cisc-0.2 - An emulator for the Sux instruction set.

Age	Commit message (Collapse)	Author
2021-05-09	Subtract another 16 from the size in clr_arr.HEAD master	mrb0nk500
	This fixes a bug where it would zero out the info of the next malloc'd block.
2021-05-09	Replace call to memcpy, with call to memcpy_dir.	mrb0nk500
	This fixes a bug where when shifting the line left, it would overwrite everything after the cursor with the character at the cursor's position. The reason this was happening is because memcpy copies from start to end, and because the destination is more than one byte ahead of the source, it overwrites the next length source bytes, which will repeat until it's copied n bytes.
2021-05-09	Add a end to start version of memcpy, and a selectable	mrb0nk500
	direction version of memcpy. This can help with some subroutines/functions like shftln, which need to copy data in a certain direction depending on the condition.
2021-05-08	Fixed a bug in print_char caused by not zero extending	mrb0nk500
	`b`.
2021-05-08	Fixed a bug in print_str to do with clobbered	mrb0nk500
	registers. This was due to print_char clobbering `d` when calling get_index.
2021-05-08	Replace get_ctrlidx with get_index in print_char.	mrb0nk500
	This helps reduce code duplication, and makes it easier to both read, and add new handlers.
2021-05-08	Add a new subroutine called get_index.	mrb0nk500
	This subroutine gets the index of a given character from a string. This will help in replacing some routines like get_ctrlidx, isdelm, and isdelm2.
2021-05-08	Get the pointer from the control code handler table	mrb0nk500
	using SIB, rather than with lsl. This doesn't increase, or decrease the code size, but does make it both more compact, and easier to read.
2021-05-08	Rewrite `clr_arr` to use the ortho extension.	mrb0nk500
	This makes the code much smaller than the previous version.
2021-05-08	Replace all instances of $/0x1B with the escape	mrb0nk500
	sequence for the escape character.
2021-05-08	Start replacing the numbered duplicate local symbols	mrb0nk500
	with deeper scope local symbols. This is done to make the code easier to read.
2021-04-04	- Fixed a bug to do with how SIB operands were parsed	mrb0nk500
	in the assembler. - Rewrote more of the SuB Suite to use the new calling convention. - Fixed a bug to do with SIB operands in the emulator's disassembler. - Made the MMV instruction not require a loop prefix for copying data.
2021-02-25	- Implemented the multiply expression into the assembler.	mrb0nk500
	- Implemented support for the SIB addressing mode into the assembler. SIB is short for "Scale Index, and Base", and works much like x86's version of SIB (scale*index+base), although my version supports any scale value between 1, and 256. - Redid the line shifting routine in SuBEditor. It now uses memcpy, and memset to do that, and also supports shifting the line left, or right by any number of characters.
2021-02-13	- Reverted back one commit before the previous commit.	mrb0nk500
	This is because the previous commit actually created a bug, rather than fixing one. - Added JMP, and JSR to the ortho extension, and implemented them both in the assembler, and emulator.
2021-01-27	- Fixed some bugs in the emulator.	mrb0nk500
	- Started work on implementing the Super VIA emulation. - Added support for disabling disassembly per instruction, when in debug mode. - Did some more work on rewriting the SuB Suite to work with the new calling convention. - Rewrote the symbol handling code in the emulator's assembler, to make it both simpler, and to add support for arbitrarily deep symbol scopes. - Added support for arbitrarily deep local symbol scopes. For example, to declare a symbol of depth 2, you add two '@' characters to the start of the symbol name. In other words, the number of '@' characters before the symbol name is what determines the scope of that symbol. And to use a symbol thats outside the current scope, you would use the same syntax as using a struct member, so you would do `global.local`.
2020-12-08	- Implemented support for the Orthogonal extension into	mrb0nk500
	both the assembler, and the emulator. I finally figured out how I could get support for the Ortho extension implemented into the old assembler. The only reason for doing this, is to buy me some while I start work on the new assembler, and to help me get an idea for how to do the same in the new assembler.
2020-11-20	- Implemented support for Sux's base extension.	mrb0nk500
	This is the biggest milestone I've reached for this project, since the base extension changes alot about what Sux can do by default, and now makes it a viable instruction set for modern day use, when compared with other instruction sets.
2020-11-20	- Cleaned up a bit of the code.	mrb0nk500
	- Made the debug print for the CPU flags more readable. - Started work on implementing line number support into SuBAsm.
2020-10-06	- Removed some debugging stuff from the SuB Suite.	mrb0nk500

