represent page table descriptor as struct, fix #define conflicts between translation_table_descriptors.h and cp_regs.h, fix name of one #define'd field of section descriptors

3 files changed, 39 insertions, 16 deletions

diff --git a/cp_regs.h b/cp_regs.h
index 98a8bb8..2bc6c9f 100644
--- a/cp_regs.h
+++ b/cp_regs.h
@@ -98,14 +98,14 @@ typedef union
 
     // i'm not sure 'interprocess region bits' is the right name,
     // I'm just guessing (by analogy to RGN -> region bits)
-#define CACHEABLE_BIT                  C
-#define INTERPROCESS_REGION_BITS_1     IRGN_1
-#define SHAREABLE_BIT                  S
-#define IMPLEMENTATION_DEFINED_BIT     IMP
-#define REGION_BITS_1_0                RGN
-#define INTERPROCESS_REGION_BITS_0     IRGN_0
-#define NON_OUTER_SHAREABLE_BIT        NOS
-#define TRANSLATION_TABLE_BASE_ADDRESS Bits_31_14
+#define TTBR_CACHEABLE_BIT                  C
+#define TTBR_INTERPROCESS_REGION_BITS_1     IRGN_1
+#define TTBR_SHAREABLE_BIT                  S
+#define TTBR_IMPLEMENTATION_DEFINED_BIT     IMP
+#define TTBR_REGION_BITS_1_0                RGN
+#define TTBR_INTERPROCESS_REGION_BITS_0     IRGN_0
+#define TTBR_NON_OUTER_SHAREABLE_BIT        NOS
+#define TTBR_TRANSLATION_TABLE_BASE_ADDRESS Bits_31_14
   } fields;
 } TTBR_t;
 
diff --git a/kernel.c b/kernel.c
index 8d2fdef..765b770 100644
--- a/kernel.c
+++ b/kernel.c
@@ -96,7 +96,7 @@ void kernel_main(uint32_t r0, uint32_t r1, uint32_t atags)
 	.SECTION_OR_SUPERSECTION_BIT = DESCRIBES_SECTION,
 	.ACCESS_PERMISSIONS_2        = AP_2_0_MODEL_RW_PL1 >> 2,
 	.ACCESS_PERMISSIONS_1_0      = AP_2_0_MODEL_RW_PL1 & 0b011,
-	.DESCRIPTOR_TYPE_2           =
+	.DESCRIPTOR_TYPE_1           =
 	   SHORT_DESCRIPTOR_SECTION_OR_SUPERSECTION >> 1,
 	// rest of fields are 0s
       };
@@ -162,7 +162,7 @@ void kernel_main(uint32_t r0, uint32_t r1, uint32_t atags)
   // Now do stuff with TTBR0
   TTBR_t TTBR0;
   TTBR0.raw = 0;
-  TTBR0.fields.TRANSLATION_TABLE_BASE_ADDRESS =
+  TTBR0.fields.TTBR_TRANSLATION_TABLE_BASE_ADDRESS =
     translation_table_base >> 14;
   // rest of TTBR0 remains 0s
   
diff --git a/translation_table_descriptors.h b/translation_table_descriptors.h
index 8f92473..975ab61 100644
--- a/translation_table_descriptors.h
+++ b/translation_table_descriptors.h
@@ -11,6 +11,27 @@
 // meanings depending on settings in coprocessor registers... (yeah, ARM
 // looks a bit messy... all for backward compatibility, i guess)
 
+
+typedef struct
+{
+  uint32_t Bits_1_0   : 1;  // bits 1:0
+  uint32_t PXN        : 1;  // bit  2
+  uint32_t NS         : 1;  // bit  3
+  uint32_t SBZ        : 1;  // bit  4
+  uint32_t Domain_3_0 : 4;  // bits 8:5
+  uint32_t Bit_9      : 1;  // bit  9
+  uint32_t Bits_31_10 : 22; // bits 31:10
+#define DESCRIPTOR_TYPE_1_0           Bits_1_0
+#define PRIVILEGED_EXECUTE_NEVER_BIT  PXN
+#define NON_SECURE_BIT                NS
+  // me thinks SBZ means "should be zero",
+  // but me sees no point #defining it
+#define DOMAIN_3_0                    Domain_3_0
+#define IMPLEMENTATION_DEFINED_BIT    Bit_9
+#define PAGE_TABLE_BASE_ADDRESS_31_10 Bits_31_10
+} short_page_table_descriptor_t;
+
+
 typedef struct
 {
   uint32_t PXN        : 1;  // bit  0
@@ -28,20 +49,21 @@ typedef struct
   uint32_t Bit_18     : 1;  // bit  18
   uint32_t NS         : 1;  // bit  19
   uint32_t PA_31_20   : 12; // bits 31:20
-#define PRIVILEGED_EXECUTE_NEVER_BIT PXN
-#define DESCRIPTOR_TYPE_2            Bit_1
+  // some of these are already defined the same for page table
+  //#define PRIVILEGED_EXECUTE_NEVER_BIT PXN
+#define DESCRIPTOR_TYPE_1            Bit_1
 #define BUFFERABLE_BIT               B
 #define CACHEABLE_BIT                C
 #define EXECUTE_NEVER_BIT            XN
-#define DOMAIN_3_0                   Domain_3_0
-#define IMPLEMENTATION_DEFINED_BIT   Bit_9
+  //#define DOMAIN_3_0                   Domain_3_0
+  //#define IMPLEMENTATION_DEFINED_BIT   Bit_9
 #define ACCESS_PERMISSIONS_1_0       AP_1_0
 #define TYPE_EXTENSION_2_0           TEX_2_0
 #define ACCESS_PERMISSIONS_2         AP_2
 #define SHAREABLE_BIT                S
 #define NON_GLOBAL_BIT               nG
 #define SECTION_OR_SUPERSECTION_BIT  Bit_18
-#define NON_SECURE_BIT               NS
+  //#define NON_SECURE_BIT               NS
 #define SECTION_BASE_ADDRESS_31_20   PA_31_20
 } short_section_descriptor_t;
 
@@ -79,6 +101,7 @@ typedef struct
 #define DESCRIBES_SECTION      0b0
 #define DESCRIBES_SUPERSECTION 0b1
 
+
 typedef struct
 {
   uint32_t PXN        : 1; // bit  0
@@ -99,7 +122,7 @@ typedef struct
   uint32_t PA_31_24   : 8; // bits 31:24
   // most of these are already defined the same for section
   //#define PRIVILEGED_EXECUTE_NEVER_BIT    PXN
-  //#define DESCRIPTOR_TYPE_2               Bit_1
+  //#define DESCRIPTOR_TYPE_1               Bit_1
   //#define BUFFERABLE_BIT                  B
   //#define CACHEABLE_BIT                   C
   //#define EXECUTE_NEVER_BIT               XN