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- #ifndef LIBRM_H
- #define LIBRM_H
-
- FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
-
- /* Segment selectors as used in our protected-mode GDTs.
- *
- * Don't change these unless you really know what you're doing.
- */
- #define VIRTUAL_CS 0x08
- #define VIRTUAL_DS 0x10
- #define PHYSICAL_CS 0x18
- #define PHYSICAL_DS 0x20
- #define REAL_CS 0x28
- #define REAL_DS 0x30
- #define P2R_DS 0x38
- #define LONG_CS 0x40
-
- /* Calculate symbol address within VIRTUAL_CS or VIRTUAL_DS
- *
- * In a 64-bit build, we set the bases of VIRTUAL_CS and VIRTUAL_DS
- * such that truncating a .textdata symbol value to 32 bits gives a
- * valid 32-bit virtual address.
- *
- * The C code is compiled with -mcmodel=kernel and so we must place
- * all .textdata symbols within the negative 2GB of the 64-bit address
- * space. Consequently, all .textdata symbols will have the MSB set
- * after truncation to 32 bits. This means that a straightforward
- * R_X86_64_32 relocation record for the symbol will fail, since the
- * truncated symbol value will not correctly zero-extend to the
- * original 64-bit value.
- *
- * Using an R_X86_64_32S relocation record would work, but there is no
- * (sensible) way to generate these relocation records within 32-bit
- * or 16-bit code.
- *
- * The simplest solution is to generate an R_X86_64_32 relocation
- * record with an addend of (-0xffffffff00000000). Since all
- * .textdata symbols are within the negative 2GB of the 64-bit address
- * space, this addend acts to effectively truncate the symbol to 32
- * bits, thereby matching the semantics of the R_X86_64_32 relocation
- * records generated for 32-bit and 16-bit code.
- *
- * In a 32-bit build, this problem does not exist, and we can just use
- * the .textdata symbol values directly.
- */
- #ifdef __x86_64__
- #define VIRTUAL(address) ( (address) - 0xffffffff00000000 )
- #else
- #define VIRTUAL(address) (address)
- #endif
-
- #ifdef ASSEMBLY
-
- /**
- * Call C function from real-mode code
- *
- * @v function C function
- */
- .macro virtcall function
- pushl $VIRTUAL(\function)
- call virt_call
- .endm
-
- #else /* ASSEMBLY */
-
- #ifdef UACCESS_LIBRM
- #define UACCESS_PREFIX_librm
- #else
- #define UACCESS_PREFIX_librm __librm_
- #endif
-
- /**
- * Call C function from real-mode code
- *
- * @v function C function
- */
- #define VIRT_CALL( function ) \
- "pushl $( " _S2 ( VIRTUAL ( function ) ) " )\n\t" \
- "call virt_call\n\t"
-
- /* Variables in librm.S */
- extern const unsigned long virt_offset;
-
- /**
- * Convert physical address to user pointer
- *
- * @v phys_addr Physical address
- * @ret userptr User pointer
- */
- static inline __always_inline userptr_t
- UACCESS_INLINE ( librm, phys_to_user ) ( unsigned long phys_addr ) {
-
- /* In a 64-bit build, any valid physical address is directly
- * usable as a virtual address, since the low 4GB is
- * identity-mapped.
- */
- if ( sizeof ( physaddr_t ) > sizeof ( uint32_t ) )
- return phys_addr;
-
- /* In a 32-bit build, subtract virt_offset */
- return ( phys_addr - virt_offset );
- }
-
- /**
- * Convert user buffer to physical address
- *
- * @v userptr User pointer
- * @v offset Offset from user pointer
- * @ret phys_addr Physical address
- */
- static inline __always_inline unsigned long
- UACCESS_INLINE ( librm, user_to_phys ) ( userptr_t userptr, off_t offset ) {
- unsigned long addr = ( userptr + offset );
-
- /* In a 64-bit build, any virtual address in the low 4GB is
- * directly usable as a physical address, since the low 4GB is
- * identity-mapped.
