCV_FIRST_FP_REGNUM + && regnum <= RISCV_LAST_FP_REGNUM) + || (regnum == RISCV_CSR_FCSR_REGNUM) + || (regnum == -1)) + { + struct iovec iov; + elf_fpregset_t regs; + + iov.iov_base = ®s; + iov.iov_len = sizeof (regs); + + if (ptrace (PTRACE_GETREGSET, tid, NT_PRFPREG, + (PTRACE_TYPE_ARG3) &iov) == -1) + perror_with_name (_("Couldn't get registers")); + else + supply_fpregset_regnum (regcache, ®s, regnum); + } + + if ((regnum == RISCV_CSR_MISA_REGNUM) + || (regnum == -1)) + { + /* TODO: Need to add a ptrace call for this. */ + regcache->raw_supply_zeroed (regnum); + } + + /* Access to other CSRs has potential security issues, don't support them for + now. */ +} + +/* Store REGNUM (or all registers if REGNUM == -1) to the target + from REGCACHE using PTRACE_SETREGSET. */ + +void +riscv_linux_nat_target::store_registers (struct regcache *regcache, int regnum) +{ + int tid; + + tid = get_ptrace_pid (regcache->ptid ()); + + if ((regnum >= RISCV_ZERO_REGNUM && regnum <= RISCV_PC_REGNUM) + || (regnum == -1)) + { + struct iovec iov; + elf_gregset_t regs; + + iov.iov_base = ®s; + iov.iov_len = sizeof (regs); + + if (ptrace (PTRACE_GETREGSET, tid, NT_PRSTATUS, + (PTRACE_TYPE_ARG3) &iov) == -1) + perror_with_name (_("Couldn't get registers")); + else + { + fill_gregset (regcache, ®s, regnum); + + if (ptrace (PTRACE_SETREGSET, tid, NT_PRSTATUS, + (PTRACE_TYPE_ARG3) &iov) == -1) + perror_with_name (_("Couldn't set registers")); + } + } + + if ((regnum >= RISCV_FIRST_FP_REGNUM + && regnum <= RISCV_LAST_FP_REGNUM) + || (regnum == RISCV_CSR_FCSR_REGNUM) + || (regnum == -1)) + { + struct iovec iov; + elf_fpregset_t regs; + + iov.iov_base = ®s; + iov.iov_len = sizeof (regs); + + if (ptrace (PTRACE_GETREGSET, tid, NT_PRFPREG, + (PTRACE_TYPE_ARG3) &iov) == -1) + perror_with_name (_("Couldn't get registers")); + else + { + fill_fpregset (regcache, ®s, regnum); + + if (ptrace (PTRACE_SETREGSET, tid, NT_PRFPREG, + (PTRACE_TYPE_ARG3) &iov) == -1) + perror_with_name (_("Couldn't set registers")); + } + } + + /* Access to CSRs has potential security issues, don't support them for + now. */ +} + +/* Initialize RISC-V Linux native support. */ + +void +_initialize_riscv_linux_nat (void) +{ + /* Register the target. */ + linux_target = &the_riscv_linux_nat_target; + add_inf_child_target (&the_riscv_linux_nat_target); +} -- 2.30.2