Mab Virtual Machine

Stack Virtual Machine named after Mab - Queen of The Faires

                               .  .  .
                               |\/'\/|
                              .~/_~_\~\.
         /'\                ,//."   "\||\`               /'\
        |   \              '/||<9> <`\\\\|`             /   |
       |  '  `\            /|||   ;  `|\||`           /`  '  |
       |   \   `\__       ,/// \  ~  /`\\||`      __/`   /   |
       \  \   \    `\__   '|||' |` `| '||||'  __/`    /   /  /
       \     '         `\ '|||--'   '--||||'/`   /     '     /
        \    '   "        /'|'         '| \'       "   '    /
         ` \ .......... . ______      . _______ ........ / `         
     . _____      . _____.|    |      |.|      |__________________
    / /     \    / /     \.\   \_______| |    |.|     _______ _    \
   / /   /\  \  / /   /\  \.\    ________     |.|     |______\ \    |
  / /   /. \  \/ /   /. \  \.\   \     | |    |.|     __________   <
 / /   /  . \  \/   /  . \  \.\   \____|.|    |.|     |______/_/    |
|.|____|  |.|_______| |.|______|______________|.|__________________/

Memory Model

A linear array divided in 8x4KiB blocks. Every single block have only one owner indicated with mutex. If a proccess wants to write not own block, block mutex must be locked.

Opcode Model

First 2 bits describes sequence. Other 6 bits describes control and conditional flags. | JUMP | CONTROL FLAGS | CONDITIONAL FLAGS | | ----- | ------------- | ----------------- | | 2-bit | 3-bit | 3-bit |

Assembler Instruction

Each instruction is divided in 3 sections:

• Jump-Sequence Section, starts with :
• Control Flags Section, starts with '
• Conditional Flags Section, starts with "

Syntax

:<S|D|C|V>'[I][E][M]"[L][E][G]

Sequence-Jump Section

| code | letter | src (=dst−k) | dst (=src+k) | | ---- | ------ | -------------- | -------------- | | 0x0 | S | data src ptr | data src ptr | | 0x1 | D | data dst ptr | data dst ptr | | 0x2 | C | code ptr | code ptr | | 0x3 | V | data src | data dst |

Control-Flags Section

| code | letter | action | description | | ---- | ------ | --------------------------- | -------------------------- | | 0x4 | I | k=−k | inverts k  | | 0x8 | E | k=k×data[src]; src=src−1 | extends k | | 0x10 | M | sleep for locked mutex | locks proccess until write | Indicates mode to execute instruction with 1-3 ordered characters.

Conditional-Flags Section

| code | letter | meaning | action | description | | ---- | ------ | ------- | ----------- | ---------------------------------- | | 0x20 | L | lower | src<dst | source is lower than destination | | 0x40 | E | equal | src=dst | source is equal to destination | | 0x80 | G | greater | src>dst | source is greater than destination | Indicates condition to execute instruction with 1-3 ordered characters.