merged assembly and cpu docs

README.md

@@ -22,7 +22,7 @@ Program exited with code 0
 ```
 
 
-See the docs on [asembly](docs/assembly.md) and [the cpu](docs/CPU.md) for more detail on how to write assembly code for this emulator.
+See the docs on [asembly](docs/assembly.md) for more detail on how to write assembly code for this emulator.
 See the [list of implemented syscalls](docs/syscalls.md) for more details on how to syscall.
 
 Currently, symbols (such as `main:`) are looked-up at runtime. This allows for better debugging, I believe.

docs/CPU.md

@@ -1,13 +0,0 @@
-# The CPU
-
-The CPU emulates some RISC-V instructions:
-
-  * all loads/stores: `lb, lh, lw, lbu, lhu, sw, sh, sb`
-    * supported arg format is either `rd, imm(reg)` or `reg, reg, imm`
-  * all branch statements: `beq, bne, blt, bge, bltu, bgeu`
-  * all jumps `j, jal, jalr, ret`
-  * basic arithmetic: `add, addi, sub` (not `lui, auipc`)
-  * shifts: `sll, slli, srl, srli, sra, srai`
-  * `scall, ecall, sbreak, ebreak` (both `s` and `e` version are the same instrcution)
-  * compares (non immediate): `slt, sltu`, not `slti, sltiu`
-  * logiacl (non immediate): `and, or, xor` not (`andi, ori, xori`)

docs/assembly.md

@@ -1,23 +1,40 @@
 # Assembly
 
-Assembly tokenization should be workiung completely. It knows what instructions the CPU implementation supports and parses based on them.
+Assembly tokenization should be working completely. It knows what instructions the CPU implementation supports and parses based on them.
+
+
+## Instructions
+  * all loads/stores: `lb, lh, lw, lbu, lhu, sw, sh, sb`
+    * supported arg format is either `rd, imm(reg)` or `rd, reg, imm`
+  * all branch statements: `beq, bne, blt, bge, bltu, bgeu`
+  * all jumps `j, jal, jalr, ret`
+  * basic arithmetic: `add, addi, sub` (not `lui, auipc`)
+  * shifts: `sll, slli, srl, srli, sra, srai`
+  * `scall, ecall, sbreak, ebreak` (both `s` and `e` version are the same instruction)
+  * compares (non immediate): `slt, sltu` (not `slti, sltiu`)
+  * logical (non immediate): `and, or, xor` (not `andi, ori, xori`)
+  
+All unimplemented instructions can be added quite easily
+
 
 ## Pseudo-ops
 The following pseudo-ops are implemented as of yet:
 * `.space <len>` reverse <len> bytes of zero
 * `.ascii 'text'` put text into memory
 * `.asciiz 'text'` put text into memory (null terminated)
-* `.sextion .<name>` same as `.<name>` see sections:
+* `.section .<name>` same as `.<name>`, see sections
+* `.set <name>, <value>` to create a const symbol with a given value
+* `.global <name>` mark symbol `<name>` as a global symbol. It is available from all loaded programs
 
 ## Sections: 
 Currently only these three sections are supported: 
 * `data` read-write data (non-executable)
 * `rodata` read-only data (non-executable)
-* `.text` executable data (read-only)
+* `text` executable data (read-only)
+
 
 ## Allocating stack
 another pseudo-op is recognized: `.stack <len>`. This marks the executable as requesting at least `<len>` bytes of stack. 
-If the loader repsects this wish, the sp is initialized pointing to the end of the stack.
+If the loader respects this wish, the sp is initialized pointing to the end of the stack.
-
- 
 
+ 

docs/stack.md

@@ -1,10 +0,0 @@
-# The stack
-
-The stack is a continuous region of memory, located somewhere. The stack grows "downwards", meaning new values are pushed like this:
-```asm
-    add sp, sp, -4
-    sw  a0, sp, 0 
-
-```
-
-