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- #include <stdint.h>
- #include <stdio.h>
- #include <unistd.h>
- #include "emul.h"
- #ifdef STAGE2
- #include "stage1-bin.h"
- #include "blkfs-bin.h"
- #else
- #include "stage0-bin.h"
- #endif
-
- /* Staging binaries
-
- The role of a stage executable is to compile definitions in a dictionary and
- then spit the difference between the starting binary and the new binary.
-
- That binary can then be grafted to an exiting Forth binary to augment its
- dictionary.
-
- We could, if we wanted, run only with the bootstrap binary and compile core
- defs at runtime, but that would mean that those defs live in RAM. In may system,
- RAM is much more constrained than ROM, so it's worth it to give ourselves the
- trouble of compiling defs to binary.
-
- */
-
- // When DEBUG is set, stage1 is a core-less forth that works interactively.
- // Useful for... debugging!
- // By the way: there's a double-echo in stagedbg. It's normal. Don't panic.
-
- //#define DEBUG
- #define RAMSTART 0
- #define STDIO_PORT 0x00
- // To know which part of RAM to dump, we listen to port 2, which at the end of
- // its compilation process, spits its HERE addr to port 2 (MSB first)
- #define HERE_PORT 0x02
- // Port for block reads. Write 2 bytes, MSB first, on that port and then
- // read 1024 bytes from the DATA port.
- #define BLK_PORT 0x03
- #define BLKDATA_PORT 0x04
-
- static int running;
- // We support double-pokes, that is, a first poke to tell where to start the
- // dump and a second one to tell where to stop. If there is only one poke, it's
- // then ending HERE and we start at sizeof(KERNEL).
- static uint16_t start_here = 0;
- static uint16_t end_here = 0;
- static uint16_t blkid = 0;
- static unsigned int blkpos = 0;
-
- static uint8_t iord_stdio()
- {
- int c = getc(stdin);
- if (c == EOF) {
- running = 0;
- }
- return (uint8_t)c;
- }
-
- static void iowr_stdio(uint8_t val)
- {
- // we don't output stdout in stage0
- #ifdef DEBUG
- // ... unless we're in DEBUG mode!
- putchar(val);
- #endif
- }
-
- static void iowr_here(uint8_t val)
- {
- start_here <<=8;
- start_here |= (end_here >> 8);
- end_here <<= 8;
- end_here |= val;
- }
-
- #ifdef STAGE2
- static void iowr_blk(uint8_t val)
- {
- blkid <<= 8;
- blkid |= val;
- blkpos = blkid * 1024;
- }
-
- static uint8_t iord_blkdata()
- {
- return BLKFS[blkpos++];
- }
- #endif
-
- int main(int argc, char *argv[])
- {
- Machine *m = emul_init();
- m->ramstart = RAMSTART;
- m->iord[STDIO_PORT] = iord_stdio;
- m->iowr[STDIO_PORT] = iowr_stdio;
- m->iowr[HERE_PORT] = iowr_here;
- #ifdef STAGE2
- m->iowr[BLK_PORT] = iowr_blk;
- m->iord[BLKDATA_PORT] = iord_blkdata;
- #endif
- // initialize memory
- for (int i=0; i<sizeof(KERNEL); i++) {
- m->mem[i] = KERNEL[i];
- }
-
- // Run!
- running = 1;
-
- while (running && emul_step());
-
- #ifndef DEBUG
- // We're done, now let's spit dict data
- for (int i=start_here; i<end_here; i++) {
- putchar(m->mem[i]);
- }
- #endif
- return 0;
- }
-
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