mention globabls.asm

Added handling for backspace character

MEMORY.md

@@ -0,0 +1,21 @@
+# Memory Map
+
+To not have to allocate a ton of things at run time the Standard Library uses a static memory map for some purposes
+
+## Overview
+
+| Start | Use |
+| ---- | ---- |
+| `0x0` | Reset Vector |
+| `0x16` | Zero Page |
+| `0x100` | User Code |
+| `?` | Library Code |
+| `0x1_0000` | LUTs |
+| `?` | heap |
+| `0xXXF0_0000` | Stack |
+| `0xXXFF_0000` | quick access |
+
+## Zero Page
+Some values are needed not often enough to get their own special register, but often enough that it makes sense to keep them at a quickly accessible location.
+This is what the zero page is for. its position in memory allows us to load them into a register with a single instruction.
+

README.md

@@ -3,7 +3,8 @@
 This is a standard library for symphony.
 It is both intended as a practical toolkit to develop more complex software as well as a teaching resource.
 
-If you just want to use the standard library [[src/stdlib.asm]] is your main header, include it after your code.
+If you just want to use the standard library [[stdlib.asm]] is your main header, include it after your code.
+You also need to include [[globals.asm]] as the first line in your assembly file.
 
 If you are using it as a learning resource have a look at the [teaching folder](teaching).
 

globals.asm

@@ -0,0 +1,10 @@
+jmp 0x100
+
+@0x10
+screen:
+    frambuffer_ptr: U32 0x0
+    size: U32 0x0
+    position_xy: U32 0x0
+    mode: U32 0x0
+
+@0x100

src/imath.asm

@@ -4,53 +4,22 @@
 ; r2 - The second value
 ; Result:
 ; r1 - The lower 32 bits of the result
-; Clobbers: r2, r3, r4, r5, r6
+; Clobbers: r2, r3, r4, r5
 pub mul_low:
-	cmp r1, r2
-	jbe mul_low_noswap
-	xor r1, r2, r1
-	xor r2, r1, r2
-	xor r1, r2, r1
-	; Passthrough
+	mov r3, 0 ; result
+	mov r4, 31 ; loop counter
 	
-; Multiplies r1 and r2, returning the lower part of the result
-; This method assumes r1 is smaller than r2, which results in faster execution
-; Arguments:
-; r1 - The first value
-; r2 - The second value
-; Result:
-; r1 - The lower 32 bits of the result
-; Clobbers: r2, r3, r4, r5, r6
-pub mul_low_noswap:
-	mov r4, 0 ; r4 has the result
-	mov r6, mul_loop_end
-	add r3, r2, r2
+	mul_low_loop:
+		asr r5, r2, 31
+		and r5, r5, r1
+		lsl r5, r5, r4
+		add r3, r3, r5
+		lsl r2, r2, 1
+		sub r4, r4, 1
+		cmp r4, 0
+		jge mul_low_loop
+	mov r1, r3
 	
-	mul_loop:
-		and r5, r1, 14 ; Taking the first four bits, discarding the odd
-		lsl r5, r5, 1 ; 0000 - 0, 0001 - 2, 0010 - 4, 0011 - 8, etc.
-		sub r5, r6, r5
-		jmp r5
-		
-		add r4, r4, r3
-		add r4, r4, r3
-		add r4, r4, r3
-		add r4, r4, r3
-		add r4, r4, r3
-		add r4, r4, r3
-		add r4, r4, r3
-		mul_loop_end:
-			mov flags, r1
-			jne mul_skip_one
-			add r4, r4, r2
-			mul_skip_one:
-			lsl r2, r2, 4
-			lsl r3, r3, 4
-			lsr r1, r1, 4
-			cmp r1, zr
-			jne mul_loop
-
-	mov r1, r4
 	jmp r13
 
 ; Calculates the absolute value of the value provided in the r1 register

src/stdlib.asm

@@ -1,6 +1,5 @@
 pub include bit
 pub include imath
-pub include array
 pub include console
 
 ; Needs to be last!