From 12926c7ad6c437826625f9504a5b18aa31a8ad76 Mon Sep 17 00:00:00 2001 From: Andrew Waterman Date: Fri, 5 May 2017 16:27:08 -0700 Subject: [PATCH] UXL=SXL=MXL https://github.com/riscv/riscv-isa-manual/commit/326bec83de23f4d2daf24cfed6b5251748cad632 --- riscv/encoding.h | 3 +++ riscv/processor.cc | 19 +++++++++++++++---- 2 files changed, 18 insertions(+), 4 deletions(-) diff --git a/riscv/encoding.h b/riscv/encoding.h index 1463801..8ec1345 100644 --- a/riscv/encoding.h +++ b/riscv/encoding.h @@ -23,6 +23,8 @@ #define MSTATUS_TW 0x00200000 #define MSTATUS_TSR 0x00400000 #define MSTATUS32_SD 0x80000000 +#define MSTATUS_UXL 0x0000000300000000 +#define MSTATUS_SXL 0x0000000C00000000 #define MSTATUS64_SD 0x8000000000000000 #define SSTATUS_UIE 0x00000001 @@ -35,6 +37,7 @@ #define SSTATUS_SUM 0x00040000 #define SSTATUS_MXR 0x00080000 #define SSTATUS32_SD 0x80000000 +#define SSTATUS_UXL 0x0000000300000000 #define SSTATUS64_SD 0x8000000000000000 #define DCSR_XDEBUGVER (3U<<30) diff --git a/riscv/processor.cc b/riscv/processor.cc index ab5640e..664b44d 100644 --- a/riscv/processor.cc +++ b/riscv/processor.cc @@ -178,6 +178,15 @@ void processor_t::take_interrupt(reg_t pending_interrupts) throw trap_t(((reg_t)1 << (max_xlen-1)) | ctz(enabled_interrupts)); } +static int xlen_to_uxl(int xlen) +{ + if (xlen == 32) + return 1; + if (xlen == 64) + return 2; + abort(); +} + void processor_t::set_privilege(reg_t prv) { assert(prv <= PRV_M); @@ -300,7 +309,8 @@ void processor_t::set_csr(int which, reg_t val) reg_t mask = MSTATUS_SIE | MSTATUS_SPIE | MSTATUS_MIE | MSTATUS_MPIE | MSTATUS_SPP | MSTATUS_FS | MSTATUS_MPRV | MSTATUS_SUM | MSTATUS_MPP | MSTATUS_MXR | MSTATUS_TW | MSTATUS_TVM - | MSTATUS_TSR | (ext ? MSTATUS_XS : 0); + | MSTATUS_TSR | MSTATUS_UXL | MSTATUS_SXL | + (ext ? MSTATUS_XS : 0); state.mstatus = (state.mstatus & ~mask) | (val & mask); @@ -311,8 +321,9 @@ void processor_t::set_csr(int which, reg_t val) else state.mstatus = set_field(state.mstatus, MSTATUS64_SD, dirty); - // spike supports the notion of xlen < max_xlen, but current priv spec - // doesn't provide a mechanism to run RV32 software on an RV64 machine + state.mstatus = set_field(state.mstatus, MSTATUS_UXL, xlen_to_uxl(max_xlen)); + state.mstatus = set_field(state.mstatus, MSTATUS_SXL, xlen_to_uxl(max_xlen)); + // U-XLEN == S-XLEN == M-XLEN xlen = max_xlen; break; } @@ -513,7 +524,7 @@ reg_t processor_t::get_csr(int which) case CSR_MCOUNTEREN: return state.mcounteren; case CSR_SSTATUS: { reg_t mask = SSTATUS_SIE | SSTATUS_SPIE | SSTATUS_SPP | SSTATUS_FS - | SSTATUS_XS | SSTATUS_SUM; + | SSTATUS_XS | SSTATUS_SUM | SSTATUS_UXL; reg_t sstatus = state.mstatus & mask; if ((sstatus & SSTATUS_FS) == SSTATUS_FS || (sstatus & SSTATUS_XS) == SSTATUS_XS) -- 2.30.2