andrey/osblog
1
0
Fork 0
mirror of https://github.com/sgmarz/osblog.git synced 2024-11-24 02:16:19 +04:00
Code Issues Projects Releases Wiki Activity

Added Registers to CPU so we don't have to hardcode the register number. This makes it easier to read and figure out what's happening

Browse Source
This commit is contained in:
Stephen Marz 2020-05-15 12:48:05 -04:00
parent adcc06d07a
commit c649947707
4 changed files with 65 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
risc_v/src/cpu.rs
View File

@ -27,6 +27,42 @@ pub enum CpuMode {
Machine = 3,
}
#[repr(usize)]
pub enum Registers {
Zero = 0,
Ra,
Sp,
Gp,
Tp,
T0,
T1,
T2,
S0,
S1,
A0, /* 10 */
A1,
A2,
A3,
A4,
A5,
A6,
A7,
S2,
S3,
S4, /* 20 */
S5,
S6,
S7,
S8,
S9,
S10,
S11,
T3,
T4,
T5, /* 30 */
T6
}
/// The trap frame is set into a structure
/// and packed into each hart's mscratch register.
/// This allows for quick reference and full

5
risc_v/src/elf.rs
View File

@ -10,7 +10,8 @@ use crate::{buffer::Buffer,
satp_fence_asid,
CpuMode,
SatpMode,
TrapFrame},
TrapFrame,
Registers},
page::{map, zalloc, EntryBits, Table, PAGE_SIZE},
process::{Process,
ProcessData,
@ -243,7 +244,7 @@ impl File {
(*my_proc.frame).pc = elf_fl.header.entry_addr;
// Stack pointer. The stack starts at the bottom and works its
// way up, so we have to set the stack pointer to the bottom.
(*my_proc.frame).regs[2] =
(*my_proc.frame).regs[Registers::Sp as usize] =
STACK_ADDR as usize + STACK_PAGES * PAGE_SIZE;
// USER MODE! This is how we set what'll go into mstatus when we
// run the process.

15
risc_v/src/process.rs
View File

@ -8,7 +8,8 @@ use crate::{cpu::{build_satp,
satp_fence_asid,
CpuMode,
SatpMode,
TrapFrame},
TrapFrame,
Registers},
page::{alloc,
dealloc,
map,
@ -268,8 +269,8 @@ pub fn add_kernel_process(func: fn()) -> u16 {
// 1 is the return address register. This makes it so we
// don't have to do syscall_exit() when a kernel process
// finishes.
(*ret_proc.frame).regs[1] = ra_delete_proc as usize;
(*ret_proc.frame).regs[2] =
(*ret_proc.frame).regs[Registers::Ra as usize] = ra_delete_proc as usize;
(*ret_proc.frame).regs[Registers::Sp as usize] =
ret_proc.stack as usize + STACK_PAGES * 4096;
(*ret_proc.frame).mode = CpuMode::Machine as usize;
(*ret_proc.frame).pid = ret_proc.pid as usize;
@ -350,12 +351,12 @@ pub fn add_kernel_process_args(func: fn(args_ptr: usize), args: usize) -> u16 {
// bottom of the memory and far away from heap allocations.
unsafe {
(*ret_proc.frame).pc = func_vaddr;
(*ret_proc.frame).regs[10] = args;
(*ret_proc.frame).regs[Registers::A0 as usize] = args;
// 1 is the return address register. This makes it so we
// don't have to do syscall_exit() when a kernel process
// finishes.
(*ret_proc.frame).regs[1] = ra_delete_proc as usize;
(*ret_proc.frame).regs[2] =
(*ret_proc.frame).regs[Registers::Ra as usize] = ra_delete_proc as usize;
(*ret_proc.frame).regs[Registers::Sp as usize] =
ret_proc.stack as usize + STACK_PAGES * 4096;
(*ret_proc.frame).mode = CpuMode::Machine as usize;
(*ret_proc.frame).pid = ret_proc.pid as usize;
@ -519,7 +520,7 @@ impl Process {
let saddr = ret_proc.stack as usize;
unsafe {
(*ret_proc.frame).pc = func_vaddr;
(*ret_proc.frame).regs[2] =
(*ret_proc.frame).regs[Registers::Sp as usize] =
STACK_ADDR + PAGE_SIZE * STACK_PAGES;
(*ret_proc.frame).mode = CpuMode::User as usize;
(*ret_proc.frame).pid = ret_proc.pid as usize;

