Replace CONFIG_THREAD_OPTIONROMS with a runtime config setting.

Replace the CONFIG_THREAD_OPTIONROMS option with the CBFS (or fw_cfg)
file "etc/threads".  This allows for the "threads during optionrom"
capability to be enabled/disabled without requiring SeaBIOS to be
recompiled.  A value of "2" in this file will enable threads to run
during option rom execution.

This change also allows for all threads to be disabled via the same
runtime config file.  Setting the file to a value of "0" will cause
SeaBIOS to perform all hardware initialization serially.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 24 insertions, 5 deletions

diff --git a/src/stacks.c b/src/stacks.c
index de71c1dd..6bcb3194 100644
--- a/src/stacks.c
+++ b/src/stacks.c
@@ -10,6 +10,7 @@
 #include "list.h" // hlist_node
 #include "malloc.h" // free
 #include "output.h" // dprintf
+#include "romfile.h" // romfile_loadint
 #include "stacks.h" // struct mutex_s
 #include "util.h" // useRTC
 
@@ -271,6 +272,24 @@ getCurThread(void)
     return (void*)ALIGN_DOWN(esp, THREADSTACKSIZE);
 }
 
+static int ThreadControl;
+
+// Initialize the support for internal threads.
+void
+thread_init(void)
+{
+    if (! CONFIG_THREADS)
+        return;
+    ThreadControl = romfile_loadint("etc/threads", 1);
+}
+
+// Should hardware initialization threads run during optionrom execution.
+int
+threads_during_optionroms(void)
+{
+    return CONFIG_THREADS && ThreadControl == 2;
+}
+
 // Switch to next thread stack.
 static void
 switch_next(struct thread_info *cur)
@@ -309,7 +328,7 @@ void
 run_thread(void (*func)(void*), void *data)
 {
     ASSERT32FLAT();
-    if (! CONFIG_THREADS)
+    if (! CONFIG_THREADS || ! ThreadControl)
         goto fail;
     struct thread_info *thread;
     thread = memalign_tmphigh(THREADSTACKSIZE, THREADSTACKSIZE);
@@ -452,7 +471,7 @@ static u32 PreemptCount;
 void
 start_preempt(void)
 {
-    if (! CONFIG_THREAD_OPTIONROMS)
+    if (! threads_during_optionroms())
         return;
     CanPreempt = 1;
     PreemptCount = 0;
@@ -463,7 +482,7 @@ start_preempt(void)
 void
 finish_preempt(void)
 {
-    if (! CONFIG_THREAD_OPTIONROMS) {
+    if (! threads_during_optionroms()) {
         yield();
         return;
     }
@@ -477,7 +496,7 @@ finish_preempt(void)
 int
 wait_preempt(void)
 {
-    if (MODESEGMENT || !CONFIG_THREAD_OPTIONROMS || !CanPreempt
+    if (MODESEGMENT || !CONFIG_THREADS || !CanPreempt
         || getesp() < MAIN_STACK_MAX)
         return 0;
     while (CanPreempt)
@@ -498,7 +517,7 @@ void
 check_preempt(void)
 {
     extern void _cfunc32flat_yield_preempt(void);
-    if (CONFIG_THREAD_OPTIONROMS && GET_GLOBAL(CanPreempt) && have_threads())
+    if (CONFIG_THREADS && GET_GLOBAL(CanPreempt) && have_threads())
         call32(_cfunc32flat_yield_preempt, 0, 0);
 }