Document functions

kernel/main.68k

@@ -4,13 +4,13 @@ main:
   jsr term_init
   jsr pmem_init
   move.l #0x1000, d0
-  jsr push_page
+  jsr push_frame
   move.l #0x2000, d0
-  jsr push_page
+  jsr push_frame
   move.l #0, d0
-  jsr pop_page
+  jsr pop_frame
-  jsr pop_page
+  jsr pop_frame
-  jsr pop_page
+  jsr pop_frame
   stop #0x2700
 
 .bss

kernel/pmem.68k

@@ -1,21 +1,25 @@
 .text
 .global pmem_init
+| Initialize the physical memory manager
+| Clobbers d0 and a0
 pmem_init:
 move.b #0x5, d0 | Get the pointer to the MMU card
 jsr find_first_card
 adda.l #0x10, a0
 move.l a0, mmu_tlb_clear_addr
-move.l #((map_page - 0xC00000)), d1 | Get the entry offset for the mapping page in d1
+move.l #((map_page - 0xC00000)), d0 | Get the entry offset for the mapping page in d0
-lsr.l #8, d1
+lsr.l #8, d0
-lsr.l #2, d1
+lsr.l #2, d0
 move.l #kernel_map_page, a0 | Get the address of the mapping entry for the mapping page in a0
-adda.l d1, a0
+adda.l d0, a0
 move.l a0, map_page_entry_addr
 rts
 
-.global push_page
+.global push_frame
-| Page to push in d0
+| Pushes a frame onto the stack
-push_page:
+| Frame to push in d0
+| Clobbers d0, d1, and a0
+push_frame:
 move.l map_page_entry_addr, a0
 move.l (a0), d1 | Read the mapping entry into d1
 andi.l #(~0xFFF), d1 | Clear the entry's flags to get the pointer to it's physical page
@@ -26,8 +30,11 @@ move.l #map_page, (a0)
 move.l d1, (map_page)
 rts
 
-.global pop_page
+.global pop_frame
-pop_page:
+| Pops a frame off the stack
+| Returns frame address in d0
+| Clobbers d1 and a0
+pop_frame:
 move.l map_page_entry_addr, a0
 move.l (a0), d0 | Read the mapping entry into d0
 btst #0, d0 | Check the entry's present flag

kernel/term.68k

@@ -1,4 +1,6 @@
 .global term_init
+| Initializes the terminal card driver
+| Clobbers d0, d1, and a0
 term_init:
 move.b #0x3, d0 | Get the pointer to the terminal card
 jsr find_first_card