- */
- if ( ( sizeof ( physaddr_t ) > sizeof ( uint32_t ) ) &&
- ( addr <= 0xffffffffUL ) )
- return addr;
-
- /* In a 32-bit build or in a 64-bit build with a virtual
- * address above 4GB: add virt_offset
- */
- return ( addr + virt_offset );
- }
-
- static inline __always_inline userptr_t
- UACCESS_INLINE ( librm, virt_to_user ) ( volatile const void *addr ) {
- return trivial_virt_to_user ( addr );
- }
-
- static inline __always_inline void *
- UACCESS_INLINE ( librm, user_to_virt ) ( userptr_t userptr, off_t offset ) {
- return trivial_user_to_virt ( userptr, offset );
- }
-
- static inline __always_inline userptr_t
- UACCESS_INLINE ( librm, userptr_add ) ( userptr_t userptr, off_t offset ) {
- return trivial_userptr_add ( userptr, offset );
- }
-
- static inline __always_inline off_t
- UACCESS_INLINE ( librm, userptr_sub ) ( userptr_t userptr,
- userptr_t subtrahend ) {
- return trivial_userptr_sub ( userptr, subtrahend );
- }
-
- static inline __always_inline void
- UACCESS_INLINE ( librm, memcpy_user ) ( userptr_t dest, off_t dest_off,
- userptr_t src, off_t src_off,
- size_t len ) {
- trivial_memcpy_user ( dest, dest_off, src, src_off, len );
- }
-
- static inline __always_inline void
- UACCESS_INLINE ( librm, memmove_user ) ( userptr_t dest, off_t dest_off,
- userptr_t src, off_t src_off,
- size_t len ) {
- trivial_memmove_user ( dest, dest_off, src, src_off, len );
- }
-
- static inline __always_inline int
- UACCESS_INLINE ( librm, memcmp_user ) ( userptr_t first, off_t first_off,
- userptr_t second, off_t second_off,
- size_t len ) {
- return trivial_memcmp_user ( first, first_off, second, second_off, len);
- }
-
- static inline __always_inline void
- UACCESS_INLINE ( librm, memset_user ) ( userptr_t buffer, off_t offset,
- int c, size_t len ) {
- trivial_memset_user ( buffer, offset, c, len );
- }
-
- static inline __always_inline size_t
- UACCESS_INLINE ( librm, strlen_user ) ( userptr_t buffer, off_t offset ) {
- return trivial_strlen_user ( buffer, offset );
- }
-
- static inline __always_inline off_t
- UACCESS_INLINE ( librm, memchr_user ) ( userptr_t buffer, off_t offset,
- int c, size_t len ) {
- return trivial_memchr_user ( buffer, offset, c, len );
- }
-
-
- /******************************************************************************
- *
- * Access to variables in .data16 and .text16
- *
- */
-
- extern char * const data16;
- extern char * const text16;
-
- #define __data16( variable ) \
- __attribute__ (( section ( ".data16" ) )) \
- _data16_ ## variable __asm__ ( #variable )
-
- #define __data16_array( variable, array ) \
- __attribute__ (( section ( ".data16" ) )) \
- _data16_ ## variable array __asm__ ( #variable )
-
- #define __bss16( variable ) \
- __attribute__ (( section ( ".bss16" ) )) \
- _data16_ ## variable __asm__ ( #variable )
-
- #define __bss16_array( variable, array ) \
- __attribute__ (( section ( ".bss16" ) )) \
- _data16_ ## variable array __asm__ ( #variable )
-
- #define __text16( variable ) \
- __attribute__ (( section ( ".text16.data" ) )) \
- _text16_ ## variable __asm__ ( #variable )
-
- #define __text16_array( variable, array ) \
- __attribute__ (( section ( ".text16.data" ) )) \
- _text16_ ## variable array __asm__ ( #variable )
-
- #define __use_data16( variable ) \
- ( * ( ( typeof ( _data16_ ## variable ) * ) \
- & ( data16 [ ( size_t ) & ( _data16_ ## variable ) ] ) ) )
-
- #define __use_text16( variable ) \
- ( * ( ( typeof ( _text16_ ## variable ) * ) \
- & ( text16 [ ( size_t ) & ( _text16_ ## variable ) ] ) ) )
-
- #define __from_data16( pointer ) \
- ( ( unsigned int ) \
- ( ( ( void * ) (pointer) ) - ( ( void * ) data16 ) ) )
-
- #define __from_text16( pointer ) \
- ( ( unsigned int ) \
- ( ( ( void * ) (pointer) ) - ( ( void * ) text16 ) ) )
-
- /* Variables in librm.S, present in the normal data segment */
- extern uint16_t rm_sp;
- extern uint16_t rm_ss;
- extern const uint16_t __text16 ( rm_cs );
- #define rm_cs __use_text16 ( rm_cs )
- extern const uint16_t __text16 ( rm_ds );
- #define rm_ds __use_text16 ( rm_ds )
-
- extern uint16_t copy_user_to_rm_stack ( userptr_t data, size_t size );
- extern void remove_user_from_rm_stack ( userptr_t data, size_t size );
-
- /* CODE_DEFAULT: restore default .code32/.code64 directive */
- #ifdef __x86_64__
