Fix multicore ntsc artifact on PI4

src/armc-start.S

@@ -520,12 +520,27 @@ donerpi0_1_c:
 #ifdef USE_MULTICORE
 .section ".text._init_core"
 _init_core:     //only called with multicore Pi models
-#ifndef USE_MULTICORE_ON_PI2
-    bl     _get_hardware_id
-    cmp    r0, #_RPI2
-    ble    skip_init      //don't run on Pi 2, just fall into spin core instead
+#if defined(RPI4)
+	ldr	r1,=0xff842000
+    mov  r2,#0
+	str r2,[r1]		// disable GIC on rpi4
 #endif
-    // On a Raspberry Pi 2 we enter in HYP mode, and need to force a switch to supervisor mode
+
+    //1. Set the CPACR for access to CP10 and CP11, and clear the ASEDIS and D32DIS bits:
+    ldr     r0, =(0xf << 20)
+    mcr     p15, 0, r0, c1, c0, 2
+
+    // 2. Set the FPEXC EN bit to enable the NEON MPE:
+    mov     r0, #0x40000000
+    vmsr    fpexc, r0
+
+    // if kernel_old=0 enter in HYP mode and need to force a switch to SVC mode
+    //
+    // for now we assume kernel_old=1 and don't execute this core
+    //
+    // The logs show:
+    // SVC mode: cpsr ends with 1d3
+    // HYP mode: cpsr ends with 1a3
     mrs     r0, cpsr
     eor     r0, r0, #CPSR_MODE_HYP
     tst     r0, #CPSR_MODE_MASK
@@ -572,16 +587,6 @@ _init_continue:
     msr cpsr_c, #(CPSR_MODE_SVR | CPSR_IRQ_INHIBIT | CPSR_FIQ_INHIBIT )
     sub sp, r4, # C1_SVR_STACK
 
-    // Enable VFP ------------------------------------------------------------
-
-    //1. Set the CPACR for access to CP10 and CP11, and clear the ASEDIS and D32DIS bits:
-    ldr     r0, =(0xf << 20)
-    mcr     p15, 0, r0, c1, c0, 2
-
-    // 2. Set the FPEXC EN bit to enable the NEON MPE:
-    mov     r0, #0x40000000
-    vmsr    fpexc, r0
-
     bl     run_core
 skip_init:
 #endif

src/defs.h

@@ -24,7 +24,7 @@
 
 #define USE_MULTICORE
 
-//#define USE_MULTICORE_ON_PI2
+#define DONT_USE_MULTICORE_ON_PI2
 
 // Define how the Pi Framebuffer is initialized
 // - if defined, use the property interface (Channel 8)

src/rgb_to_hdmi.c

@@ -2003,7 +2003,7 @@ return extra;
 static void start_core(int core, func_ptr func) {
    printf("starting core %d\r\n", core);
 #ifdef RPI4
-//   *(unsigned int *)(0xff80008c + 0x10 * core) = (unsigned int) func;
+   *(unsigned int *)(0xff80008c + 0x10 * core) = (unsigned int) func;
 #else
    *(unsigned int *)(0x4000008c + 0x10 * core) = (unsigned int) func;
 #endif
@@ -3302,7 +3302,13 @@ void rgb_to_hdmi_main() {
    set_scaling(get_scaling(), 2);
    resolution_warning = 0;
    clear = BIT_CLEAR;
-
+   if (_get_hardware_id() >= _RPI2) {
+       if (get_core_1_available() !=0) {
+           log_info("Second core available");
+       } else {
+           log_info("Second core NOT available");
+       }
+   }
    while (1) {
       log_info("-----------------------LOOP------------------------");
       if (profile != last_profile || last_saved_config_number != saved_config_number) {
@@ -3762,8 +3768,16 @@ void kernel_main(unsigned int r0, unsigned int r1, unsigned int atags)
         printf("main running on core %u\r\n", _get_core());
         for (i = 0; i < 10000000; i++);
 #ifdef USE_MULTICORE
-        log_info("Starting core 1 at: %08X", _init_core);
-        start_core(1, _init_core);
+ #ifdef DONT_USE_MULTICORE_ON_PI2
+        if (_get_hardware_id() >= _RPI3 ) {
+ #else
+        if (_get_hardware_id() >= _RPI2 ) {
+ #endif
+            log_info("Starting core 1 at: %08X", _init_core);
+            start_core(1, _init_core);
+        } else {
+            start_core(1, _spin_core);
+        }
 #else
         start_core(1, _spin_core);
 #endif