[SeaBIOS] [PATCH 1/4] Add call32_params() helper function.

[Kevin O'Connor]

Add helper function for calling 32bit functions with more than just
one parameter.

Signed-off-by: Kevin O'Connor 
---
 src/stacks.c | 27 +++++++++++++++++++++++++++
 src/stacks.h |  1 +
 2 files changed, 28 insertions(+)

diff --git a/src/stacks.c b/src/stacks.c
index 9c528f5..de71c1d 100644
--- a/src/stacks.c
+++ b/src/stacks.c
@@ -501,3 +501,30 @@ check_preempt(void)
     if (CONFIG_THREAD_OPTIONROMS && GET_GLOBAL(CanPreempt) && have_threads())
         call32(_cfunc32flat_yield_preempt, 0, 0);
 }
+
+
+/****************************************************************
+ * call32 helper
+ ****************************************************************/
+
+struct call32_params_s {
+    void *func;
+    u32 eax, edx, ecx;
+};
+
+u32 VISIBLE32FLAT
+call32_params_helper(struct call32_params_s *params)
+{
+    return ((u32 (*)(u32, u32, u32))params->func)(
+        params->eax, params->edx, params->ecx);
+}
+
+u32
+call32_params(void *func, u32 eax, u32 edx, u32 ecx, u32 errret)
+{
+    ASSERT16();
+    struct call32_params_s params = {func, eax, edx, ecx};
+    extern void _cfunc32flat_call32_params_helper(void);
+    return call32(_cfunc32flat_call32_params_helper
+                  , (u32)MAKE_FLATPTR(GET_SEG(SS), &params), errret);
+}
diff --git a/src/stacks.h b/src/stacks.h
index 5ee4adc..9fe8761 100644
--- a/src/stacks.h
+++ b/src/stacks.h
@@ -30,5 +30,6 @@ void start_preempt(void);
 void finish_preempt(void);
 int wait_preempt(void);
 void check_preempt(void);
+u32 call32_params(void *func, u32 eax, u32 edx, u32 ecx, u32 errret);

#endif // stacks.h