add shell

programs/boot.vc5asm

@@ -60,29 +60,121 @@ key_press_int:
     mov r0, [counter]
     add r0, vcd_base
     mov r1, [kbd_code]
+
     cmp r1, 44 ; spacebar
     mov r2, rfl
     and r2, fl_eq
     jnz r2, .print_space
-    add r1, 61 ; scancode letter -> ascii
 
+    cmp r1, 40 ; enter
+    mov r2, rfl
+    and r2, fl_eq
+    jnz r2, .print_newline
+
+    cmp r1, 55 ; dot
+    mov r2, rfl
+    and r2, fl_eq
+    jnz r2, .print_dot
+
+    add r1, 61 ; scancode letter -> ascii
     mov [rsp], r1
     add rsp, 2
     call term_putc
+    ;call print_u16
     sub rsp, 2
-
     jmp .leave
+
 .print_space:
     mov r1, ' '
-
     mov [rsp], r1
     add rsp, 2
     call term_putc
     sub rsp, 2
+    jmp .leave
+
+.print_newline:
+    mov r1, '\n'
+    mov [rsp], r1
+    add rsp, 2
+    call term_putc
+    sub rsp, 2
+    jmp .leave
+
+.print_dot:
+    mov r1, ':'
+    mov [rsp], r1
+    add rsp, 2
+    call term_putc
+    sub rsp, 2
+    jmp .leave
 
 .leave:
     reti
 
+shell_start:
+    mov [rsp], rbp
+    add rsp, 2
+    mov rbp, rsp
+.loop_body:
+
+    mov r1, .prompt
+    mov r2, 5
+    add rsp, 4
+    mov [rsp-4], r1
+    mov [rsp-2], r2
+    call term_puts
+    sub rsp, 4
+
+    hlt
+    jmp .loop_body
+.leave:
+    mov rsp, rbp
+    sub rsp, 2
+    mov rbp, [rsp]
+    ret
+.prompt:
+    db "C ABC", 0
+
+term_puts:
+    mov [rsp], rbp
+    add rsp, 2
+    mov rbp, rsp
+
+    mov r1, [rbp-8]
+    mov r2, [rbp-6]
+
+    mov r3, 0
+    jmp .l1_cond
+.l1_body:
+    mov r4, r1
+    add r4, r3
+    mov r4, byte [r4]
+
+    add rsp, 8
+    mov [rsp-8], r1
+    mov [rsp-6], r2
+    mov [rsp-4], r3
+    mov [rsp-2], r4
+
+    call term_putc
+
+    mov r3, [rsp-4]
+    mov r2, [rsp-6]
+    mov r1, [rsp-8]
+    sub rsp, 8
+
+    add r3, 1
+.l1_cond:
+    cmp r3, r2
+    mov r0, rfl
+    and r0, fl_lt
+    jnz r0, .l1_body
+
+.leave:
+    mov rsp, rbp
+    sub rsp, 2
+    mov rbp, [rsp]
+    ret
 
 const term_width 20
 const term_height 12
@@ -163,8 +255,8 @@ term_scroll:
     mov r0, term_width
     mul r0, r1
     add r0, r2
-    mov r4, byte [vcd_base + term_width + r0]
-    mov byte [vcd_base + r0], r4
+    mov r3, byte [vcd_base + term_width + r0]
+    mov byte [vcd_base + r0], r3
 
     add r2, 1
 .l2_cond:
@@ -195,16 +287,6 @@ term_scroll:
 
     ret
 
-
-
-
-
-
-
-
-
-
-
 print_u16:
     mov [rsp], rbp
     add rsp, 2

src/assembler.cpp

@@ -1015,16 +1015,14 @@ auto Parser::parse_align() -> std::unique_ptr<Align>
     assert(test(TT::KwAlign));
     auto loc = m_tok.loc;
     step();
-    if (!test(TT::Ident)) {
-        error(current_loc(), "expected identifier");
+    if (!test(TT::Int)) {
+        error(current_loc(), "expected integer");
         return nullptr;
     }
-    auto ident = m_tok.text;
-    step();
     auto expr = parse_expr();
     if (not expr)
         return nullptr;
-    return std::make_unique<Align>(loc, ident, std::move(expr));
+    return std::make_unique<Align>(loc, std::move(expr));
 }
 
 auto Parser::parse_line() -> std::unique_ptr<Line>

src/assembler.hpp

@@ -102,7 +102,6 @@ namespace asmer {
 
     struct Align {
         Loc loc;
-        std::string_view ident;
         std::unique_ptr<Expr> expr;
     };
 

src/io_device.cpp

@@ -58,6 +58,9 @@ constexpr uint64_t char_data(uint8_t ch)
         case 'X': return 0x0066663C3C666666;
         case 'Y': return 0x0066663C18181818;
         case 'Z': return 0x007E7E0C18307E7E;
+
+        case ':': return 0x0018180000181800;
+
         default:  return 0x55AA55AA55AA55AA;
             // clang-format on
     }