pussuw commented on code in PR #6303: URL: https://github.com/apache/incubator-nuttx/pull/6303#discussion_r879051413
########## arch/risc-v/src/mpfs/mpfs_shead.S: ########## @@ -0,0 +1,87 @@ +/**************************************************************************** + * arch/risc-v/src/mpfs/mpfs_shead.S + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. The + * ASF licenses this file to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance with the + * License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations + * under the License. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <nuttx/irq.h> + +#include "chip.h" +#include "mpfs_memorymap.h" +#include "riscv_internal.h" + +/**************************************************************************** + * Public Symbols + ****************************************************************************/ + + /* Imported symbols */ + + .extern __trap_vec + + .section .text + .global __start + +/**************************************************************************** + * Name: __start + * + * Description: + * Supervisor mode start function. + * + * Input Parameters: + * a0 - hartid + * + ****************************************************************************/ + +__start: + + /* Disable all interrupts in sie */ + + csrw sie, zero + csrw sip, zero + + /* Set the S-mode trap vector */ + + la t0, __trap_vec + csrw stvec, t0 + + /* Clear sscratch */ + + csrw sscratch, zero + csrw scause, zero + csrw sepc, zero + + /* initialize global pointer, global data */ + +.option push +.option norelax + la gp, __global_pointer$ +.option pop + + /* Make sure the writes to CSR stick before continuing */ + + fence + + /* Set stack pointer and jump to start */ + + la sp, MPFS_IDLESTACK_TOP + j __mpfs_start Review Comment: I did not write the original code. The start function can, and must not return. The jump-and-link and the nop loop is unnecessary -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@nuttx.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
