diff options
Diffstat (limited to 'model')
| -rw-r--r-- | model/riscv_fetch_rvfi.sail | 50 |
1 files changed, 31 insertions, 19 deletions
diff --git a/model/riscv_fetch_rvfi.sail b/model/riscv_fetch_rvfi.sail index 50251e3..0f2ed4b 100644 --- a/model/riscv_fetch_rvfi.sail +++ b/model/riscv_fetch_rvfi.sail @@ -1,21 +1,33 @@ -function fetch() -> FetchResult = - /* check for legal PC */ - if (PC[0] != bitzero | (PC[1] != bitzero & (~ (haveRVC())))) - then F_Error(E_Fetch_Addr_Align(), PC) - else { - let i = rvfi_instruction.rvfi_insn(); - rvfi_exec->rvfi_order() = minstret; - rvfi_exec->rvfi_pc_rdata() = EXTZ(get_arch_pc()); - rvfi_exec->rvfi_insn() = EXTZ(i); +function fetch() -> FetchResult = { + rvfi_exec->rvfi_order() = minstret; + rvfi_exec->rvfi_pc_rdata() = EXTZ(get_arch_pc()); - /* TODO: should we write these even if they're not really registers? */ - rvfi_exec->rvfi_rs1_data() = EXTZ(X(i[19 .. 15])); - rvfi_exec->rvfi_rs2_data() = EXTZ(X(i[24 .. 20])); - rvfi_exec->rvfi_rs1_addr() = sail_zero_extend(i[19 .. 15],8); - rvfi_exec->rvfi_rs2_addr() = sail_zero_extend(i[24 .. 20],8); - - if (i[1 .. 0] == 0b11) - then F_Base(i) - else F_RVC(i[15 .. 0]) + /* First allow extensions to check pc */ + match ext_fetch_check_pc(PC, PC) { + Ext_FetchAddr_Error(e) => F_Ext_Error(e), + Ext_FetchAddr_OK(use_pc) => { + /* then check PC alignment */ + if (use_pc[0] != bitzero | (use_pc[1] != bitzero & (~ (haveRVC())))) + then F_Error(E_Fetch_Addr_Align(), PC) + else { + let i = rvfi_instruction.rvfi_insn(); + rvfi_exec->rvfi_insn() = EXTZ(i); + /* TODO: should we write these even if they're not really registers? */ + rvfi_exec->rvfi_rs1_data() = EXTZ(X(i[19 .. 15])); + rvfi_exec->rvfi_rs2_data() = EXTZ(X(i[24 .. 20])); + rvfi_exec->rvfi_rs1_addr() = sail_zero_extend(i[19 .. 15],8); + rvfi_exec->rvfi_rs2_addr() = sail_zero_extend(i[24 .. 20],8); + if (i[1 .. 0] != 0b11) + then F_RVC(i[15 .. 0]) + else { + /* fetch PC check for the next instruction granule */ + PC_hi : xlenbits = PC + 2; + match ext_fetch_check_pc(PC, PC_hi) { + Ext_FetchAddr_Error(e) => F_Ext_Error(e), + Ext_FetchAddr_OK(use_pc_hi) => F_Base(i) + } + } + } + } } - +} |