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/*
* Early initialization code for riscv
*
* Copyright 2015 Google Inc.
*
* 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; version 2 of
* the License.
*
* 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.
*/
#include <console/console.h>
#include <arch/exception.h>
#include <spike_util.h>
#include <string.h>
#define HART_ID 0
#define CONSOLE_PUT 1
#define SEND_DEVICE_REQUEST 2
#define RECEIVE_DEVICE_RESPONSE 3
#define SEND_IPI 4
#define CLEAR_IPI 5
#define SHUTDOWN 6
#define SET_TIMER 7
#define QUERY_MEMORY 8
int loopBreak2 = 1;
void handle_supervisor_call(trapframe *tf) {
uintptr_t call = tf->gpr[17];
uintptr_t arg0 = tf->gpr[10];
uintptr_t arg1 = tf->gpr[11];
uintptr_t returnValue;
switch(call) {
case HART_ID:
printk(BIOS_DEBUG, "Getting hart id...\n");
returnValue = mcall_hart_id();
break;
case CONSOLE_PUT:
returnValue = mcall_console_putchar(arg0);
break;
case SEND_DEVICE_REQUEST:
printk(BIOS_DEBUG, "Sending device request...\n");
returnValue = mcall_dev_req((sbi_device_message*) arg0);
break;
case RECEIVE_DEVICE_RESPONSE:
printk(BIOS_DEBUG, "Getting device response...\n");
returnValue = mcall_dev_resp();
break;
case SEND_IPI:
printk(BIOS_DEBUG, "Sending IPI...\n");
returnValue = mcall_send_ipi(arg0);
break;
case CLEAR_IPI:
printk(BIOS_DEBUG, "Clearing IPI...\n");
returnValue = mcall_clear_ipi();
break;
case SHUTDOWN:
printk(BIOS_DEBUG, "Shutting down...\n");
returnValue = mcall_shutdown();
break;
case SET_TIMER:
printk(BIOS_DEBUG, "Setting timer...\n");
returnValue = mcall_set_timer(arg0);
break;
case QUERY_MEMORY:
printk(BIOS_DEBUG, "Querying memory, CPU #%lld...\n", arg0);
returnValue = mcall_query_memory(arg0, (memory_block_info*) arg1);
break;
default:
printk(BIOS_DEBUG, "ERROR! Unrecognized system call\n");
returnValue = 0;
break; // note: system call we do not know how to handle
}
tf->gpr[10] = returnValue;
write_csr(mepc, read_csr(mepc) + 4);
asm volatile("j supervisor_call_return");
}
void trap_handler(trapframe *tf) {
write_csr(mscratch, tf);
int cause = 0;
void* epc = 0;
void* badAddr = 0;
// extract cause
asm("csrr t0, mcause");
asm("move %0, t0" : "=r"(cause));
// extract faulting Instruction pc
epc = (void*) tf->epc;
// extract bad address
asm("csrr t0, mbadaddr");
asm("move %0, t0" : "=r"(badAddr));
switch(cause) {
case 0:
printk(BIOS_DEBUG, "Trap: Instruction address misaligned\n");
break;
case 1:
printk(BIOS_DEBUG, "Trap: Instruction access fault\n");
printk(BIOS_DEBUG, "Bad instruction pc: %p\n", epc);
printk(BIOS_DEBUG, "Address: %p\n", badAddr);
break;
case 2:
printk(BIOS_DEBUG, "Trap: Illegal instruction\n");
printk(BIOS_DEBUG, "Bad instruction pc: %p\n", epc);
printk(BIOS_DEBUG, "Address: %p\n", badAddr);
break;
case 3:
printk(BIOS_DEBUG, "Trap: Breakpoint\n");
break;
case 4:
printk(BIOS_DEBUG, "Trap: Load address misaligned\n");
//handleMisalignedLoad(tf);
break;
case 5:
printk(BIOS_DEBUG, "Trap: Load access fault\n");
break;
case 6:
printk(BIOS_DEBUG, "Trap: Store address misaligned\n");
printk(BIOS_DEBUG, "Bad instruction pc: %p\n", epc);
