Add builtin symbols

boot/symbol.s

@@ -0,0 +1,104 @@
+# This Source Code Form is subject to the terms of the Mozilla Public License,
+# v. 2.0. If a copy of the MPL was not distributed with this file, You can
+# obtain one at https://mozilla.org/MPL/2.0/.
+
+.global symbol_table_build
+
+.include "boot/definitions.inc"
+
+.equ SYMBOL_PRIME, 1543
+
+.section .rodata
+
+.type symbol_builtin_name_int, @object
+symbol_builtin_name_int: .ascii "Int"
+.type symbol_builtin_name_word, @object
+symbol_builtin_name_word: .ascii "Word"
+.type symbol_builtin_name_byte, @object
+symbol_builtin_name_byte: .ascii "Byte"
+.type symbol_builtin_name_char, @object
+symbol_builtin_name_char: .ascii "Char"
+
+# Every type info starts with a word describing what type it is.
+
+# Primitive types have only type size.
+.type symbol_builtin_type_int, @object
+symbol_builtin_type_int: .word TYPE_PRIMITIVE
+	.word 4
+.type symbol_builtin_type_word, @object
+symbol_builtin_type_word: .word TYPE_PRIMITIVE
+	.word 4
+.type symbol_builtin_type_byte, @object
+symbol_builtin_type_byte: .word TYPE_PRIMITIVE
+	.word 1
+.type symbol_builtin_type_char, @object
+symbol_builtin_type_char: .word TYPE_PRIMITIVE
+	.word 1
+
+.section .bss
+
+# The first word of the symbol table is its length.
+# Then a list of type infos follows:
+#
+# record
+#   name: String
+#   info: ^TypeInfo
+# end
+.type symbol_table, @object
+symbol_table: .zero SYMBOL_PRIME
+
+.section .text
+
+# Build the initial symbols.
+#
+# Sets a0 to the pointer to the global symbol table.
+.type symbol_build, @function
+symbol_table_build:
+	la a0, symbol_table
+	addi t0, a0, 4
+
+	li t1, 3 # Length of the word "Int".
+	sw t1, 0(t0)
+	la t1, symbol_builtin_name_int
+	sw t1, 4(t0)
+	la t1, symbol_builtin_type_int
+	sw t1, 8(t0)
+	lw t1, 0(a0)
+	addi t1, t1, 1
+	sw t1, 0(a0)
+	addi t0, t0, 12
+
+	li t1, 4 # Length of the word "Word".
+	sw t1, 0(t0)
+	la t1, symbol_builtin_name_word
+	sw t1, 4(t0)
+	la t1, symbol_builtin_type_word
+	sw t1, 8(t0)
+	lw t1, 0(a0)
+	addi t1, t1, 1
+	sw t1, 0(a0)
+	addi t0, t0, 12
+
+	li t1, 4 # Length of the word "Byte".
+	sw t1, 0(t0)
+	la t1, symbol_builtin_name_byte
+	sw t1, 4(t0)
+	la t1, symbol_builtin_type_byte
+	sw t1, 8(t0)
+	lw t1, 0(a0)
+	addi t1, t1, 1
+	sw t1, 0(a0)
+	addi t0, t0, 12
+
+	li t1, 4 # Length of the word "Char".
+	sw t1, 0(t0)
+	la t1, symbol_builtin_name_char
+	sw t1, 4(t0)
+	la t1, symbol_builtin_type_char
+	sw t1, 8(t0)
+	lw t1, 0(a0)
+	addi t1, t1, 1
+	sw t1, 0(a0)
+	addi t0, t0, 12
+
+	ret