Rework syscall ABI.

Syscalls now accept two parameters, allowing for things like "int count = read(buf, len)"
Rather than providing safe signatures for syscalls, the user is now given helper functions to safely parse incoming values, c-strings and slices.
This commit is contained in:
Toby Jaffey 2025-12-09 21:51:35 +00:00
parent f046a590c0
commit 76fba39a21
28 changed files with 543 additions and 537 deletions

View file

@ -4,18 +4,18 @@ const uvm32 = @cImport({
});
const std = @import("std");
pub inline fn syscall(id: u32, param: u32) u32 {
pub inline fn syscall(id: u32, param1: u32, param2: u32) u32 {
var val: u32 = undefined;
asm volatile ("ecall"
: [val] "={a1}" (val),
: [param] "{a0}" (param),
: [val] "={a2}" (val),
: [param1] "{a0}" (param1), [param2] "{a1}" (param2),
[id] "{a7}" (id),
: .{ .memory = true });
return val;
}
pub inline fn getc() ?u8 {
const key = syscall(uvm32.UVM32_SYSCALL_GETC, 0);
const key = syscall(uvm32.UVM32_SYSCALL_GETC, 0, 0);
if (key == 0xFFFFFFFF) {
return null;
} else {
@ -24,7 +24,7 @@ pub inline fn getc() ?u8 {
}
pub inline fn millis() u32 {
return syscall(uvm32.UVM32_SYSCALL_MILLIS, 0);
return syscall(uvm32.UVM32_SYSCALL_MILLIS, 0, 0);
}
// dupeZ would be better, but want to avoid using an allocator
@ -35,21 +35,21 @@ pub inline fn print(m: []const u8) void {
@memcpy(termination_buf[0..m.len], m);
termination_buf[m.len] = 0;
const s = termination_buf[0..m.len :0];
_ = syscall(uvm32.UVM32_SYSCALL_PRINT, @intFromPtr(s.ptr));
_ = syscall(uvm32.UVM32_SYSCALL_PRINT, @intFromPtr(s.ptr), 0);
}
pub inline fn println(m: []const u8) void {
@memcpy(termination_buf[0..m.len], m);
termination_buf[m.len] = 0;
const s = termination_buf[0..m.len :0];
_ = syscall(uvm32.UVM32_SYSCALL_PRINTLN, @intFromPtr(s.ptr));
_ = syscall(uvm32.UVM32_SYSCALL_PRINTLN, @intFromPtr(s.ptr), 0);
}
pub inline fn yield() void {
_ = syscall(uvm32.UVM32_SYSCALL_YIELD, 0);
_ = syscall(uvm32.UVM32_SYSCALL_YIELD, 0, 0);
}
pub inline fn putc(c:u8) void {
_ = syscall(uvm32.UVM32_SYSCALL_PUTC, c);
_ = syscall(uvm32.UVM32_SYSCALL_PUTC, c, 0);
}