lkmc v2-rc

Unsquashed version at v2-rc-unsquashed, but that cannot be merged as it
breaks bisects at several points. All bugs will not bisect to this
humongous change.

It all started with a conversion of the Bash scripts to Python, mainly
because I couldn't stand not being able to properly use --options for
run which has a million options.

Then since that required a full testing, I decided to do all the
refactorings that I had in mind at once, and so I did and it became
v2-rc.

This is the largest patch I have ever done! OMG a few weeks of extra time.
I'm never writing a Bash script for anything that starts getting big again.

Some of the features are:

* separate build-qemu and build-gem5 commands
* common: convert scripts to python. Add --option for everything
* rename build to build-buildroot now that we are splitting all the build
  commands, Linux kernel to follow
* move all git submodules to submodules/ and all buildroot packages to
  packages/
* refactor the out/ structure. Keep projects on toplevel, because guest
  projects separate archs and host ones don't, making a toplevel arch wrong
* do-release: rename to just release
  https://stackoverflow.com/questions/16174992/cant-get-argparse-to-read-quoted-string-with-dashes-in-it
* run: add --terminal and explain gem5 pdb
* just track the lvimrc
* store CLI kernel config fragment inside buildlroot to avoid conflicts
* gem5: document m5 initparam
* readme: make a bunch of things awesomer
* readme: fix broken refs
* parsec-benchmark: update to 75d55ac446a43c47efb1044844a108c6c330184c
  Could not fetch otherwise.
* gem5: M5_OVERRIDE_PY_SOURCE

packages/kernel_modules/user/uio_read.c

@@ -0,0 +1,111 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#uio */
+
+#if 1
+
+/* Adapted from: https://yurovsky.github.io/2014/10/10/linux-uio-gpio-interrupt */
+
+#define _XOPEN_SOURCE 700
+#include <fcntl.h> /* open */
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h> /* write */
+
+#include <assert.h>
+#include <sys/mman.h>
+
+int main(int argc, char **argv)
+{
+    char *dev = "/dev/uio0";
+    if (argc > 1) {
+        dev = argv[1];
+        exit(EXIT_FAILURE);
+    }
+    int fd = open(dev, O_RDWR);
+    if (fd < 0) {
+        perror("open");
+        exit(EXIT_FAILURE);
+    }
+
+    /* TODO not supported by this kernel module? */
+	/*int *addr = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);*/
+	/*if (addr == MAP_FAILED) {*/
+		/*perror("mmap");*/
+		/*assert(0);*/
+	/*}*/
+	/**addr = 0x12345678;*/
+
+    while (1) {
+        uint32_t info = 1;
+        size_t nb = write(fd, &info, sizeof(info));
+        if (nb < sizeof(info)) {
+            perror("write");
+            close(fd);
+            exit(EXIT_FAILURE);
+        }
+        nb = read(fd, &info, sizeof(info));
+        if (nb == sizeof(info)) {
+            printf(__FILE__ " read = %u\n", info);
+        }
+    }
+}
+
+#else
+
+/* Ripped from the kernel docs. */
+
+#define _XOPEN_SOURCE 700
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <unistd.h>
+
+int main()
+{
+    int uiofd;
+    int configfd;
+    int err;
+    int i;
+    unsigned icount;
+    unsigned char command_high;
+
+    uiofd = open("/dev/uio0", O_RDONLY);
+    if (uiofd < 0) {
+        perror("uio open:");
+        return errno;
+    }
+    configfd = open("/sys/class/uio/uio0/device/config", O_RDWR);
+    if (configfd < 0) {
+        perror("config open:");
+        return errno;
+    }
+    err = pread(configfd, &command_high, 1, 5);
+    if (err != 1) {
+        perror("command config read:");
+        return errno;
+    }
+    command_high &= ~0x4;
+    for(i = 0;; ++i) {
+        fprintf(stderr, "Interrupts: %d\n", icount);
+        err = pwrite(configfd, &command_high, 1, 5);
+        if (err != 1) {
+            perror("config write:");
+            break;
+        }
+        err = read(uiofd, &icount, 4);
+        if (err != 4) {
+            perror("uio read:");
+            break;
+        }
+
+    }
+    return errno;
+}
+
+#endif