duskos

commit 508a18b8d4a3d5f044187ebf3150f2c193d98cf5
parent 54bad5ff45ecd33fe462358ffae2956f13446b37
Author: Virgil Dupras <hsoft@hardcoded.net>
Date:   Sat, 13 Aug 2022 14:38:37 -0400

cvm: add the ability to mount any file on the host has a drive

For example, if you want to mount "pc.img" as a FAT, you would do:

S" pc.img" mountImage mountFATvolume value myfat
0 S" init.fs" myfat FAT :child value myid
myid myfat FAT :open value myhdl
40 myhdl FATFile :readbuf rtype

And it will yield something like:

\ Initialization for PC
: ARCH S" i386"  ok

Diffstat:
M
posix/glue.fs
 | 
3
+++
M
posix/vm.c
 | 
54
+++++++++++++++++++++++++++++++++++++++++++++---------

2 files changed, 48 insertions(+), 9 deletions(-)
diff --git a/posix/glue.fs b/posix/glue.fs
@@ -7,3 +7,6 @@ create _POSIXFS
   ' abort ,
 
 _POSIXFS ' activefs rebind
+
+: mountImage ( imgname -- drv )
+  _mountdrv here 512 , ['] _drv@ , ['] _drv! , ;
diff --git a/posix/vm.c b/posix/vm.c
@@ -49,7 +49,7 @@ struct VM {
 };
 
 static struct VM vm = {0};
-static FILE *bootfp;
+static FILE *fp;
 
 // Utilities
 static void vmabort() { vm.PC = MEMSZ + 1; }
@@ -256,7 +256,7 @@ static void _TO_() { // op: 12
 }
 
 static void BOOTRD() { // op: 13
-    ppush(fgetc(bootfp));
+    ppush(fgetc(fp));
 }
 
 static void STDOUT() { // op: 14
@@ -830,7 +830,7 @@ static void FREADBUF () { // op: 5f
     ppush((dword)res);
 }
 
-static void FCLOSE () { // op: 60
+static void FCLOSE() { // op: 60
     dword hdl = ppop();
     int fd = getfiledesc(hdl);
     if (fd) {
@@ -840,7 +840,43 @@ static void FCLOSE () { // op: 60
     }
 }
 
-#define OPCNT 0x61
+// ( imgname -- )
+static void MOUNTDRV() { // op: 61
+    char buf[64] = {0};
+    dword str = ppop();
+    byte slen = gb(str++);
+    memcpy(buf, &vm.mem[str], slen);
+    if (fp) {
+        fclose(fp);
+        fp = NULL;
+    }
+    fp = fopen(buf, "r+");
+    if (!fp) {
+        printf("Can't open %s.\n", buf);
+        BYEFAIL();
+    }
+}
+
+#define SECSZ 512
+// ( sec dst drv -- )
+static void DRVRD() { // op: 62
+    DROP();
+    dword dst = ppop();
+    dword sec = ppop();
+    fseek(fp, SECSZ * sec, SEEK_SET);
+    fread(&vm.mem[dst], SECSZ, 1, fp);
+}
+
+// ( sec src drv -- )
+static void DRVWR() { // op: 63
+    DROP();
+    dword src = ppop();
+    dword sec = ppop();
+    fseek(fp, SECSZ * sec, SEEK_SET);
+    fread(&vm.mem[src], SECSZ, 1, fp);
+}
+
+#define OPCNT 0x64
 static void (*ops[OPCNT])() = {
     JUMP, CALL, RET, LIT, BYE, BYEFAIL, QUIT, ABORT_,
     EXECUTE, CELL, VAL, ALIAS, DOES, SLIT, BR, CBR,
@@ -854,7 +890,7 @@ static void (*ops[OPCNT])() = {
     RSHIFT, LITN, EXECUTEWR, EXITWR, MOVE, MOVEWR, RTYPE, WNF,
     STACKCHK, MAYBEWORD, WORD, PARSE, REQ, FIND, APOS, COMPILING,
     SWR, STARTCOMP, STOPCOMP, RUNWORD, EXIT, FCHILD, FOPEN, FREADBUF,
-    FCLOSE};
+    FCLOSE, MOUNTDRV, DRVRD, DRVWR};
 
 static char *opnames[OPCNT] = {
     NULL, NULL, NULL, NULL, "bye", "byefail", "quit", "(abort)",
@@ -869,7 +905,7 @@ static char *opnames[OPCNT] = {
     "rshift", "litn", "execute,", "exit,", "move", "move,", "rtype", "(wnf)",
     "stack?", "maybeword", "word", "parse", "[]=", "find", "'", "compiling",
     ",\"", "]", "[", "runword", "exit", "_fchild", "_fopen", "_freadbuf",
-    "_fclose"};
+    "_fclose", "_mountdrv", "_drv@", "_drv!"};
 
 static void oprun1() { // run next op
     if (!memchk(vm.PC)) return;
@@ -959,15 +995,15 @@ static void buildsysdict() {
 // Interpret loop
 int main() {
     strcpy(fsids[0], "fs"); // Set FS root path
-    bootfp = fopen("posix/boot.fs", "r");
-    if (!bootfp) {
+    fp = fopen("posix/boot.fs", "r");
+    if (!fp) {
         printf("Can't open boot file.\n");
         return 1;
     }
     buildsysdict();
     vm.PC = find("(abort)");
     while (vm.PC < MEMSZ) oprun1();
-    fclose(bootfp);
+    if (fp) fclose(fp);
     if (vm.PC > MEMSZ) {
         fprintf(stderr, "Dumping memory to memdump.\n");
         FILE *fp = fopen("memdump", "w");