Add stubdomain support. See stubdom/README for usage details.

- Move PAGE_SIZE and STACK_SIZE into __PAGE_SIZE and __STACK_SIZE in
  arch_limits.h so as to permit getting them from there without
  pulling all the internal Mini-OS defines.
- Setup a xen-elf cross-compilation environment in stubdom/cross-root
- Add a POSIX layer on top of Mini-OS by linking against the newlib C
  library and lwIP, and implementing the Unixish part in mini-os/lib/sys.c
- Cross-compile zlib and libpci too.
- Add an xs.h-compatible layer on top of Mini-OS' xenbus.
- Cross-compile libxc with an additional xc_minios.c and a few things
  disabled.
- Cross-compile ioemu with an additional block-vbd, but without sound,
  tpm and other details.  A few hacks are needed:
  - Align ide and scsi buffers at least on sector size to permit
  direct transmission to the block backend. While we are at it, just
  page-align it to possibly save a segment. Also, limit the scsi
  buffer size because of limitations of the block paravirtualization
  protocol.
  - Allocate big tables dynamically rather that letting them go to
  bss: when Mini-OS gets installed in memory, bss is not lazily
  allocated, and doing so during Mini-OS is unnecessarily trick while
  we can simply use malloc.
- Had to change the Mini-OS compilation somehow, so as to export
  Mini-OS compilation flags to the Makefiles of libxc and ioemu.

Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>

1 files changed, 167 insertions, 0 deletions

diff --git a/extras/mini-os/main.c b/extras/mini-os/main.c
new file mode 100644
index 0000000000..345f7e9487
--- /dev/null
+++ b/extras/mini-os/main.c
@@ -0,0 +1,167 @@
+/*
+ * POSIX-compatible main layer
+ *
+ * Samuel Thibault <Samuel.Thibault@eu.citrix.net>, October 2007
+ */
+
+#ifdef HAVE_LIBC
+#include <os.h>
+#include <sched.h>
+#include <console.h>
+#include <netfront.h>
+#include <time.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fs.h>
+#include <xenbus.h>
+#include <events.h>
+
+extern int main(int argc, char *argv[], char *envp[]);
+extern void __libc_init_array(void);
+extern void __libc_fini_array(void);
+
+struct thread *main_thread;
+
+#if 0
+#include <stdio.h>
+int main(int argc, char *argv[], char *envp[])
+{
+    printf("Hello, World!\n");
+    return 1;
+}
+#endif
+
+void _init(void)
+{
+}
+
+void _fini(void)
+{
+}
+
+static void call_main(void *p)
+{
+    char *args, /**path,*/ *msg, *c;
+    int argc;
+    char **argv;
+    char *envp[] = { NULL };
+    char *vm;
+    int i;
+    char path[128];
+
+    /* Let other parts initialize (including console output) before maybe
+     * crashing. */
+    //sleep(1);
+
+    start_networking();
+    init_fs_frontend();
+
+#ifdef CONFIG_QEMU
+    if (!fs_import) {
+        printk("No FS backend found, is it running?\n");
+        do_exit();
+    }
+
+    /* Fetch argc, argv from XenStore */
+    char domid_s[10];
+    int domid;
+    domid = xenbus_read_integer("target");
+    if (domid == -1) {
+        printk("Couldn't read target\n");
+        do_exit();
+    }
+    snprintf(domid_s, sizeof(domid_s), "%d", domid);
+
+    snprintf(path, sizeof(path), "/local/domain/%d/vm", domid);
+    msg = xenbus_read(XBT_NIL, path, &vm);
+    if (msg) {
+        printk("Couldn't read vm path\n");
+        do_exit();
+    }
+    printk("vm is at %s\n", vm);
+#else
+    msg = xenbus_read(XBT_NIL, "vm", &vm);
+    if (msg) {
+        printk("Couldn't read vm path\n");
+        do_exit();
+    }
+#endif
+
+    snprintf(path, sizeof(path), "%s/image/dmargs", vm);
+    free(vm);
+    msg = xenbus_read(XBT_NIL, path, &args);
+
+    if (msg) {
+        printk("Couldn't get stubdom args: %s\n", msg);
+        args = strdup("");
+    }
+
+    argc = 1;
+#ifdef CONFIG_QEMU
+    argc += 2;
+#endif
+    c = args;
+    while (*c) {
+	if (*c != ' ') {
+	    argc++;
+	    while (*c && *c != ' ')
+		c++;
+	} else {
+	    while (*c == ' ')
+		c++;
+	}
+    }
+    argv = alloca((argc + 1) * sizeof(char *));
+    argv[0] = "main";
+    argc = 1;
+#ifdef CONFIG_QEMU
+    argv[1] = "-d";
+    argv[2] = domid_s;
+    argc += 2;
+#endif
+    c = args;
+    while (*c) {
+	if (*c != ' ') {
+	    argv[argc++] = c;
+	    while (*c && *c != ' ')
+		c++;
+	} else {
+	    *c++ = 0;
+	    while (*c == ' ')
+		c++;
+	}
+    }
+    argv[argc] = NULL;
+
+    for (i = 0; i < argc; i++)
+	printf("\"%s\" ", argv[i]);
+    printf("\n");
+
+    __libc_init_array();
+    environ = envp;
+    tzset();
+
+    exit(main(argc, argv, envp));
+}
+
+void _exit(int ret)
+{
+    close_all_files();
+    __libc_fini_array();
+    printk("main returned %d\n", ret);
+    unbind_all_ports();
+    if (!ret) {
+	/* No problem, just shutdown.  */
+        struct sched_shutdown sched_shutdown = { .reason = SHUTDOWN_poweroff };
+        HYPERVISOR_sched_op(SCHEDOP_shutdown, &sched_shutdown);
+    }
+    do_exit();
+}
+
+int app_main(start_info_t *si)
+{
+    printk("Dummy main: start_info=%p\n", si);
+    main_thread = create_thread("main", call_main, si);
+    return 0;
+}
+#endif