makejv3: sort out skewing support

diff --git a/Kernel/tools/makejv3.c b/Kernel/tools/makejv3.c
index 00f7112..e0207e6 100644 (file)
--- a/Kernel/tools/makejv3.c
+++ b/Kernel/tools/makejv3.c
@@ -19,16 +19,17 @@
    
    One of the weirder disk formats emulation folk use */
 
-/* We should do skewing, but that makes writing the image fun, so it's
-   optional */
-
+/* FIXME: need a skew table for PC style media */
 static const int skew[2][18] = {
        {
-        0x06, 0x0C, 0x01, 0x07, 0x0D, 0x02, 0x08, 0x0E,
-        0x03, 0x09, 0x0F, 0x04, 0x0A, 0x10, 0x05, 0x0b,
-        0x11, 0x00},
+               0x01, 0x08, 0x05, 0x02, 0x09, 0x6, 0x03, 0x00,
+               0x07, 0x04
+       },
        {
-        0x01, 0x05, 0x09, 0x02, 0x06, 0x0A, 0x03, 0x00, 0x07, 0x04}
+               0x06, 0x0C, 0x01, 0x07, 0x0D, 0x02, 0x08, 0x0E,
+               0x03, 0x09, 0x0F, 0x04, 0x0A, 0x10, 0x05, 0x0b,
+               0x11, 0x00
+       },
 };
 
 static int skewed;
@@ -50,7 +51,8 @@ static void jvc_writeheaders(uint8_t * ptr)
                for (j = 0; j < nside; j++) {
                        for (k = 0; k < nsec; k++) {
                                *ptr++ = i;
-                               *ptr++ = skewed == 0 ? k : skew[ddens][k];
+                               /* DD media start at sector 1 like sane computers */
+                               *ptr++ = ddens + (skewed == 0 ? k: skew[ddens][k]);
                                *ptr++ = (0x80 * ddens) | (0x10 * j);
                        }
                }
@@ -87,6 +89,9 @@ static void jvc_writesectors(void)
        for (i = 0; i < ntrack; i++) {
                for (j = 0; j < nside; j++) {
                        for (k = 0; k < nsec; k++) {
+                               /* 0 relative sector */
+                               int s = skewed == 0 ? k: skew[ddens][k];
+                               lseek(infd, 256 * (s + nsec * j + (nsec * nside) * i), 0);
                                /* 0 itself is fine - we just blank the rest */
                                if (data && read(infd, buf, 256) < 0) {
                                        perror("read sectors");
@@ -106,7 +111,10 @@ static void jvc_pc_writesectors(void)
        int i, j, k;
        for (i = 0; i < ntrack; i++) {
                for (j = 0; j < nside; j++) {
-                       for (k = 1; k <= nsec; k++) {
+                       for (k = 0; k < nsec; k++) {
+                               /* 0 relative sector */
+                               int s = skewed == 0 ? k: skew[ddens][k];
+                               lseek(infd, 512 * (s + nsec * j + (nsec * nside) * k), 0);
                                /* 0 itself is fine - we just blank the rest */
                                if (data && read(infd, buf, 512) < 0) {
                                        perror("read sectors");
@@ -163,8 +171,8 @@ void main(int argc, char *argv[])
 
        if ((*p != 's' && *p != 'd') || p[1] != 'd')
                usage();
-       if (*p == 's')
-               ddens = 0;
+       if (*p == 'd')
+               ddens = 1;
        p += 2;
        while (isdigit(*p)) {
                ntrack = ntrack * 10 + (*p - '0');
@@ -184,12 +192,6 @@ void main(int argc, char *argv[])
                        exit(1);
                }
                data = 1;
-               if (skewed) {
-                       fprintf(stderr,
-                               "%s: skewing and data not supported together.\n",
-                               argv[0]);
-                       exit(1);
-               }
        }
        outfd = open(argv[optind], O_WRONLY | O_TRUNC | O_CREAT, 0666);
        if (outfd == -1) {