mega-usb: download memory command (for custom OS)

diff --git a/mega-usb/mega-usb.c b/mega-usb/mega-usb.c
index affa5c2..2649797 100644 (file)
--- a/mega-usb/mega-usb.c
+++ b/mega-usb/mega-usb.c
@@ -31,6 +31,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <arpa/inet.h> // hton
 #include <termios.h>
 #include <unistd.h>
 
@@ -73,7 +74,8 @@ static int write_to_cart(int fd, const void *data, size_t size)
 
        ret = write(fd, data, size);
        if (ret != size) {
-               perror("write");
+               fprintf(stderr, "write %d/%zd: ", ret, size);
+               perror("");
                exit(1);
                //return -1;
        }
@@ -83,13 +85,19 @@ static int write_to_cart(int fd, const void *data, size_t size)
 
 static int read_from_cart(int fd, void *data, size_t size)
 {
+       size_t got = 0;
        int ret;
 
-       ret = read(fd, data, size);
-       if (ret != (int)size) {
-               perror("read");
-               exit(1);
-               //return -1;
+       while (got < size) {
+               ret = read(fd, (char *)data + got, size - got);
+               if (ret <= 0) {
+                       fprintf(stderr, "read %d %zd/%zd: ",
+                               ret, got, size);
+                       perror("");
+                       exit(1);
+                       //return -1;
+               }
+               got += ret;
        }
 
        return 0;
@@ -153,9 +161,9 @@ static int send_file(int fd, const char *fname, const char *cmd)
        int i;
 
        f = fopen(fname, "rb");
-       if (f == NULL)
-       {
+       if (f == NULL) {
                fprintf(stderr, "fopen %s: ", fname);
+               perror("");
                return -1;
        }
 
@@ -207,6 +215,59 @@ out:
        return retval;
 }
 
+static int recv_file(int fd, const char *fname, unsigned int addr,
+       unsigned int size)
+{
+       int retval = -1;
+       char *buf = NULL;
+       FILE *f = NULL;
+       struct {
+               unsigned int addr;
+               unsigned int size;
+       } addr_size;
+       int ret;
+
+       f = fopen(fname, "wb");
+       if (f == NULL) {
+               fprintf(stderr, "fopen %s: ", fname);
+               perror("");
+               return -1;
+       }
+
+       buf = malloc(size);
+       if (buf == NULL) {
+               fprintf(stderr, "OOM?\n");
+               goto out;
+       }
+
+       send_cmd(fd, "*xd");
+
+       addr_size.addr = htonl(addr);
+       addr_size.size = htonl(size);
+       ret = write_with_check(fd, &addr_size, sizeof(addr_size), 'k');
+       if (ret)
+               return ret;
+
+       ret = read_from_cart(fd, buf, size);
+       if (ret)
+               goto out;
+
+       ret = fwrite(buf, 1, size, f);
+       if (ret != size) {
+               fprintf(stderr, "fwrite %d/%d: ", ret, size);
+               perror("");
+               goto out;
+       }
+
+       retval = 0;
+out:
+       if (f != NULL)
+               fclose(f);
+       free(buf);
+
+       return retval;
+}
+
 static void usage(const char *argv0)
 {
        printf("usage:\n"
@@ -220,6 +281,8 @@ static void usage(const char *argv0)
                "  *r<x> - run SDRAM contents as mapper x:\n"
                "    s - sms, m - md, o - OS app, c - cd BIOS, M - md10m\n"
                "upload commands must be followed by -f <file>\n"
+               "custom OS commands:\n"
+               "  *xd <addr> <size> <file> - download memory\n"
                , argv0);
        exit(1);
 }
@@ -286,7 +349,21 @@ int main(int argc, char *argv[])
                        pending_cmd = argv[arg];
                        continue;
                }
+               /* custom OS commands */
+               if (!strcmp(argv[arg], "*xd")) {
+                       unsigned int addr, size;
+                       if (arg + 3 >= argc)
+                               invarg(argc, argv, argc);
+                       addr = strtoul(argv[++arg], NULL, 0);
+                       size = strtoul(argv[++arg], NULL, 0);
+                       ret = recv_file(fd, argv[++arg], addr, size);
+                       if (ret)
+                               return ret;
+
+                       continue;
+               }
 
+               /* passthrough */
                ret = send_cmd_check_k(fd, argv[arg]);
        }