printk(BIOS_DEBUG, "Store Address: %p\n", badAddr);
handle_misaligned_store(tf);
break;
case 7:
printk(BIOS_DEBUG, "Trap: Store access fault\n");
printk(BIOS_DEBUG, "Bad instruction pc: %p\n", epc);
printk(BIOS_DEBUG, "Store Address: %p\n", badAddr);
break;
case 8:
printk(BIOS_DEBUG, "Trap: Environment call from U-mode\n");
break;
case 9:
// Don't print so we make console putchar calls look the way they should
// printk(BIOS_DEBUG, "Trap: Environment call from S-mode\n");
handle_supervisor_call(tf);
break;
case 10:
printk(BIOS_DEBUG, "Trap: Environment call from H-mode\n");
break;
case 11:
printk(BIOS_DEBUG, "Trap: Environment call from M-mode\n");
break;
default:
printk(BIOS_DEBUG, "Trap: Unknown cause\n");
break;
}
printk(BIOS_DEBUG, "Stored ra: %p\n", (void*) tf->gpr[1]);
printk(BIOS_DEBUG, "Stored sp: %p\n", (void*) tf->gpr[2]);
printk(BIOS_DEBUG, "looping...\n");
while(1);
}
void handleMisalignedLoad(trapframe *tf) {
printk(BIOS_DEBUG, "Trapframe ptr: %p\n", tf);
printk(BIOS_DEBUG, "Stored sp: %p\n", (void*) tf->gpr[2]);
insn_t faultingInstruction = 0;
uintptr_t faultingInstructionAddr = tf->epc;
asm("move t0, %0" : /* No outputs */ : "r"(faultingInstructionAddr));
asm("lw t0, 0(t0)");
asm("move %0, t0" : "=r"(faultingInstruction));
printk(BIOS_DEBUG, "Faulting instruction: 0x%x\n", faultingInstruction);
insn_t widthMask = 0x7000;
insn_t memWidth = (faultingInstruction & widthMask) >> 12;
insn_t destMask = 0xF80;
insn_t destRegister = (faultingInstruction & destMask) >> 7;
printk(BIOS_DEBUG, "Width: 0x%x\n", memWidth);
if (memWidth == 3) {
// load double, handle the issue
void* badAddress = (void*) tf->badvaddr;
memcpy(&(tf->gpr[destRegister]), badAddress, 8);
} else {
// panic, this should not have happened
printk(BIOS_DEBUG, "Code should not reach this path, misaligned on a non-64 bit store/load\n");
while(1);
}
// return to where we came from
write_csr(mepc, read_csr(mepc) + 4);
asm volatile("j machine_call_return");
}
void handle_misaligned_store(trapframe *tf) {
printk(BIOS_DEBUG, "Trapframe ptr: %p\n", tf);
printk(BIOS_DEBUG, "Stored sp: %p\n", (void*) tf->gpr[2]);
insn_t faultingInstruction = 0;
uintptr_t faultingInstructionAddr = tf->epc;
asm("move t0, %0" : /* No outputs */ : "r"(faultingInstructionAddr));
asm("lw t0, 0(t0)");
asm("move %0, t0" : "=r"(faultingInstruction));
printk(BIOS_DEBUG, "Faulting instruction: 0x%x\n", faultingInstruction);
insn_t widthMask = 0x7000;
insn_t memWidth = (faultingInstruction & widthMask) >> 12;
insn_t srcMask = 0x1F00000;
insn_t srcRegister = (faultingInstruction & srcMask) >> 20;
printk(BIOS_DEBUG, "Width: 0x%x\n", memWidth);
if (memWidth == 3) {
// store double, handle the issue
void* badAddress = (void*) tf->badvaddr;
long valueToStore = tf->gpr[srcRegister];
memcpy(badAddress, &valueToStore, 8);
} else {
// panic, this should not have happened
printk(BIOS_DEBUG, "Code should not reach this path, misaligned on a non-64 bit store/load\n");
while(1);
}
// return to where we came from
write_csr(mepc, read_csr(mepc) + 4);
asm volatile("j machine_call_return");
}
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