2020-10-06	- Made the stack pointer 64 bit, rather than 16 bit.	mrb0nk500
	This is to allow for making the stack bigger for anything that needs to change the size of it. - Made the SuB Suite set the stack pointer to the end of the usable RAM, and allow for changing the stack size. In this case, the size of the stack is currently set to 192K, with the end of the heap being just below the stack.
2020-10-05	- Added a routine for testing the SuB Suite's	mrb0nk500
	implementation of free(), although it's commented out. - Removed the sbc() function from the emulator, since sbc can be done by just inverting the second operand of adc.
2020-10-04	- Added support for reading, and writing outside the	mrb0nk500
	emulator's memory. All reads outside of the emulator's memory give back $/0xFF bytes, while all writes outside of the emulator's memory are ignored. - Implemented malloc(), and free() in the SuB Suite. In order to do this, I had to add support for a heap, which I did by reserving the first 3 banks of the address space (the first 192K), and by adding a routine that finds the end of the RAM. In this case, I set the starting address for the routine at bank 3 (bank 4 with one indexing), but, the routine's starting address isn't hardcoded, and thus, any starting address can be passed as an argument. The routine uses the fact that we can now read/write outside the emulator's memory, and also uses the fact that writing outside the emulator's memory will be ignored, and that reading outside the emulator's memory will always read $/0xFF bytes, and uses that to signal that it's reached the end of the RAM. - Added a test program for getting the size of RAM starting at address $/0x20000.
2020-09-24	- Fixed some more bugs with struct, and union handling.	mrb0nk500

2020-09-21	- Fixed some issues with how structs, and unions were	mrb0nk500
	handled. - Added a function called fix_symtree(), which when called. will rearrange the symbol tree based on the order they're declared in by the token stream. The reason I wrote this, was to make sure the symbol tree could be printed correctly. - Optimized print_symtree() to now use tail recursion. - Started adding all of the SuB Suite's structs.
2020-08-30	- Did some more work on SuBAsm's lexer.	mrb0nk500
	- Optimized the memory read, and write functions. - Made the emulator faster, and cleaner in general.
2020-08-17	- Fixed some bugs in the emulator's assembler.	mrb0nk500
	- Simplified the effective address functions. - Made SuBEditor a bit faster. - JSR, and RTS now support using the RS prefix, which is used to specify the return address size, with an RS prefix of 0 being a return address size of 64 bits, rather than 8 bits.
2020-08-12	- Refactored the escape sequence parsing, and handling.	mrb0nk500
	It now uses a struct to store the escape sequence. Before it handles the escape sequence, it parses it, which includes things like getting any arguments that are supplied, and getting the mode type. - Moved the code that handles control codes to a separate function. The reason for doing this was because I wanted to make the escape sequence handling faster, but also make the code more readable at the same time. I got the idea to do this from st, a terminal emulator created by the suckless.org project.
2020-08-09	Added the bitwise OR, left shift, and right shift	mrb0nk500
	expressions to the emulator's assembler.
2020-08-08	- Refactored the opcode table, in order to make the	mrb0nk500
	instruction formatting simpler. - Refactored the instruction table of the emulator's assembler, it now has two parts, the addressing mode bits, and the base value. The base value is what's used to generate the actual opcode, with the addressing mode bits telling the assembler what addressing modes this instruction supports. The reason for doing this was to use less space. For comparison, the previous version used 870 bytes for the instruction table, while the new version uses only 222 bytes. The new version is nearly 4 times smaller than the pervious version. - The B register based ALU instructions now use their own addressing mode, and are specified by using 'b' as the operand for those instructions. For example, to add the Accumulator with the B register, you now use "ADC B" instead of "AAB".
2020-08-08	Did a ton of stuff.	mrb0nk500
	- Changed the file structure of the SuB Suite, so that all variable declarations, symbols, and constants are in a single file. - Moved the C library functionss into a separate file, and made them use stack frames. - Added support for using the emulator's assembler for realtime debugging, to enter it, get in to stepping mode by pressing Ctrl+s, press any other key, then press F1, The reason for having to press some other key before pressing F1 is because it only allows entering the assembler when the keyboard is not ready. - Added the ".res" directive to the emulator's assembler, the ".res" directive tells the assembler to reserve however many bytes specified by the operand. - Fixed some bugs in the emulator's assembler.
2020-07-06	- Implemented a new opcode table.	mrb0nk500
	- Added a new preifx called the OF prefix, which adds the contents of a specific register to the current operand. - Added a table generator, which parses opcode table csv files.
2020-06-22	Did some more stuff.	mrb0nk500
	- Fixed some bugs in the emulator's assembler. - Worked on SuBAsm's lexer some more. - Created a new directory for the SuB suite, and moved all of the SuB suite's files in there.