Pass the hart ID on start_kernel instead

Instead of storing the hard ID as given by the bootloader into a C
variable, pass it directly into the 'start_kernel' function since we
don't need to tamper the value as originally laid out on the 'a0'
register.

Signed-off-by: Miquel Sabaté Solà <mikisabate@gmail.com>

2 files changed, 4 insertions, 9 deletions

diff --git a/include/fbos/init.h b/include/fbos/init.h
index f253645..592a7f1 100644
--- a/include/fbos/init.h
+++ b/include/fbos/init.h
@@ -25,11 +25,6 @@
 // Instantiated in kernel/main.c
 extern atomic32_t hart_lottery;
 
-// ID of the hart that is running the show.
-//
-// Instantiated in kernel/main.c
-extern uint32_t hart_id;
-
 // Tracks the amount of seconds that have elapsed since activating timer
 // interrupts.
 //
@@ -52,9 +47,9 @@ void setup_interrupts(void);
 
 /*
  * This is the main entry point of the kernel after head.S is done. This
- * function can (and will) assume that everything has been reset and that we can
- * start the whole thing.
+ * function expects exactly two arguments, which are exactly the same as they
+ * are passed to the `_start` function in kernel/head.S by the bootloader.
  */
-void start_kernel(void *dtb);
+void start_kernel(uint64_t hart_id, void *dtb);
 
 #endif /* __FBOS_INIT_H */
diff --git a/include/fbos/printk.h b/include/fbos/printk.h
index d6ca71e..d118734 100644
--- a/include/fbos/printk.h
+++ b/include/fbos/printk.h
@@ -13,7 +13,7 @@
 extern void die(const char *const message);
 
 // Print the given number as a single digit.
-extern void print_digit(uint32_t digit);
+extern void print_digit(uint64_t digit);
 
 // Print the given message.
 extern void printk(const char *const message);