From 5633e6154a9a48e6d4c4491ca2f69cc63cbc5af0 Mon Sep 17 00:00:00 2001
From: pjht <pterpstra@pterpstra.com>
Date: Thu, 2 Nov 2023 18:29:11 -0500
Subject: [PATCH] Finish RAM card sort

---
 rom.68k | 34 ++++++++++++++++++++++++----------
 1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/rom.68k b/rom.68k
index 9d64d9b..f34448f 100644
--- a/rom.68k
+++ b/rom.68k
@@ -5,12 +5,14 @@ _start:
   bra.b find_first_card
 romfindret:
   move.l a0, a6 | Save the ROM card IO base in a6 for later
-  lea (0xF0, a6), a7 | Set up the stack at the end of the ROM's IO space RAM
-  move.l #0x8000, a1
-  bsr.w find_all_ram_cards
-  bsr.b find_largest_ram | Find the largest RAM card and put the IO base in a5
+  move.l #0x10000, a7 | Set up the stack at the end of the ROM card's RAM
+  bsr.w find_largest_ram | Find the largest RAM card and put the IO base in a5
   move.l a0, a5
   move.l d0, d7
+  move.l #0x8100, a1
+  bsr.w find_all_ram_cards
+  move.l #0x8100, a0
+  bsr.w sort_ram_cards
   move.w #0x4, d0 | Find a storage card and put the IO base in a4
   bsr.b find_first_card
   move.l a0, a4
@@ -81,6 +83,7 @@ fakestack:
 
 | 1KB buffer in a1
 | Returns list length in d0
+| Clobbers a1, d1
 find_all_ram_cards:
   move.b #0, d0 | d0 holds the number of RAM cards found.
   move.l #0xff0000, a0 | a0 holds the address of the current card.
@@ -94,24 +97,35 @@ farc_loop:
   addq.b #1, d0 | Increment the count of found RAM cards
   bra.b farc_loop | Loop back and check the next card
 farc_done:
+  move.l #0, (a1) | Write a null terminator on the end of the list
   rts
 
+| optimized bubble sort to sort RAM cards by size
 | Buffer in a0
 | Length in d0
-| optimized bubble sort to sort RAM cards by size
+| Clobbers d1, d2, d3, d4, a1, a2
 sort_ram_cards:
 move.b #0, d1 | d1 = newlen
 move.b #1, d2 | d2 = i
+move.l a0, a1 | a1 holds the pointer to the current pair
 src_inner_loop:
-| todo compare sizes
-| PSEUDO: cmp snd, fst
+cmp.b d0, d2 | if i >= length, exit the inner loop
+bge.b src_inner_loop_done
+move.l (a1), a2 | Read the first card's size
+move.l (0x4, a2), d3
+move.l (4, a1), a2 | Read the second card's size
+move.l (0x4, a2), d4
+cmp.l d3, d4 | if d4 <= d3, branch to src_pair_sorted
 ble.b src_pair_sorted
-| todo swap values
+move.l (a1), d3 | Read the first value
+move.l (0x4, a1), d4 | Read the second value
+move.l d3, (0x4, a1) | Write the first value where the second value was
+move.l d4, (a1)+ | Write the second value where the first value was and increment a1 for the next pair
 move.b d2, d1 | i = newlem
 src_pair_sorted:
 addq.b #1, d2 | i++
-cmp.b d0, d2 | if i < length,  branch to inner loop
-blt.b src_inner_loop 
+bra.b src_inner_loop
+src_inner_loop_done:
 move.b d1, d0 | len = newlen
 cmp #1, d0 | if n > 1, branch to outer loop
 bgt.b sort_ram_cards