From df6794374bae455b3ad65dbc1ea0436b764d24e8 Mon Sep 17 00:00:00 2001 From: Tim Newsome Date: Tue, 10 May 2016 13:22:31 -0700 Subject: [PATCH] Exceptions in Debug Mode don't update any regs. --- riscv/gdbserver.cc | 86 ++++++++++++++-------------------------------- riscv/gdbserver.h | 6 ++-- riscv/processor.cc | 14 ++++---- 3 files changed, 35 insertions(+), 71 deletions(-) diff --git a/riscv/gdbserver.cc b/riscv/gdbserver.cc index 7c94615..33a24e9 100644 --- a/riscv/gdbserver.cc +++ b/riscv/gdbserver.cc @@ -279,33 +279,24 @@ class halt_op_t : public operation_t gs.write_debug_ram(0, csrsi(CSR_DCSR, DCSR_HALT)); gs.write_debug_ram(1, csrr(S0, CSR_DPC)); gs.write_debug_ram(2, sd(S0, 0, (uint16_t) DEBUG_RAM_START)); - gs.write_debug_ram(3, csrr(S0, CSR_MBADADDR)); + gs.write_debug_ram(3, csrr(S0, CSR_MSTATUS)); gs.write_debug_ram(4, sd(S0, 0, (uint16_t) DEBUG_RAM_START + 8)); gs.write_debug_ram(5, jal(0, (uint32_t) (DEBUG_ROM_RESUME - (DEBUG_RAM_START + 4*5)))); gs.set_interrupt(0); - // We could read mcause here as well, but only on 64-bit targets. I'm - // trying to keep The patterns here usable for 32-bit ISAs as well. (On a - // 32-bit ISA 8 words are required, while the minimum Debug RAM size is 7 - // words.) + // We could read more registers here, but only on 64-bit targets. I'm + // trying to keep The patterns here usable for 32-bit ISAs as well. return false; case 1: - gs.saved_dpc = ((uint64_t) gs.read_debug_ram(1) << 32) | gs.read_debug_ram(0); - gs.saved_mbadaddr = ((uint64_t) gs.read_debug_ram(3) << 32) | gs.read_debug_ram(2); - - gs.write_debug_ram(0, csrr(S0, CSR_MCAUSE)); - gs.write_debug_ram(1, sd(S0, 0, (uint16_t) DEBUG_RAM_START + 0)); - gs.write_debug_ram(2, csrr(S0, CSR_MSTATUS)); - gs.write_debug_ram(3, sd(S0, 0, (uint16_t) DEBUG_RAM_START + 8)); - gs.write_debug_ram(4, csrr(S0, CSR_DCSR)); - gs.write_debug_ram(5, sd(S0, 0, (uint16_t) DEBUG_RAM_START + 16)); - gs.write_debug_ram(6, jal(0, (uint32_t) (DEBUG_ROM_RESUME - (DEBUG_RAM_START + 4*6)))); + gs.dpc = ((uint64_t) gs.read_debug_ram(1) << 32) | gs.read_debug_ram(0); + gs.mstatus = ((uint64_t) gs.read_debug_ram(3) << 32) | gs.read_debug_ram(2); + gs.write_debug_ram(0, csrr(S0, CSR_DCSR)); + gs.write_debug_ram(1, sd(S0, 0, (uint16_t) DEBUG_RAM_START + 16)); + gs.write_debug_ram(2, jal(0, (uint32_t) (DEBUG_ROM_RESUME - (DEBUG_RAM_START + 4*6)))); gs.set_interrupt(0); return false; case 2: - gs.saved_mcause = ((uint64_t) gs.read_debug_ram(1) << 32) | gs.read_debug_ram(0); - gs.saved_mstatus = ((uint64_t) gs.read_debug_ram(3) << 32) | gs.read_debug_ram(2); gs.dcsr = ((uint64_t) gs.read_debug_ram(5) << 32) | gs.read_debug_ram(4); gs.sptbr_valid = false; @@ -360,35 +351,24 @@ class continue_op_t : public operation_t } else { gs.write_debug_ram(2, jal(0, (uint32_t) (DEBUG_ROM_RESUME - (DEBUG_RAM_START + 4*2)))); } - gs.write_debug_ram(4, gs.saved_dpc); - gs.write_debug_ram(5, gs.saved_dpc >> 32); + gs.write_debug_ram(4, gs.dpc); + gs.write_debug_ram(5, gs.dpc >> 32); gs.set_interrupt(0); return false; case 1: gs.write_debug_ram(0, ld(S0, 0, (uint16_t) DEBUG_RAM_START+16)); - gs.write_debug_ram(1, csrw(S0, CSR_MBADADDR)); + gs.write_debug_ram(1, csrw(S0, CSR_MSTATUS)); gs.write_debug_ram(2, jal(0, (uint32_t) (DEBUG_ROM_RESUME - (DEBUG_RAM_START + 4*2)))); - gs.write_debug_ram(4, gs.saved_mbadaddr); - gs.write_debug_ram(5, gs.saved_mbadaddr >> 32); + gs.write_debug_ram(4, gs.mstatus); + gs.write_debug_ram(5, gs.mstatus >> 32); gs.set_interrupt(0); return false; case 2: - gs.write_debug_ram(0, ld(S0, 0, (uint16_t) DEBUG_RAM_START+16)); - gs.write_debug_ram(1, csrw(S0, CSR_MSTATUS)); + gs.write_debug_ram(0, lw(S0, 0, (uint16_t) DEBUG_RAM_START+16)); + gs.write_debug_ram(1, csrw(S0, CSR_DCSR)); gs.write_debug_ram(2, jal(0, (uint32_t) (DEBUG_ROM_RESUME - (DEBUG_RAM_START + 4*2)))); - gs.write_debug_ram(4, gs.saved_mstatus); - gs.write_debug_ram(5, gs.saved_mstatus >> 32); - gs.set_interrupt(0); - return false; - - case 3: - gs.write_debug_ram(0, ld(S0, 0, (uint16_t) DEBUG_RAM_START+24)); - gs.write_debug_ram(1, csrw(S0, CSR_MCAUSE)); - gs.write_debug_ram(2, lw(S0, 0, (uint16_t) DEBUG_RAM_START+20)); - gs.write_debug_ram(3, csrw(S0, CSR_DCSR)); - gs.write_debug_ram(4, jal(0, (uint32_t) (DEBUG_ROM_RESUME - (DEBUG_RAM_START + 4*4)))); reg_t dcsr = set_field(gs.dcsr, DCSR_HALT, 0); dcsr = set_field(dcsr, DCSR_STEP, single_step); @@ -397,10 +377,8 @@ class continue_op_t : public operation_t dcsr = set_field(dcsr, DCSR_EBREAKH, 1); dcsr = set_field(dcsr, DCSR_EBREAKS, 1); dcsr = set_field(dcsr, DCSR_EBREAKU, 1); - gs.write_debug_ram(5, dcsr); + gs.write_debug_ram(4, dcsr); - gs.write_debug_ram(6, gs.saved_mcause); - gs.write_debug_ram(7, gs.saved_mcause >> 32); gs.set_interrupt(0); return true; } @@ -484,23 +462,13 @@ class register_read_op_t : public operation_t // send(p->state.XPR[reg - REG_XPR0]); } else if (reg == REG_PC) { gs.start_packet(); - gs.send(gs.saved_dpc); + gs.send(gs.dpc); gs.end_packet(); return true; } else if (reg >= REG_FPR0 && reg <= REG_FPR31) { // send(p->state.FPR[reg - REG_FPR0]); gs.write_debug_ram(0, fsd(reg - REG_FPR0, 0, (uint16_t) DEBUG_RAM_START + 16)); gs.write_debug_ram(1, jal(0, (uint32_t) (DEBUG_ROM_RESUME - (DEBUG_RAM_START + 4*1)))); - } else if (reg == REG_CSR0 + CSR_MBADADDR) { - gs.start_packet(); - gs.send(gs.saved_mbadaddr); - gs.end_packet(); - return true; - } else if (reg == REG_CSR0 + CSR_MCAUSE) { - gs.start_packet(); - gs.send(gs.saved_mcause); - gs.end_packet(); - return true; } else if (reg >= REG_CSR0 && reg <= REG_CSR4095) { gs.write_debug_ram(0, csrr(S0, reg - REG_CSR0)); gs.write_debug_ram(1, sd(S0, 0, (uint16_t) DEBUG_RAM_START + 16)); @@ -550,21 +518,19 @@ class register_write_op_t : public operation_t gs.write_debug_ram(1, addi(reg, S0, 0)); gs.write_debug_ram(2, jal(0, (uint32_t) (DEBUG_ROM_RESUME - (DEBUG_RAM_START + 4*2)))); } else if (reg == REG_PC) { - gs.saved_dpc = value; + gs.dpc = value; return true; } else if (reg >= REG_FPR0 && reg <= REG_FPR31) { // send(p->state.FPR[reg - REG_FPR0]); gs.write_debug_ram(0, fld(reg - REG_FPR0, 0, (uint16_t) DEBUG_RAM_START + 16)); gs.write_debug_ram(1, jal(0, (uint32_t) (DEBUG_ROM_RESUME - (DEBUG_RAM_START + 4*1)))); - } else if (reg == REG_CSR0 + CSR_MBADADDR) { - gs.saved_mbadaddr = value; - return true; - } else if (reg == REG_CSR0 + CSR_MCAUSE) { - gs.saved_mcause = value; - return true; } else if (reg >= REG_CSR0 && reg <= REG_CSR4095) { gs.write_debug_ram(1, csrw(S0, reg - REG_CSR0)); gs.write_debug_ram(2, jal(0, (uint32_t) (DEBUG_ROM_RESUME - (DEBUG_RAM_START + 4*2)))); + if (reg == REG_CSR0 + CSR_SPTBR) { + gs.sptbr = value; + gs.sptbr_valid = true; + } } else { gs.send_packet("E02"); return true; @@ -1014,8 +980,8 @@ reg_t gdbserver_t::translate(reg_t vaddr) unsigned int gdbserver_t::privilege_mode() { unsigned int mode = get_field(dcsr, DCSR_PRV); - if (get_field(saved_mstatus, MSTATUS_MPRV)) - mode = get_field(saved_mstatus, MSTATUS_MPP); + if (get_field(mstatus, MSTATUS_MPRV)) + mode = get_field(mstatus, MSTATUS_MPP); return mode; } @@ -1024,7 +990,7 @@ unsigned int gdbserver_t::virtual_memory() unsigned int mode = privilege_mode(); if (mode == PRV_M) return VM_MBARE; - return get_field(saved_mstatus, MSTATUS_VM); + return get_field(mstatus, MSTATUS_VM); } void gdbserver_t::write_debug_ram(unsigned int index, uint32_t value) @@ -1371,7 +1337,7 @@ void gdbserver_t::handle_continue(const std::vector &packet) processor_t *p = sim->get_core(0); if (packet[2] != '#') { std::vector::const_iterator iter = packet.begin() + 2; - saved_dpc = consume_hex_number(iter, packet.end()); + dpc = consume_hex_number(iter, packet.end()); if (*iter != '#') return send_packet("E30"); } diff --git a/riscv/gdbserver.h b/riscv/gdbserver.h index 6211146..6e94ed2 100644 --- a/riscv/gdbserver.h +++ b/riscv/gdbserver.h @@ -135,11 +135,9 @@ public: // Members that ought to be privated, but that we'd really like to access // from operation classes. - reg_t saved_dpc; - reg_t saved_mbadaddr; - reg_t saved_mcause; - reg_t saved_mstatus; + reg_t dpc; reg_t dcsr; + reg_t mstatus; reg_t sptbr; bool sptbr_valid; bool fence_i_required; diff --git a/riscv/processor.cc b/riscv/processor.cc index 25b6144..3b5b313 100644 --- a/riscv/processor.cc +++ b/riscv/processor.cc @@ -226,6 +226,11 @@ void processor_t::take_trap(trap_t& t, reg_t epc) return; } + if (state.dcsr.cause) { + state.pc = DEBUG_ROM_EXCEPTION; + return; + } + // by default, trap to M-mode, unless delegated to S-mode reg_t bit = t.cause(); reg_t deleg = state.medeleg; @@ -246,13 +251,8 @@ void processor_t::take_trap(trap_t& t, reg_t epc) set_csr(CSR_MSTATUS, s); set_privilege(PRV_S); } else { - if (state.dcsr.cause) { - state.pc = DEBUG_ROM_EXCEPTION; - state.dpc = epc; - } else { - state.pc = state.mtvec; - state.mepc = epc; - } + state.pc = state.mtvec; + state.mepc = epc; state.mcause = t.cause(); if (t.has_badaddr()) state.mbadaddr = t.get_badaddr(); -- 2.30.2