Refactor kexec loading, add support for standalone dtb.img

Android.mk

@@ -23,7 +23,8 @@ LOCAL_SRC_FILES:= \
     fstab.c \
     workers.c \
     containers.c \
-    rom_quirks.c
+    rom_quirks.c \
+    kexec.c
 
 ifeq ($(ARCH_ARM_HAVE_NEON),true)
     LOCAL_SRC_FILES += col32cb16blend_neon.S

kexec.c

@@ -0,0 +1,114 @@
+/*
+ * This file is part of MultiROM.
+ *
+ * MultiROM is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * MultiROM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with MultiROM.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "kexec.h"
+#include "containers.h"
+#include "log.h"
+#include "util.h"
+
+// kexec --load-hardboot ./zImage --command-line="$(cat /proc/cmdline)" --mem-min=0xA0000000 --initrd=./rd.img
+// --mem-min should be somewhere in System RAM (see /proc/iomem). Location just above kernel seems to work fine.
+// It must not conflict with vmalloc ram. Vmalloc area seems to be allocated from top of System RAM.
+
+void kexec_init(struct kexec *k, const char *path)
+{
+    k->args = NULL;
+    kexec_add_arg(k, path);
+}
+
+void kexec_destroy(struct kexec *k)
+{
+    list_clear(&k->args, &free);
+}
+
+int kexec_load_exec(struct kexec *k)
+{
+    int i, len;
+
+    INFO("Loading kexec:\n");
+    for(i = 0; k->args && k->args[i]; ++i)
+    {
+        len = strlen(k->args[i]);
+
+        if(len < 480)
+            INFO("    %s\n", k->args[i]);
+        else
+        {
+            char buff[481];
+            char *itr;
+            const char *end = k->args[i]+len;
+            int chunk = 0;
+
+            for(itr = k->args[i]; itr < end; itr += chunk)
+            {
+                chunk = imin(480, end - itr);
+
+                memcpy(buff, itr, chunk);
+                buff[chunk] = 0;
+
+                INFO("    %s\n", buff);
+            }
+        }
+    }
+
+    if(run_cmd(k->args) == 0)
+        return 0;
+    else
+    {
+        ERROR("kexec call failed, re-running it to get info:\n");
+        char *r = run_get_stdout(k->args);
+        if(!r)
+            ERROR("run_get_stdout returned NULL!\n");
+
+        char *p = strtok(r, "\n\r");
+        while(p)
+        {
+            ERROR("  %s\n", p);
+            p = strtok(NULL, "\n\r");
+        }
+        free(r);
+
+        return -1;
+    }
+}
+
+void kexec_add_arg(struct kexec *k, const char *arg)
+{
+    list_add(strdup(arg), &k->args);
+}
+
+void kexec_add_arg_prefix(struct kexec *k, const char *prefix, const char *value)
+{
+    int len = strlen(prefix) + strlen(value) + 1;
+    char *arg = malloc(len);
+    snprintf(arg, len, "%s%s", prefix, value);
+
+    list_add(arg, &k->args);
+}
+
+void kexec_add_kernel(struct kexec *k, const char *path, int hardboot)
+{
+    if(hardboot)
+        kexec_add_arg(k, "--load-hardboot");
+    else
+        kexec_add_arg(k, "-l");
+    kexec_add_arg(k, path);
+}

kexec.h

@@ -0,0 +1,33 @@
+/*
+ * This file is part of MultiROM.
+ *
+ * MultiROM is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * MultiROM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with MultiROM.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef KEXEC_H
+#define KEXEC_H
+
+struct kexec
+{
+    char **args;
+};
+
+void kexec_init(struct kexec *k, const char *path);
+void kexec_destroy(struct kexec *k);
+int kexec_load_exec(struct kexec *k);
+void kexec_add_arg(struct kexec *k, const char *arg);
+void kexec_add_arg_prefix(struct kexec *k, const char *prefix, const char *value);
+void kexec_add_kernel(struct kexec *k, const char *path, int hardboot);
+
+#endif