Jordan Earls
A project to implement a console using the Mbed using VGA for video output and a PS/2 keyboard for the input. The eventual goal is to also include tools for managing SD cards, and a semi-self-hosting programming environment.
Dependencies: PS2_MbedConsole fastlib SDFileSystem vga640x480g_mbedconsole lightvm mbed
MbedConsole is a cool little project to have a self-contained computer all on an Mbed. So far it has VGA and PS/2 support and can stand alone without a computer powering it. Next planned features are SD card support and a lightweight programmable VM complete with a file editor and self-hosted assembler.
You can view additional details about it at http://earlz.net/tags/mbedconsole
Revision 8:f356684767ef, committed 2012-09-22
- Comitter:
- earlz
- Date:
- Sat Sep 22 04:14:01 2012 +0000
- Parent:
- 7:2ac6752d47d2
- Child:
- 9:4211d638b2e9
- Commit message:
- IF statements now work, which makes loops trivial. Also added a few opcodes
Changed in this revision
--- a/forth_machine.cpp Sat Sep 22 03:00:55 2012 +0000
+++ b/forth_machine.cpp Sat Sep 22 04:14:01 2012 +0000
@@ -81,11 +81,12 @@
int forth_execute(uint8_t* block, int length)
{
uint16_t pos=0;
+ printf("block length: %x\r\n",length);
while(pos<length)
{
- serial.getc();
+ //serial.getc();
Opcode op=(Opcode)block[pos];
- printf("opcode: %x\r\n",(int)op);
+ printf("pos: %x -- opcode: %x\r\n",(int)pos, (int)op);
switch(op)
{
case BranchTrue:
@@ -100,6 +101,7 @@
case BranchFalse:
if(!pl_pop()){
pos++;
+ serial.printf("branch false %x\r\n",(int)pos);
pos=*((uint16_t*)&block[pos]);
serial.printf("branch false %x\r\n",(int)pos);
}else{
@@ -140,6 +142,30 @@
pos++;
pl_push(pl_pop()%pl_pop());
break;
+ case Cgt:
+ pos++;
+ pl_push(pl_pop()>pl_pop());
+ break;
+ case Clt:
+ pos++;
+ pl_push(pl_pop()<pl_pop());
+ break;
+ case Cgte:
+ pos++;
+ pl_push(pl_pop()>=pl_pop());
+ break;
+ case Clte:
+ pos++;
+ pl_push(pl_pop()<=pl_pop());
+ break;
+ case Ceq:
+ pos++;
+ pl_push(pl_pop()==pl_pop());
+ break;
+ case Cneq:
+ pos++;
+ pl_push(pl_pop()!=pl_pop());
+ break;
case CallInt:
pos++;
uint32_t tmp=*(uint32_t*)&block[pos];
@@ -147,7 +173,7 @@
pos+=4;
break;
case Ret:
- return;
+ return 0;
default:
--- a/plEarlz.cpp Sat Sep 22 03:00:55 2012 +0000
+++ b/plEarlz.cpp Sat Sep 22 04:14:01 2012 +0000
@@ -25,7 +25,7 @@
-volatile BranchTarget *last_target=NULL;
+BranchTarget *last_target=NULL;
ErrorType pl_error=None;
@@ -127,9 +127,9 @@
}
-void push_target(uint16_t* address)
+void push_target(int address)
{
- volatile BranchTarget* target=(BranchTarget*)malloc(sizeof(BranchTarget));
+ BranchTarget* target=(BranchTarget*)malloc(sizeof(BranchTarget));
target->previous=last_target;
target->target=address;
last_target=target;
@@ -145,6 +145,10 @@
last_target=last_target->previous;
free((void*)tmp);
}
+inline void write_blockword(int pos,uint16_t val)
+{
+ *(uint16_t*)&pl_codeblock[pos]=val;
+}
int compile_word(char *word, WordType type) //returns 0 for success, 1 for ending word found, -1 for error
{
@@ -187,19 +191,18 @@
}
}else if(strlcmp("if", word, 3)==0){
- printf("if statement %x\r\n", pl_blockpos);
push_opcode(BranchFalse);
- push_target(push_opcode_word(0));
+ push_target(pl_blockpos);
+ push_opcode_word(0);
}else if(strlcmp("else", word, 5)==0){
- printf("else statement %x\r\n", pl_blockpos);
push_opcode(Branch);
- uint16_t* tmp=push_opcode_word(0);
- volatile uint16_t* tmp2=last_target->target;
- *tmp2=pl_blockpos;
+ int tmp=pl_blockpos;
+ push_opcode_word(0);
+ write_blockword(last_target->target,pl_blockpos);
pop_target();
push_target(tmp); //have to do it after we pop it or we fall into an infinite loop!
}else if(strlcmp("end", word, 4)==0){
- *(last_target->target)=pl_blockpos;
+ write_blockword(last_target->target,(uint16_t)pl_blockpos);
pop_target();
}else{
vputs("I don't know the word '");
@@ -270,15 +273,6 @@
int pl_shell()
{
- uint8_t* tmpf[20];
- push_target((uint16_t*)&tmpf[2]);
- *last_target->target=50;
- pop_target();
- push_target((uint16_t*)&tmpf[4]);
- *last_target->target=200;
- pop_target();
-
- printf("foo: %i %i\r\n", (int)*(uint16_t*)&tmpf[2], (int)*(uint16_t*)&tmpf[4]);
vputs(">>plEarlz -- A forth-ish shell<<\n");
printheapstats();
vputs("\n");
--- a/plEarlz.h Sat Sep 22 03:00:55 2012 +0000
+++ b/plEarlz.h Sat Sep 22 04:14:01 2012 +0000
@@ -71,8 +71,8 @@
**/
typedef struct TargetNode
{
- volatile uint16_t* target;
- volatile TargetNode* previous; //previous instead of next because we're going to "destroy" this list in reverse
+ int target; //position inside of codeblock. Can't use pointers because life is cruel and the block could be reallocated at anytime.
+ TargetNode* previous; //previous instead of next because we're going to "destroy" this list in reverse
} BranchTarget;
extern ErrorType pl_error;