From 999255e50832e6cf8e3db10922fa872586886ca1 Mon Sep 17 00:00:00 2001
From: Martijn de Vos <mdmartijndevos@gmail.com>
Date: Sun, 12 Feb 2023 09:14:08 +0100
Subject: [PATCH] Got some of the NAND initializations working

---
 hw/arm/ipod_touch_fmss.c         | 23 ++++++++++++++++++++++-
 include/hw/arm/ipod_touch_fmss.h |  4 ++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/hw/arm/ipod_touch_fmss.c b/hw/arm/ipod_touch_fmss.c
index 8fb1c1517b3c..6dfc2d1c6a68 100644
--- a/hw/arm/ipod_touch_fmss.c
+++ b/hw/arm/ipod_touch_fmss.c
@@ -1,5 +1,11 @@
 #include "hw/arm/ipod_touch_fmss.h"
 
+static void write_chip_info(IPodTouchFMSSState *s)
+{
+    uint32_t chipid[] = { 0xb614d5ad, 0xb614d5ad, 0xb614d5ad, 0xb614d5ad };
+    cpu_physical_memory_write(s->reg_target_addr, &chipid, 0x10);
+}
+
 static uint64_t ipod_touch_fmss_read(void *opaque, hwaddr addr, unsigned size)
 {
     //fprintf(stderr, "%s: read from location 0x%08x\n", __func__, addr);
@@ -10,7 +16,7 @@ static uint64_t ipod_touch_fmss_read(void *opaque, hwaddr addr, unsigned size)
         case FMSS__CS_BUF_RST_OK:
             return 0x1;
         case FMSS__CS_IRQ:
-            return 0x0;
+            return s->reg_cs_irq_bit;
         case FMSS__FMCTRL1:
             return (0x1 << 30);
         default:
@@ -24,6 +30,21 @@ static void ipod_touch_fmss_write(void *opaque, hwaddr addr, uint64_t val, unsig
 {
     IPodTouchFMSSState *s = (IPodTouchFMSSState *)opaque;
     fprintf(stderr, "%s: writing 0x%08x to 0x%08x\n", __func__, val, addr);
+
+    switch(addr) {
+        case 0xC00:
+            if(val == 0x0000ffb5) { s->reg_cs_irq_bit = 1; } // TODO ugly and hard-coded
+            break;
+        case FMSS__CS_IRQ:
+            if(val == 0xD) { s->reg_cs_irq_bit = 0; } // clear interrupt bit
+            break;
+        case FMSS_TARGET_ADDR:
+            s->reg_target_addr = val;
+            break;
+        case FMSS_CMD: // I assume this is a CMD register??
+            if(val == 0x8) { write_chip_info(s); }
+            break;
+    }
 }
 
 static const MemoryRegionOps fmss_ops = {
diff --git a/include/hw/arm/ipod_touch_fmss.h b/include/hw/arm/ipod_touch_fmss.h
index 55e7c551ff78..000938371102 100644
--- a/include/hw/arm/ipod_touch_fmss.h
+++ b/include/hw/arm/ipod_touch_fmss.h
@@ -14,12 +14,16 @@ OBJECT_DECLARE_SIMPLE_TYPE(IPodTouchFMSSState, IPOD_TOUCH_FMSS)
 #define FMSS__FMCTRL1       0x4
 #define FMSS__CS_IRQ        0xC0C
 #define FMSS__CS_BUF_RST_OK 0xC64
+#define FMSS_TARGET_ADDR    0xD08
+#define FMSS_CMD            0xD0C
 
 typedef struct IPodTouchFMSSState
 {
     SysBusDevice parent_obj;
     MemoryRegion iomem;
     qemu_irq irq;
+    uint32_t reg_cs_irq_bit;
+    uint32_t reg_target_addr;
 } IPodTouchFMSSState;
 
 #endif
\ No newline at end of file