diff options
Diffstat (limited to 'translation_table_descriptors.h')
| -rw-r--r-- | translation_table_descriptors.h | 129 |
1 files changed, 86 insertions, 43 deletions
diff --git a/translation_table_descriptors.h b/translation_table_descriptors.h index 8f92473..981c3c7 100644 --- a/translation_table_descriptors.h +++ b/translation_table_descriptors.h @@ -1,3 +1,6 @@ +#ifndef TRANSLATION_TABLE_DESCRIPTORS_H +#define TRANSLATION_TABLE_DESCRIPTORS_H + #include <stdint.h> // ARM lets you choose between 32-bit abd 64-bit translation table @@ -11,6 +14,33 @@ // meanings depending on settings in coprocessor registers... (yeah, ARM // looks a bit messy... all for backward compatibility, i guess) + +////// Here are the definitions for short-format descriptors + +//// short-format page table descriptor + +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; + + +//// short-format section descriptor + typedef struct { uint32_t PXN : 1; // bit 0 @@ -28,56 +58,26 @@ 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; -// How AP[2:0] is used depends on settings in SCTLR.AFE - -// Meaning of #define'd names below: -// RW - read-write -// RO - read-only -// PL1 - a given permission applies to privilege level PL1 -// PL2 - a given permission applies to privilege level PL2 -// ALL - a given permission applies to both privilege levels -// If only a permission for one privilege level is given in the name, -// it means the other one has no access. - -// When SCTLR.AFE is 0 (access flag not used) and short-format -// descritor table is used, the following access permission control -// schema for AP[2:0] is used: -#define AP_2_0_MODEL_NO_ACCESS 0b000 -#define AP_2_0_MODEL_RW_PL1 0b001 -#define AP_2_0_MODEL_RW_PL1_RO_PL0 0b010 -#define AP_2_0_MODEL_RW_ALL 0b011 -#define AP_2_0_MODEL_RESERVED 0b100 -#define AP_2_0_MODEL_RO_PL1 0b101 -#define AP_2_0_MODEL_RO_ALL_DEPRECATED 0b110 // use 0b111 instead -#define AP_2_0_MODEL_RO_ALL 0b111 // reserved in VMSAv6 -// TODO: the #define's of RO_ALL and reserved could be done -// conditionally depending on the VMSA version available (either give -// the programmer #including this the possibility to #define their -// VMSA version or assume the VMSA version respective to the ARM -// version we're compiling against) - -// Values for bit18, that determines whether a descriptor describes -// section or supersection: -#define DESCRIBES_SECTION 0b0 -#define DESCRIBES_SUPERSECTION 0b1 +//// short-format supersection descriptor typedef struct { @@ -99,7 +99,7 @@ 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 @@ -116,17 +116,59 @@ typedef struct #define SUPERSECTION_BASE_ADDRESS_31_24 PA_31_24 } short_supersection_descriptor_t; + +//// possible access permission field values + +// How AP[2:0] is used depends on settings in SCTLR.AFE + +// Meaning of #define'd names below: +// RW - read-write +// RO - read-only +// PL1 - a given permission applies to privilege level PL1 +// PL2 - a given permission applies to privilege level PL2 +// ALL - a given permission applies to both privilege levels +// If only a permission for one privilege level is given in the name, +// it means the other one has no access. + +// When SCTLR.AFE is 0 (access flag not used) and short-format +// descritor table is used, the following access permission control +// schema for AP[2:0] is used: +#define AP_2_0_MODEL_NO_ACCESS 0b000 +#define AP_2_0_MODEL_RW_PL1 0b001 +#define AP_2_0_MODEL_RW_PL1_RO_PL0 0b010 +#define AP_2_0_MODEL_RW_ALL 0b011 +#define AP_2_0_MODEL_RESERVED 0b100 +#define AP_2_0_MODEL_RO_PL1 0b101 +#define AP_2_0_MODEL_RO_ALL_DEPRECATED 0b110 // use 0b111 instead +#define AP_2_0_MODEL_RO_ALL 0b111 // reserved in VMSAv6 +// TODO: the #define's of RO_ALL and reserved could be done +// conditionally depending on the VMSA version available (either give +// the programmer #including this the possibility to #define their +// VMSA version or assume the VMSA version respective to the ARM +// version we're compiling against) + + +//// Values for bit18, that determines whether a descriptor describes +// section or supersection: +#define DESCRIBES_SECTION 0b0 +#define DESCRIBES_SUPERSECTION 0b1 + + +//// short-format descriptor generic type + typedef union { uint32_t raw; - uint8_t descriptor_type; - + uint8_t descriptor_type : 2; + + short_page_table_descriptor_t page_table_fields; short_section_descriptor_t section_fields; short_supersection_descriptor_t supersection_fields; - // more to come here (e.g. short_supersection_descriptor_t) -} short_descriptor_t; +} short_descriptor_lvl1_t; + + +//// possible values of descriptor_type field: -// possible values of descriptor_type field: #define SHORT_DESCRIPTOR_INVALID 0b00 #define SHORT_DESCRIPTOR_PAGE_TABLE 0b01 #define SHORT_DESCRIPTOR_SECTION_OR_SUPERSECTION 0b10 @@ -135,3 +177,4 @@ typedef union // 0b11 should not be used #define SHORT_DESCRIPTOR_RESERVED 0b11 +#endif // TRANSLATION_TABLE_DESCRIPTORS_H |