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

9 files changed, 42 insertions, 54 deletions

diff --git a/src/arm/PL1/kernel/interrupt_vector.S b/src/arm/PL1/kernel/interrupt_vector.S
index 1ec80f7..3afc193 100644
--- a/src/arm/PL1/kernel/interrupt_vector.S
+++ b/src/arm/PL1/kernel/interrupt_vector.S
@@ -8,9 +8,12 @@ _interrupt_vectors:
 	b irq_handler_caller
 	b fiq_handler_caller
 	
+// from what I've heard, reset is never used on the Pi;
+// in our case it should run once - when stage1 of the kernel
+// jumps to stage2
 reset_handler_caller:
 	ldr sp, =_supervisor_stack_top
-	ldr r5, =reset_handler
+	ldr r5, =setup
 	bx r5
 	
 undef_handler_caller:
diff --git a/src/arm/PL1/kernel/interrupts.c b/src/arm/PL1/kernel/interrupts.c
index 5695e6f..6f61615 100644
--- a/src/arm/PL1/kernel/interrupts.c
+++ b/src/arm/PL1/kernel/interrupts.c
@@ -4,17 +4,6 @@
 #include "armclock.h"
 #include "scheduler.h"
 
-// defined in setup.c
-void __attribute__((noreturn)) setup(void);
-
-// from what I've heard, reset is never used on the Pi;
-// in our case it should run once - when stage1 of the kernel
-// jumps to stage2
-void reset_handler(void)
-{
-  setup();
-}
-
 void undefined_instruction_vector(void)
 {
   error("Undefined instruction occured");
@@ -85,6 +74,7 @@ void irq_handler(uint32_t regs[14])
 
       if (read_SPSR().fields.PSR_MODE_4_0 != MODE_USER)
 	{
+	  // TODO set supervisor mode's stack pointer
 	  write_SPSR(PL1_PSR);
 	  asm volatile("mov lr, %0\n\r"
 		       "subs pc, lr, #0" ::
diff --git a/src/arm/PL1/kernel/kernel.ld b/src/arm/PL1/kernel/kernel.ld
index 3130634..5ccce06 100644
--- a/src/arm/PL1/kernel/kernel.ld
+++ b/src/arm/PL1/kernel/kernel.ld
@@ -16,7 +16,7 @@ ENTRY(_boot) /* defined in boot.S; qemu needs it to run elf file */
 SECTIONS
 {
 
-	. = 0x8000;
+	. = 0x8000; /* irrelevant */
 
 	__start = .;
 	.kernel_stage1 :
diff --git a/src/arm/PL1/kernel/kernel_stage2.ld b/src/arm/PL1/kernel/kernel_stage2.ld
index 9411ca2..2858355 100644
--- a/src/arm/PL1/kernel/kernel_stage2.ld
+++ b/src/arm/PL1/kernel/kernel_stage2.ld
@@ -1,4 +1,4 @@
-/* This sesond stage of the kernel is run from address 0x0 */
+/* This second stage of the kernel is run from address 0x0 */
 
 TRANSLATION_TABLE_SIZE = 4096 * 4;
 SECTIONS_LIST_SIZE = 4096 * 8;
diff --git a/src/arm/PL1/kernel/ramfs.c b/src/arm/PL1/kernel/ramfs.c
index cc66b4c..ed3ff73 100644
--- a/src/arm/PL1/kernel/ramfs.c
+++ b/src/arm/PL1/kernel/ramfs.c
@@ -3,32 +3,7 @@
 
 #include <stdint.h>
 #include "ramfs.h"
-
-static int strcmp(char const *str1, char const *str2)
-{
-  while (1)
-    {
-      int c1 = (unsigned char) *str1, c2 = (unsigned char) *str2;
-      
-      if (!c1 && !c2)
-	return 0;
-
-      if (c1 != c2)
-	return c1 - c2;
-
-      str1++; str2++;
-    }
-}
-
-static uint32_t strlen(char const *str1)
-{
-  uint32_t len = 0;
-
-  while (str1[len])
-    len++;
-
-  return len;
-}
+#include "strings.h"
 
 static inline char *align4(char *addr)
 {
diff --git a/src/arm/PL1/kernel/scheduler.c b/src/arm/PL1/kernel/scheduler.c
index 141ba1d..1db8078 100644
--- a/src/arm/PL1/kernel/scheduler.c
+++ b/src/arm/PL1/kernel/scheduler.c
@@ -24,7 +24,7 @@ _Bool waiting_for_input = 0;
 _Bool waiting_for_output = 0;
 char waiting_output;
 
-// 0 is kernel code in system mode is being run
+// 0 if kernel code in system mode is being run
 // 1 if our process is being run
 // later when we have many processes and this will hold process id
 uint32_t current_process;
@@ -126,7 +126,7 @@ void __attribute__((noreturn)) schedule(void)
   
       write_CPSR(new_CPSR);
       
-      asm volatile("wfi");
+      asm volatile("wfi" ::: "memory");
 
       __builtin_unreachable();
     }
diff --git a/src/arm/PL1/loader/loader.ld b/src/arm/PL1/loader/loader.ld
index 711fcbf..7ab846a 100644
--- a/src/arm/PL1/loader/loader.ld
+++ b/src/arm/PL1/loader/loader.ld
@@ -2,7 +2,7 @@ ENTRY(_boot)
  
 SECTIONS
 {
-	/* see linker.ld for details */
+	/* irrelevant, see linker.ld for details */
 	. = 0x2000000;
 
 	__start = .;
diff --git a/src/arm/common/strings.c b/src/arm/common/strings.c
index 368d7dc..0c7a73b 100644
--- a/src/arm/common/strings.c
+++ b/src/arm/common/strings.c
@@ -69,15 +69,6 @@ void uint32_to_hexstringt(uint32_t number, char buf[9])
   trim_0s(buf);
 }
 
-size_t strlen(char string[])
-{
-  size_t len;
-
-  for (len = 0; string[len]; len++);
-
-  return len;
-}
-
 void memcpy(void *dst, void *src, size_t nbytes)
 {
   size_t iter;
@@ -117,3 +108,30 @@ char *strcat(char *dst, const char *src)
 
   return dst;
 }
+
+int strcmp(char const *str1, char const *str2)
+{
+  while (1)
+    {
+      int c1 = (unsigned char) *str1, c2 = (unsigned char) *str2;
+      
+      if (!c1 && !c2)
+	return 0;
+
+      if (c1 != c2)
+	return c1 - c2;
+
+      str1++; str2++;
+    }
+}
+
+size_t strlen(char const *str1)
+{
+  size_t len = 0;
+
+  while (str1[len])
+    len++;
+
+  return len;
+}
+
diff --git a/src/arm/common/strings.h b/src/arm/common/strings.h
index aff0533..67c1ab7 100644
--- a/src/arm/common/strings.h
+++ b/src/arm/common/strings.h
@@ -22,12 +22,14 @@ void uint32_to_decstringt(uint32_t number, char buf[11]);
 
 void uint32_to_hexstringt(uint32_t number, char buf[9]);
 
-size_t strlen(char string[]);
-
 void memcpy(void *dst, void *src, size_t nbytes);
   
 void *memset(void *s, int c, size_t n);
 
 char *strcat(char *dst, const char *src);
   
+int strcmp(char const *str1, char const *str2);
+
+size_t strlen(char const *str1);
+
 #endif // STRINGS_H