Merge branch 'bob' of https://repo.or.cz/RPi-MMU-example into alice

# Conflicts:
#	.gitignore
#	PL0_test.ld
#	demo_functionality.c
#	interrupt_vector.S
#	interrupts.c
#	kernel.c
#	memory.h

1 files changed, 119 insertions, 0 deletions

diff --git a/setup.c b/setup.c
new file mode 100644
index 0000000..ad01720
--- /dev/null
+++ b/setup.c
@@ -0,0 +1,119 @@
+#include "uart.h"
+#include "io.h"
+#include "demo_functionality.h"
+#include "paging.h"
+#include "atags.h"
+// for POWER_OF_2() macro... perhaps the macro should be moved
+#include "memory.h"
+#include "armclock.h"
+
+void setup(uint32_t r0, uint32_t machine_type,
+	   struct atag_header *atags)
+{
+  uart_init();
+
+  // When we attach screen session after loading kernel with socat
+  // we miss kernel's greeting... So we'll make the kernel wait for
+  // one char we're going to send from within screen
+  getchar();
+  
+  puts("Hello, kernel World!");
+
+  prints("ARM machine type: 0x"); printhext(machine_type); puts("");
+
+  uint32_t memory_size = 0;
+  
+  // value 3 introduced by stage1 code means no atags was found
+  if (r0 == 3)
+    puts("No ATAGS was found!");
+  else
+    {
+      prints("ATAGS copied to 0x");
+      printhex((uint32_t) atags); puts("");
+
+      puts("__ ATAGS contents __");
+
+      print_atags(atags);
+
+      puts("__ end of ATAGS contents __");
+
+      memory_size = find_memory_size(atags);
+    }
+
+  if (memory_size)
+    {
+      char *unit;
+      uint32_t size_in_unit;
+
+      if (memory_size % POWER_OF_2(10))
+	{
+	  unit = "B";
+	  size_in_unit = memory_size;
+	}
+      else if (memory_size % POWER_OF_2(20))
+	{
+	  unit = "KB";
+	  size_in_unit = memory_size / POWER_OF_2(10);
+	}
+      else if (memory_size % POWER_OF_2(30))
+	{
+	  unit = "MB";
+	  size_in_unit = memory_size / POWER_OF_2(20);
+	}
+      else
+	{
+	  unit = "GB";
+	  size_in_unit = memory_size / POWER_OF_2(30);
+	}
+      
+      prints("memory available: ");
+      printdect(size_in_unit); puts(unit);
+    }
+  else
+    {
+      // Most Pis have more, but qemu might give us little
+      puts("Couldn't determine available memory - assuming 192MB");
+      memory_size = 192 * POWER_OF_2(20);
+    }
+
+  // assume we need at least one section for PL0
+  if (memory_size < PRIVILEGED_MEMORY_END + SECTION_SIZE)
+    {
+      puts("Not enough memory to continue");
+      while (1);
+    }
+  
+  // prints some info
+  demo_paging_support();
+
+  // prints some info
+  demo_current_mode();
+
+  setup_pager_structures(memory_size);
+  
+  // prints some info and sets upp translation table, turns on MMU
+  setup_flat_map();
+
+  // prints some info and sets up a section for PL0 code,
+  // loads a blob there 
+  demo_setup_PL0();
+
+  // sets some general settings for arm timer
+  armclk_init();
+
+  // turns on irq from arm timer
+  armclk_enable_timer_irq();
+
+  // jumps to unprivileged code... never, ever, ever returns
+  demo_go_unprivileged();
+  
+  while (1)
+    {
+      char c = getchar();
+
+      if (c == '\r')
+	putchar('\n');
+
+      putchar(c);
+    }
+}