Cleanup and get the program to a basic Hello, World program.

Add separate source file for initializing the uart for stdout.

3 files changed, 79 insertions, 156 deletions

diff --git a/src/init.c b/src/init.c
index 1d9474a..c402f17 100644
--- a/src/init.c
+++ b/src/init.c
@@ -1,6 +1,7 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include "io.h"
 #include "isr_vector.h"
 
 void on_reset(void);
@@ -11,9 +12,11 @@ default_irq_handler(void)
   return;
 }
 
-#define WEAK_IRQ(irq)                                                  \
-  void __attribute__((                                                 \
-      weak, alias("default_irq_handler"), __section__(".isr_vector.routines"))) \
+#define WEAK_IRQ(irq)                       \
+  void __attribute__((                      \
+      weak,                                 \
+      alias("default_irq_handler"),         \
+      __section__(".isr_vector.routines"))) \
   irq(void)
 
 WEAK_IRQ(irq_on_reset);
@@ -60,8 +63,8 @@ extern uint32_t BSS_STOP;
 
 static inline void set_mtvec(void* vector_table)
 {
-  uint32_t mtvec = (uint32_t) vector_table;
-  mtvec |= 1; // Set interrupt table mode to "VECTORED"
+  uint32_t mtvec = (uint32_t)vector_table;
+  mtvec |= 1;  // Set interrupt table mode to "VECTORED"
   asm volatile("csrw mtvec, %0" : : "r"(mtvec));
 }
 
@@ -107,6 +110,10 @@ static __attribute((__section__(".sinit.1"))) void start(void)
   init_data_segments();
   /* Set the mtvec to the isr_vector. */
   set_mtvec(&isr_vector);
+
+  /* Initialize stdout. */
+  init_uart1_for_stdout();
+
   /* Jump to main */
   main();
 }
diff --git a/src/io.c b/src/io.c
new file mode 100644
index 0000000..0da33d1
--- /dev/null
+++ b/src/io.c
@@ -0,0 +1,64 @@
+#include <stdint.h>
+#include <stdio.h>
+
+#include "ch573/gpio.h"
+#include "ch573/uart.h"
+
+#include "io.h"
+
+#ifndef DEBUG_UART
+#define DEBUG_UART UART1
+#endif
+
+#define UART1 ch573_uart__uart1
+#define UART CH573_UART__UART_T_INTF
+
+#define GPIO_PORT_A ch573_gpio__gpio_port_a
+#define GPIO_PORT CH573_GPIO__GPIO_PORT_T_INTF
+
+#define gpio_usart1_tx_pin 9
+
+static int uart1_FILE_put(char ch, FILE* unused)
+{
+  if (ch == '\n') {
+    uart1_FILE_put('\r', unused);
+  }
+
+  while (!UART.lsr.thr_empty.get(UART1));
+  UART.thr.set(UART1, ch);
+
+  return 1;
+}
+
+static int uart1_FILE_get(FILE* f)
+{
+  return -1;
+}
+
+static int uart1_FILE_flush(FILE* f)
+{
+  return 0;
+}
+
+FILE _uart1_FILE = (FILE){
+    .put = uart1_FILE_put,
+    .get = uart1_FILE_get,
+    .flush = uart1_FILE_flush,
+    .flags = __SWR,
+};
+
+FILE* const stdout = &_uart1_FILE;
+
+void init_uart1_for_stdout(void)
+{
+  GPIO_PORT.dir.set(GPIO_PORT_A, DIR_OUT, gpio_usart1_tx_pin);
+  GPIO_PORT.pd_drv.set(GPIO_PORT_A, 0, gpio_usart1_tx_pin);
+
+  UART.div.set(UART1, 1);
+  UART.fcr.set(UART1, 0x07);
+  UART.ier.txd_en.set(UART1, ON);
+  UART.lcr.word_sz.set(UART1, WORD_SZ_8_BITS);
+
+  volatile uint32_t dl = (10 * 6400000 / 8 / BAUD_RATE + 5) / 10;
+  UART.dl.set(UART1, dl);
+}
diff --git a/src/main.c b/src/main.c
index d7eab9b..4cd54de 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,12 +1,9 @@
 #include <stdint.h>
 #include <stdio.h>
-#include <string.h>
 
 #include "ch573/gpio.h"
 #include "ch573/pwr.h"
 #include "ch573/uart.h"
-#include "isr_vector.h"
-#include "panic.h"
 
 #define GPIO_PORT_A ch573_gpio__gpio_port_a
 #define GPIO_PORT CH573_GPIO__GPIO_PORT_T_INTF
@@ -17,48 +14,6 @@
 #define PWR1 ch573_pwr__pwr_mgmt
 #define PWR CH573_PWR__PWR_MGMT_T_INTF
 
