rtl/gfx/firmware: implement firmware stub

1 files changed, 78 insertions, 0 deletions

diff --git a/rtl/gfx/firmware/main.c b/rtl/gfx/firmware/main.c
new file mode 100644
index 0000000..f75a9cb
--- /dev/null
+++ b/rtl/gfx/firmware/main.c
@@ -0,0 +1,78 @@
+struct hostif_ctrl
+{
+	unsigned arint   : 1;
+	unsigned awint   : 1;
+	unsigned rsvd2   : 6;
+	unsigned arvalid : 1;
+	unsigned awvalid : 1;
+	unsigned rdone   : 1;
+	unsigned wvalid  : 1;
+	unsigned bdone   : 1;
+	unsigned rsvd13  : 19;
+};
+
+struct hostif_ar
+{
+	unsigned valid : 1;
+	unsigned rsvd1 : 1;
+	unsigned addr  : 30;
+};
+
+struct hostif_aw
+{
+	unsigned valid : 1;
+	unsigned rsvd1 : 1;
+	unsigned addr  : 30;
+};
+
+struct hostif_r
+{
+	unsigned data : 32;
+};
+
+struct hostif_w
+{
+	unsigned data : 32;
+};
+
+struct hostif_b0
+{
+	unsigned valid : 1;
+	unsigned rsvd1 : 31;
+};
+
+#define HOSTIF_BASE 0x00300000
+#define HOSTIF_CTRL (*(volatile struct hostif_ctrl *)(HOSTIF_BASE + 0x00))
+#define HOSTIF_AR   (*(volatile struct hostif_ar *)  (HOSTIF_BASE + 0x04))
+#define HOSTIF_AW   (*(volatile struct hostif_aw *)  (HOSTIF_BASE + 0x08))
+#define HOSTIF_R    (*(volatile struct hostif_r *)   (HOSTIF_BASE + 0x0c))
+#define HOSTIF_W    (*(volatile struct hostif_w *)   (HOSTIF_BASE + 0x10))
+#define HOSTIF_B    (*(volatile struct hostif_b *)   (HOSTIF_BASE + 0x14))
+
+int main(unsigned magic, unsigned hw_rev)
+{
+	while (1) {
+		struct hostif_ar ar;
+		while (!(ar = HOSTIF_AR).valid);
+
+		switch (ar.addr & 3) {
+			case 0b00:
+				HOSTIF_R.data = magic;
+				break;
+
+			case 0b01:
+				HOSTIF_R.data = hw_rev;
+				break;
+
+			case 0b10:
+				HOSTIF_R.data = hw_rev;
+				break;
+
+			case 0b11:
+				HOSTIF_R.data = 1;
+				break;
+		}
+
+		while (!HOSTIF_CTRL.rdone);
+	}
+}