- #define CODE_DEFAULT ".code64"
- #else
- #define CODE_DEFAULT ".code32"
- #endif
-
- /* TEXT16_CODE: declare a fragment of code that resides in .text16 */
- #define TEXT16_CODE( asm_code_str ) \
- ".section \".text16\", \"ax\", @progbits\n\t" \
- ".code16\n\t" \
- asm_code_str "\n\t" \
- CODE_DEFAULT "\n\t" \
- ".previous\n\t"
-
- /* REAL_CODE: declare a fragment of code that executes in real mode */
- #define REAL_CODE( asm_code_str ) \
- "push $1f\n\t" \
- "call real_call\n\t" \
- TEXT16_CODE ( "\n1:\n\t" \
- asm_code_str \
- "\n\t" \
- "ret\n\t" )
-
- /* PHYS_CODE: declare a fragment of code that executes in flat physical mode */
- #define PHYS_CODE( asm_code_str ) \
- "push $1f\n\t" \
- "call phys_call\n\t" \
- ".section \".text.phys\", \"ax\", @progbits\n\t"\
- ".code32\n\t" \
- "\n1:\n\t" \
- asm_code_str \
- "\n\t" \
- "ret\n\t" \
- CODE_DEFAULT "\n\t" \
- ".previous\n\t"
-
- /** Number of interrupts */
- #define NUM_INT 256
-
- /** A 32-bit interrupt descriptor table register */
- struct idtr32 {
- /** Limit */
- uint16_t limit;
- /** Base */
- uint32_t base;
- } __attribute__ (( packed ));
-
- /** A 64-bit interrupt descriptor table register */
- struct idtr64 {
- /** Limit */
- uint16_t limit;
- /** Base */
- uint64_t base;
- } __attribute__ (( packed ));
-
- /** A 32-bit interrupt descriptor table entry */
- struct interrupt32_descriptor {
- /** Low 16 bits of address */
- uint16_t low;
- /** Code segment */
- uint16_t segment;
- /** Unused */
- uint8_t unused;
- /** Type and attributes */
- uint8_t attr;
- /** High 16 bits of address */
- uint16_t high;
- } __attribute__ (( packed ));
-
- /** A 64-bit interrupt descriptor table entry */
- struct interrupt64_descriptor {
- /** Low 16 bits of address */
- uint16_t low;
- /** Code segment */
- uint16_t segment;
- /** Unused */
- uint8_t unused;
- /** Type and attributes */
- uint8_t attr;
- /** Middle 16 bits of address */
- uint16_t mid;
- /** High 32 bits of address */
- uint32_t high;
- /** Reserved */
- uint32_t reserved;
- } __attribute__ (( packed ));
-
- /** Interrupt descriptor is present */
- #define IDTE_PRESENT 0x80
-
- /** Interrupt descriptor 32-bit interrupt gate type */
- #define IDTE_TYPE_IRQ32 0x0e
-
- /** Interrupt descriptor 64-bit interrupt gate type */
- #define IDTE_TYPE_IRQ64 0x0e
-
- /** An interrupt vector
- *
- * Each interrupt vector comprises an eight-byte fragment of code:
- *
- * 50 pushl %eax (or pushq %rax in long mode)
- * b0 xx movb $INT, %al
- * e9 xx xx xx xx jmp interrupt_wrapper
- */
- struct interrupt_vector {
- /** "push" instruction */
- uint8_t push;
- /** "movb" instruction */
- uint8_t movb;
- /** Interrupt number */
- uint8_t intr;
- /** "jmp" instruction */
- uint8_t jmp;
- /** Interrupt wrapper address offset */
- uint32_t offset;
- /** Next instruction after jump */
- uint8_t next[0];
- } __attribute__ (( packed ));
-
- /** "push %eax" instruction */
- #define PUSH_INSN 0x50
-
- /** "movb" instruction */
- #define MOVB_INSN 0xb0
-
- /** "jmp" instruction */
- #define JMP_INSN 0xe9
-
- extern void set_interrupt_vector ( unsigned int intr, void *vector );
-
- /** A page table */
- struct page_table {
- /** Page address and flags */
- uint64_t page[512];
- };
-
- /** Page flags */
- enum page_flags {
- /** Page is present */
- PAGE_P = 0x01,
- /** Page is writable */
- PAGE_RW = 0x02,
- /** Page is accessible by user code */
- PAGE_US = 0x04,
- /** Page-level write-through */
- PAGE_PWT = 0x08,
- /** Page-level cache disable */
- PAGE_PCD = 0x10,
- /** Page is a large page */
- PAGE_PS = 0x80,
- /** Page is the last page in an allocation
- *
- * This bit is ignored by the hardware. We use it to track
- * the size of allocations made by ioremap().
- */
- PAGE_LAST = 0x800,
- };
-
- /** The I/O space page table */
- extern struct page_table io_pages;
-
- /** I/O page size
- *
- * We choose to use 2MB pages for I/O space, to minimise the number of
- * page table entries required.
- */
- #define IO_PAGE_SIZE 0x200000UL
-
- /** I/O page base address
- *
- * We choose to place I/O space immediately above the identity-mapped
- * 32-bit address space.
- */
- #define IO_BASE ( ( void * ) 0x100000000ULL )
-
- #endif /* ASSEMBLY */
-
- #endif /* LIBRM_H */
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