-void stack_dump(uint32_t*);
-void print_hex(uint32_t x);
-
-int uart1_FILE_put(char ch, FILE* f)
-{
-  if (ch == '\n') {
-    uart1_FILE_put('\r', f);
-  }
-
-  while (!UART.lsr.thr_empty.get(UART1));
-  UART.thr.set(UART1, ch);
-  return 1;
-}
-
-static int uart1_FILE_get(FILE* f)
-{
-  return -1;
-}
-
-static int uart1_FILE_flush(FILE* f)
-{
-  return 0;
-}
-
-FILE _uart1_FILE = (FILE){
-    .put = uart1_FILE_put,
-    .get = uart1_FILE_get,
-    .flush = uart1_FILE_flush,
-    .flags = __SWR,
-};
-
-FILE* const stdout = &_uart1_FILE;
-
-// FILE* const stdout = &_uart1_FILE;
-
-/*
- * Function which delays for a bit.
- */
-void delay(void);
-
-int main(void);
-
 uint32_t collatz(uint32_t n)
 {
   uint32_t c = 0;
@@ -75,118 +30,15 @@ uint32_t collatz(uint32_t n)
   return c;
 }
 
-void blink_n(int n)
-{
-  uint32_t bit = 1 << 8;
-  while (n > 0) {
-    GPIO_PORT.out.set(GPIO_PORT_A, OFF, 8);
-    delay();
-    GPIO_PORT.out.set(GPIO_PORT_A, ON, 8);
-    delay();
-    --n;
-  }
-}
-
-void delay(void)
-{
-  for (volatile uint32_t i = 0; i < 10000; ++i) {
-    asm volatile("");
-  }
-}
-
-volatile uint32_t deadbeef = 0xdeadbeef;
-
-#define gpio_usart1_tx_pin 9
-#define gpio_usart1_rx_pin 8
-
-const char* hello_world_static = "Hello, World!\r\n";
-
-#define BAUD_RATE 115200
-
-int test(char ch, ...);
-
-volatile int zero = 0;
-
-/* Main routine. This is called on_reset once everything else has been set up.
+/*
+ * Main routine. This is called on_reset once everything else has been set up.
  */
 int main(void)
 {
-  GPIO_PORT.dir.set(GPIO_PORT_A, DIR_OUT, gpio_usart1_tx_pin);
-  GPIO_PORT.pd_drv.set(GPIO_PORT_A, 0, gpio_usart1_tx_pin);
-
   GPIO_PORT.dir.set(GPIO_PORT_A, DIR_OUT, 8);
   GPIO_PORT.pd_drv.set(GPIO_PORT_A, 0, 8);
 
-  UART.div.set(UART1, 1);
-  UART.fcr.set(UART1, 0x07);
-  UART.ier.txd_en.set(UART1, ON);
-  UART.lcr.word_sz.set(UART1, WORD_SZ_8_BITS);
-
-  volatile uint32_t dl = (10 * 6400000 / 8 / BAUD_RATE + 5) / 10;
-  UART.dl.set(UART1, dl);
-
-  char buf[32] = {0};
-  volatile uint32_t i = 0xdeadbeef;
-
-  asm volatile("ebreak");
-
-
-  panic(0xdeadbeef);
-
-  stack_dump(&i);
-
-  print_hex(i);
-
-  stdout->put('a', NULL);
-  stdout->put('\n', NULL);
-  fputs("bulitin fputs\n", stdout);
-  puts("bulitin puts\n");
-
-  while (1) {
-    fprintf(stdout, "Hello! %% %s\n", "Josh");
-    fputs(buf, &_uart1_FILE);
-    delay();
-  }
-
-  // printf("Hello: %s\n", hello_world_static);
-  // printf("Here's deadbeef: %08x\n", deadbeef);
-
+  printf("Hello, %s!\n", "World");
   for (;;);
   return 0;
 }
-
-IRQ(systick)
-{
-  collatz(5);
-}
-
-#define putch(c) uart1_FILE_put(c, NULL)
-void print_binary(uint32_t x)
-{
-  int i = 0;
-  while (i < 32) {
-    int msb = (x & 0x80000000) >> 31;
-    x <<= 1;
-    if (msb) {
-      uart1_FILE_put('1', NULL);
-    } else {
-      uart1_FILE_put('0', NULL);
-    }
-    i++;
-  }
-}
-
-void print_hex(uint32_t x)
-{
-  int i = 0;
-  while (i < 8) {
-    int ms = (x & 0xf0000000) >> 28;
-    x <<= 4;
-    if (ms < 10) {
-      putch('0' + ms);
-    } else {
-      putch('a' + (ms - 10));
-    }
-    ++i;
-  }
-}