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SM64 Memory Map

Displaying 25 out of 85 addresses.

View: moderated | waiting (9)


RAM Address Length Type Context Description Details
$80064F80 Unknown Misc. Global Segment 0x02 constant location - Contains image data for the hud symbols and other textures. The segment is allocated by a hardcoded routine on startup.
$8006C680 Unknown Misc. Global Table with segment-offset pointers to the HUD symbol textures. Since some of the HUD symbols were removed in the USA release, some of the slots are left empty:

8006C6CC 00000000 - J
8006C6E8 00000000 - Q
8006C6FC 00000000 - V
8006C704 00000000 - X
8006C70C 00000000 - Z

You can restore the old symbols by patching in the images from the Japanese ROM, and modifying the pointers in this table.
$8007E200 Unknown Misc. Global Segment 0x15
$8007EC20 Unknown Misc. Global Segment 0x04 - Contains the data for Mario's model
$800EB180 Unknown Misc. Global Segment 0x13 - Behavior script segment
$800EC5F8 52 bytes Behaviour Global Behavior script - Purple switch
$800ED3FC 32 bytes Behaviour Global Behavior script - Spinning exclamation point
$800EDBC8 12 bytes Behaviour Global Behavior script - Misc level architecture (eg the castle tower)
$800EDC24 44 bytes Behaviour Global Tree's behavior script
$800EE040 56 bytes Behaviour Global Mario's behavior script

23000000 002500A0
0C000000 802CB1C0
0C000000 8029CA58
0C000000 802CB264
$800EE2F4 56 bytes Behaviour Global Bob-omb's behavior script
$800F0860 Unknown Geometry Layout Global Mario's decompressed geo-layout script
$800F8C4C Unknown Geometry Layout Global Decompressed geo-layout script for signs
$8018D47C 554 bytes Geometry Layout Global Bob-omb's decompressed geo-layout
$80195C54 Unknown Geometry Layout Overworld Decompressed geo-layout script for the castle tower
$801C1000 Unknown Misc. Global Segment 0x09 constant location. All level mesh textures are loaded here by the 0x1A level script command.
$80207700 512 bytes Misc. Global Start of EEPROM and goes up to 0x80207900
$80277EE0 Unknown Routine Global Function that assigns ram segments

Arguments: A0 = segment number, A1 = ram address
Returns: V0 = 0x80-prefix-less ram address

Essentially just: *(uint32*)(0x8033B400 + segment_number << 2) = ram_address & 0x00FFFFFF;
$80277F50 Unknown Routine Global Segment-offset to true ram address converter
Arguments: A0 = segmented address
Returns: V0 = true ram address
$80278120 118 bytes Routine Global Function that seems to be a memory allocator. Basically finds a desired amount of free space in the heap and returns a pointer to the area.

Arguments: A0 = block size
Returns: V0 = ram address
$80278504 264 bytes Routine Global DmaCopy(u32 dst, u32 bottom, u32 top);
dst being the RAM offset! bottom is the beginning ROM offset to copy the bytes and top is the end.
Takes three arguments.

ADDIU SP, SP, $FFE8 ; -24 to stack. Aka, make space.
SW RA, $0014 (SP) ; Push return address to stack.
LUI A0, $8034 ; Upper half address.
ORI A0, A0, $269D ; Lower half address. A0 = $8034269D
LUI A1, $001C ; ROM offset start (bottom)
ORI A1, $0D60 ; Lower part, A1 = $001C0D60
LUI A2, $0020 ; ROM offset end (top)
JAL $80278504 ; Jump to subroutine DmaCopy
ORI A2, $00D1 ; Is executed before JAL. Lower half.
LW RA, $0014 (SP) ; Load back our lost return address.
JR RA ; Jump to return address.
ADDIU SP, SP, $0018 ; Restores stack. (+24)

DmaCopy basically copies data from ROM to RAM. dst is the destination (as RAM offset), bottom is the start (as ROM offset) which is copied to RAM and top is the end. So, in our above example bytes from $001C0D60 (ROM) to $002000D1 (ROM) into $8034269D (RAM).
$80278610 124 bytes Routine Global Function that loads data from rom into the heap and returns a ram pointer to the data.

Arguments: A0 = rom start address, A1 = rom end address, A2 = allocation size (seems mostly unused?)
Returns: V0 = pointer to data after being loaded into ram
$802787D8 216 bytes Routine Global Function that loads MIO0 files into ram segments.
Arguments: A0 = ram segment number, A1 = rom address start, A2 = rom address end
$802792C0 84 bytes Routine Global EEPROM Save file checksum calculation routine
Arguments: A0 = address of buffer, A1 = buffer size, A2 = ? 00004441
Returns: 2 byte checksum to V0
$8027F4E0 164 bytes Routine Global MIO0 decoder
Arguments: A0 = pointer to mio0 file (in RAM), A1 = destination address for the decompressed file