hw/x86: Load configuration from multiboot module if found

diff --git a/platform/hw/multiboot.c b/platform/hw/multiboot.c
index e64c06773a93453ac14ffa2551b9621163353ef3..d20a28221d1fb405af2488b286973b3c9702684b 100644 (file)
--- a/platform/hw/multiboot.c
+++ b/platform/hw/multiboot.c
@@ -74,12 +74,39 @@ void
 multiboot(struct multiboot_info *mbi)
 {
        unsigned long cmdlinelen;
-       char *cmdline;
+       char *cmdline = NULL,
+            *mbm_name;
+       struct multiboot_mod_list *mbm;
 
        bmk_core_init(BMK_THREAD_STACK_PAGE_ORDER);
 
-       /* save the command line before something overwrites it */
-       if (mbi->flags & MULTIBOOT_INFO_CMDLINE) {
+       /*
+        * First (and for now, only) multiboot module loaded is used as a
+        * preferred source for configuration (currently overloaded to
+        * `cmdline').
+        * TODO: Split concept of `cmdline' and `config'.
+        */
+       if (mbi->flags & MULTIBOOT_INFO_MODS &&
+                       mbi->mods_count >= 1 &&
+                       mbi->mods_addr != 0) {
+               mbm = (struct multiboot_mod_list *)(uintptr_t)mbi->mods_addr;
+               mbm_name = (char *)(uintptr_t)mbm[0].cmdline;
+               cmdline = (char *)(uintptr_t)mbm[0].mod_start;
+               cmdlinelen =
+                       mbm[0].mod_end - mbm[0].mod_start;
+               if (cmdlinelen >= (BMK_MULTIBOOT_CMDLINE_SIZE - 1))
+                       bmk_platform_halt("command line too long, "
+                           "increase BMK_MULTIBOOT_CMDLINE_SIZE");
+
+               bmk_printf("multiboot: Using configuration from %s\n",
+                       mbm_name ? mbm_name : "(unnamed module)");
+               bmk_memcpy(multiboot_cmdline, cmdline, cmdlinelen);
+               multiboot_cmdline[cmdlinelen] = 0;
+       }
+
+       /* If not using multiboot module for config, save the command line
+        * before something overwrites it */
+       if (cmdline == NULL && mbi->flags & MULTIBOOT_INFO_CMDLINE) {
                cmdline = (char *)(uintptr_t)mbi->cmdline;
                cmdlinelen = bmk_strlen(cmdline);
                if (cmdlinelen >= BMK_MULTIBOOT_CMDLINE_SIZE)
@@ -87,7 +114,9 @@ multiboot(struct multiboot_info *mbi)
                            "increase BMK_MULTIBOOT_CMDLINE_SIZE");
                bmk_strcpy(multiboot_cmdline, cmdline);
        }
-       else
+
+       /* No configuration/cmdline found */
+       if (cmdline == NULL)
                multiboot_cmdline[0] = 0;
 
        if ((mbi->flags & MULTIBOOT_INFO_MEMORY) == 0)