From 478cddd82e0c0c36e008dcf999c819d1295aa2bb Mon Sep 17 00:00:00 2001
From: Daniil Gentili <daniil@daniil.it>
Date: Mon, 20 Jun 2022 18:06:49 +0200
Subject: [PATCH] Refactoring

---
 Makefile         |  1 +
 include/reg.h    |  5 ++++
 src/boot.S       |  2 +-
 src/kernel.c     | 33 +++++++++++++++++++--
 src/mini_uart0.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 113 insertions(+), 3 deletions(-)
 create mode 100644 src/mini_uart0.c

diff --git a/Makefile b/Makefile
index 8686cc3..8d89a01 100644
--- a/Makefile
+++ b/Makefile
@@ -11,6 +11,7 @@ all: kernel8.img
 install: all
 	udisksctl mount -b /dev/mmcblk0p1
 	cp kernel8.img /run/media/daniil/*/
+	cp /run/media/daniil/*/blobcode.bin /run/media/daniil/*/bootcode.bin
 	umount /run/media/daniil/*
 	sync
 
diff --git a/include/reg.h b/include/reg.h
index 5025c27..2ef58da 100644
--- a/include/reg.h
+++ b/include/reg.h
@@ -20,3 +20,8 @@
 #define UART_BASE (0x7E201000-BUS_OFFSET)
 
 #define ST_CLO (0x7e003004 - BUS_OFFSET)
+
+#define ARM_BASE  (0x7E00B000 - BUS_OFFSET)
+
+// Basic configuration
+#define ARM_ID  (ARM_BASE+0x44c)
\ No newline at end of file
diff --git a/src/boot.S b/src/boot.S
index 1969449..56f4da7 100644
--- a/src/boot.S
+++ b/src/boot.S
@@ -16,5 +16,5 @@ _start:
 	mov	sp, #LOW_MEMORY // Initialize the kernel stack pointer to +4mb, growing downwards
 	bl	kernel_main     // kernel_main()
 	
-halt: 
+halt:
 	b halt
\ No newline at end of file
diff --git a/src/kernel.c b/src/kernel.c
index a71d125..3e1c9a4 100644
--- a/src/kernel.c
+++ b/src/kernel.c
@@ -2,12 +2,41 @@
 #include "reg.h"
 #include "utils.h"
 
+#define ARM_IDVAL        0x364D5241
+
+void uart_hex(int i) {
+    uart0_send_string("0x");
+    for (int x = 0; x < 8; x++) {
+        int c = 48 + ((i & 0xF0000000) >> 28); 
+        if (c == 48+10) {
+            uart0_send('A');
+        } else if (c == 48+11) {
+            uart0_send('B');
+        } else if (c == 48+12) {
+            uart0_send('C');
+        } else if (c == 48+13) {
+            uart0_send('D');
+        } else if (c == 48+14) {
+            uart0_send('E');
+        } else if (c == 48+15) {
+            uart0_send('F');
+        } else {
+            uart0_send(c);
+        }
+        i <<= 4;
+    }
+    uart0_send_string("\r\n");
+}
 void kernel_main(void)
 {
+	/*while(get32(ARM_ID) != ARM_IDVAL);
+	delay(500);
+
     uart0_init();
+	delay(1000);*/
     uart0_send_string("Hello, world!\r\n");
 
-    while (1) {
+    /*while (1) {
         uart0_send(uart0_recv());
-    }
+    }*/
 }
diff --git a/src/mini_uart0.c b/src/mini_uart0.c
new file mode 100644
index 0000000..68266c3
--- /dev/null
+++ b/src/mini_uart0.c
@@ -0,0 +1,75 @@
+#include "mini_uart.h"
+#include "reg.h"
+
+#define UART_DR (UART_BASE+0x0)
+#define UART_FR (UART_BASE+0x18)
+
+#define UART_IBRD   (UART_BASE+0x24)
+#define UART_FBRD   (UART_BASE+0x28)
+#define UART_LCRH   (UART_BASE+0x2C)
+#define UART_CR     (UART_BASE+0x30)
+#define UART_IMSC     (UART_BASE+0x38)
+#define UART_ICR    (UART_BASE+0x44)
+
+// UART clock baud rate divisor register
+// Why is this undocumented??
+#define CM_UARTDIV (0x7e1010f4-BUS_OFFSET)
+
+// UART control register
+// Why is this undocumented??
+#define CM_UARTCTL 0x7e1010f0
+
+
+// cucumber moment
+#define CM_PASSWORD 0x5a000000
+#define CM_SRC_OSC			1
+
+#define CM_UARTCTL_FRAC_SET                                0x00000200
+#define CM_UARTCTL_ENAB_SET                                0x00000010
+
+void uart0_init(void)
+{
+    unsigned int selector;
+    
+    selector = get32(GPFSEL1);
+    selector &= ~(7<<12);                   // clean gpio14
+    selector |= 4<<12;                      // set alt0 for gpio14
+    selector &= ~(7<<15);                   // clean gpio15
+    selector |= 4<<15;                      // set alt0 for gpio 15
+    put32(GPFSEL1,selector);
+
+    put32(GPPUD,0);
+    delay(150);
+    put32(GPPUDCLK0,(1<<14)|(1<<15));
+    delay(150);
+    put32(GPPUDCLK0,0);
+
+	put32(UART_CR, 0);
+	put32(UART_IMSC, 0);
+
+    //put32(CM_UARTDIV, CM_PASSWORD | 0x6666);
+	//put32(CM_UARTDIV, CM_PASSWORD | CM_SRC_OSC | CM_UARTCTL_FRAC_SET | CM_UARTCTL_ENAB_SET);
+
+	put32(UART_IBRD, 26);
+	put32(UART_FBRD, 3);
+    put32(UART_LCRH, (3 << 5) | (1 << 4));
+	put32(UART_CR, 0x301);
+}
+
+void uart0_send(char c)
+{
+    while(get32(UART_FR) & (1<<5));
+    put32(UART_DR, c);
+}
+char uart0_recv()
+{
+    while(get32(UART_FR) & (1<<4));
+    return put32(UART_DR) & 0xFF;
+}
+
+void uart0_send_string(const char *str)
+{
+    for (int i = 0; str[i] != '\0'; i++) {
+        uart0_send(str[i]);
+    }
+}
\ No newline at end of file