44
risc_v/src/syscall.rs
View File

@ -4,7 +4,7 @@
// 3 Jan 2020
use crate::{block::block_op,
cpu::{dump_registers, TrapFrame},
cpu::{dump_registers, TrapFrame, Registers},
fs,
page::{virt_to_phys, Table},
process::{Process, PROCESS_LIST, PROCESS_LIST_MUTEX, delete_process, get_by_pid, set_sleeping, set_waiting}};
@ -20,7 +20,7 @@ pub unsafe fn do_syscall(mepc: usize, frame: *mut TrapFrame) -> usize {
// Libgloss expects the system call number in A7, so let's follow
// their lead.
// A7 is X17, so it's register number 17.
let syscall_number = (*frame).regs[17];
let syscall_number = (*frame).regs[Registers::A7 as usize];
match syscall_number {
0 | 93 => {
// Exit
@ -29,7 +29,7 @@ pub unsafe fn do_syscall(mepc: usize, frame: *mut TrapFrame) -> usize {
},
2 => {
// Easy putchar
print!("{}", (*frame).regs[10] as u8 as char);
print!("{}", (*frame).regs[Registers::A0 as usize] as u8 as char);
mepc + 4
},
8 => {
@ -38,13 +38,13 @@ pub unsafe fn do_syscall(mepc: usize, frame: *mut TrapFrame) -> usize {
},
10 => {
// Sleep
set_sleeping((*frame).pid as u16, (*frame).regs[10]);
set_sleeping((*frame).pid as u16, (*frame).regs[Registers::A0 as usize]);
0
},
11 => {
// Add process to the scheduler. This is obviously insecure and
// we wouldn't do this realistically.
let my_proc = (*frame).regs[10] as *const Process;
let my_proc = (*frame).regs[Registers::A0 as usize] as *const Process;
if PROCESS_LIST_MUTEX.try_lock() {
if let Some(mut pl) = PROCESS_LIST.take() {
// As soon as we push this process on the list, it'll be
@ -53,10 +53,10 @@ pub unsafe fn do_syscall(mepc: usize, frame: *mut TrapFrame) -> usize {
PROCESS_LIST.replace(pl);
}
PROCESS_LIST_MUTEX.unlock();
(*frame).regs[10] = 1;
(*frame).regs[Registers::A0 as usize] = 1;
}
else {
(*frame).regs[10] = 0;
(*frame).regs[Registers::A0 as usize] = 0;
}
mepc + 4
},
@ -72,7 +72,7 @@ pub unsafe fn do_syscall(mepc: usize, frame: *mut TrapFrame) -> usize {
// from a user process using virt_to_phys. If this turns
// out to be a page fault, we need to NOT proceed with
// the read!
let mut physical_buffer = (*frame).regs[12];
let mut physical_buffer = (*frame).regs[Registers::A2 as usize];
// If the MMU is turned on, we have to translate the
// address. Eventually, I will put this code into a
// convenient function, but for now, it will show how
@ -86,7 +86,7 @@ pub unsafe fn do_syscall(mepc: usize, frame: *mut TrapFrame) -> usize {
let paddr =
virt_to_phys(table, (*frame).regs[12]);
if paddr.is_none() {
(*frame).regs[10] = -1isize as usize;
(*frame).regs[Registers::A0 as usize] = -1isize as usize;
return mepc + 4;
}
physical_buffer = paddr.unwrap();
@ -98,13 +98,13 @@ pub unsafe fn do_syscall(mepc: usize, frame: *mut TrapFrame) -> usize {
// could be a missing page somewhere in between.
let _ = fs::process_read(
(*frame).pid as u16,
(*frame).regs[10]
(*frame).regs[Registers::A0 as usize]
as usize,
(*frame).regs[11] as u32,
(*frame).regs[Registers::A1 as usize] as u32,
physical_buffer
as *mut u8,
(*frame).regs[13] as u32,
(*frame).regs[14] as u32,
(*frame).regs[Registers::A3 as usize] as u32,
(*frame).regs[Registers::A4 as usize] as u32,
);
// If we return 0, the trap handler will schedule
// another process.
@ -112,24 +112,16 @@ pub unsafe fn do_syscall(mepc: usize, frame: *mut TrapFrame) -> usize {
},
172 => {
// A0 = pid
(*frame).regs[10] = (*frame).pid;
(*frame).regs[Registers::A0 as usize] = (*frame).pid;
mepc + 4
},
180 => {
// println!(
// "Pid: {}, Dev: {}, Buffer: 0x{:x}, Size: {},
// Offset: {}", (*frame).pid,
// (*frame).regs[10],
// (*frame).regs[11],
// (*frame).regs[12],
// (*frame).regs[13]
// );
set_waiting((*frame).pid as u16);
let _ = block_op(
(*frame).regs[10],
(*frame).regs[11] as *mut u8,
(*frame).regs[12] as u32,
(*frame).regs[13] as u64,
(*frame).regs[Registers::A0 as usize],
(*frame).regs[Registers::A1 as usize] as *mut u8,
(*frame).regs[Registers::A2 as usize] as u32,
(*frame).regs[Registers::A3 as usize] as u64,
false,
(*frame).pid as u16,
);