N64 bootup and cache interfaces. More...

Files
file	n64sys.c
	N64 System Interface.

file	cop0.h
	N64 COP0 Interface.

file	cop1.h
	N64 COP1 Interface.

file	n64sys.h
	N64 System Interface.

Macros
#define	cache_op(op, linesize)
	Helper macro to perform cache refresh operations. More...

#define	TV_TYPE_LOC 0x80000300
	Memory location to read which determines the TV type.

#define	C0_COUNT()
	Read the COP0 Count register (see also TICKS_READ). More...

#define	C0_WRITE_COUNT(x)
	Write the COP0 Count register. More...

#define	C0_COMPARE()
	Read the COP0 Compare register. More...

#define	C0_WRITE_COMPARE(x)
	Write the COP0 Compare register. More...

#define	C0_STATUS()
	Read the COP0 Status register. More...

#define	C0_WRITE_STATUS(x)
	Write the COP0 Status register. More...

#define	C0_CAUSE()
	Returns the COP0 register $13 (Cause Register) More...

#define	C0_WRITE_CAUSE(x)
	Write the COP0 register $13 (Cause register) More...

#define	C0_BADVADDR()
	Returns the COP0 register $8 (BadVAddr) More...

#define	C0_EPC()
	Read the COP0 register $14 (EPC) More...

#define	C0_INDEX()
	Read the COP0 INDEX register. More...

#define	C0_WRITE_INDEX(x) asm volatile("mtc0 %0,$0; nop; nop"::"r"(x))
	Write the COP0 INDEX register. More...

#define	C0_ENTRYHI()
	Read the COP0 ENTRYHI register. More...

#define	C0_WRITE_ENTRYHI(x) asm volatile("mtc0 %0,$10; nop; nop"::"r"(x))
	Write the COP0 ENTRYHI register. More...

#define	C0_ENTRYLO0()
	Read the COP0 ENTRYLO0 register. More...

#define	C0_WRITE_ENTRYLO0(x) asm volatile("mtc0 %0,$2; nop; nop"::"r"(x))
	Write the COP0 ENTRYLO0 register. More...

#define	C0_ENTRYLO1()
	Read the COP0 ENTRYLO1 register. More...

#define	C0_WRITE_ENTRYLO1(x) asm volatile("mtc0 %0,$3; nop; nop"::"r"(x))
	Write the COP0 ENTRYLO1 register. More...

#define	C0_PAGEMASK()
	Read the COP0 PAGEMASK register. More...

#define	C0_WRITE_PAGEMASK(x) asm volatile("mtc0 %0,$5; nop; nop"::"r"(x))
	Write the COP0 PAGEMASK register. More...

#define	C0_WIRED()
	Read the COP0 WIRED register. More...

#define	C0_WATCHLO()
	Read the COP0 WATCHLO register. More...

#define	C0_WRITE_WATCHLO(x) asm volatile("mtc0 %0,$18"::"r"(x))
	Write the COP0 WATCHLO register. More...

#define	C0_WRITE_WIRED(x) asm volatile("mtc0 %0,$6; nop; nop"::"r"(x))
	Write the COP0 WIRED register. More...

#define	C0_STATUS_IE 0x00000001
	Status: interrupt enable.

#define	C0_STATUS_EXL 0x00000002
	Status: within exception.

#define	C0_STATUS_ERL 0x00000004
	Status: within error.

#define	C0_CAUSE_BD 0x80000000
	Cause: exception triggered in delay slot.

#define	C0_CAUSE_CE 0x30000000
	Cause: coprocessor exception.

#define	C0_CAUSE_EXC_CODE 0x0000007C
	Cause: exception code.

#define	C0_INTERRUPT_0 0x00000100
	Status/Cause: SW interrupt 0.

#define	C0_INTERRUPT_1 0x00000200
	Status/Cause: SW interrupt 1.

#define	C0_INTERRUPT_2 0x00000400
	Status/Cause: HW interrupt 2 (RCP)

#define	C0_INTERRUPT_3 0x00000800
	Status/Cause: HW interrupt 3.

#define	C0_INTERRUPT_4 0x00001000
	Status/Cause: HW interrupt 4 (PRENMI)

#define	C0_INTERRUPT_5 0x00002000
	Status/Cause: HW interrupt 5.

#define	C0_INTERRUPT_6 0x00004000
	Status/Cause: HW interrupt 6.

#define	C0_INTERRUPT_7 0x00008000
	Status/Cause: HW interrupt 7 (Timer)

#define	C0_INTERRUPT_RCP C0_INTERRUPT_2
	Status/Cause: HW interrupt 2 (RCP)

#define	C0_INTERRUPT_CART C0_INTERRUPT_3
	Status/Cause: HW interrupt 3 (CART)

#define	C0_INTERRUPT_PRENMI C0_INTERRUPT_4
	Status/Cause: HW interrupt 4 (PRENMI)

#define	C0_INTERRUPT_TIMER C0_INTERRUPT_7
	Status/Cause: HW interrupt 7 (Timer)

#define	C0_GET_CAUSE_CE(cr) (((cr) & C0_CAUSE_CE) >> 28)
	Get the CE value from the COP0 status register. More...

#define	C0_GET_CAUSE_EXC_CODE(sr) (((sr) & C0_CAUSE_EXC_CODE) >> 2)
	Get the exception code value from the COP0 status register value.

#define	C0_ENTRYLO_GLOBAL (1<<0)
	ENTRYLO: mapping is global (all ASIDs)

#define	C0_ENTRYLO_VALID (1<<1)
	ENTRYLO: mapping is active (not disabled)

#define	C0_ENTRYLO_DIRTY (1<<2)
	ENTRYLO: mapping is writable.

#define	C0_INDEX_PROBE_FAILED (1<<31)
	INDEX: set when a TLBP probe failed to find a match.

#define	C0_TLBWI() asm volatile("tlbwi; nop; nop; nop; nop")
	COP0 TLBWI opcode. More...

#define	C0_TLBWR() asm volatile("tlbwr; nop; nop; nop; nop")
	COP0 TLBWR opcode. More...

#define	C0_TLBR() asm volatile("tlbr; nop; nop; nop; nop")
	COP0 TLBR opcode. More...

#define	C0_TLBP() asm volatile("tlbp; nop; nop; nop; nop")
	COP0 TLBP opcode. More...

#define	C1_FLAG_INEXACT_OP 0x00000004
	Flag recording inexact operation.

#define	C1_FLAG_UNDERFLOW 0x00000008
	Flag recording underflow.

#define	C1_FLAG_OVERFLOW 0x00000010
	Flag recording overflow.

#define	C1_FLAG_DIV_BY_0 0x00000020
	Flag recording division by zero.

#define	C1_FLAG_INVALID_OP 0x00000040
	Flag recording invalid operation.

#define	C1_ENABLE_INEXACT_OP 0x00000080
	Enable inexact operation exception.

#define	C1_ENABLE_UNDERFLOW 0x00000100
	Enable underflow exception.

#define	C1_ENABLE_OVERFLOW 0x00000200
	Enable overflow exception.

#define	C1_ENABLE_DIV_BY_0 0x00000400
	Enable division by zero exception.

#define	C1_ENABLE_INVALID_OP 0x00000800
	Enable invalid operation exception.

#define	C1_ENABLE_MASK 0x00000F80
	Mask for all enable bits.

#define	C1_CAUSE_INEXACT_OP 0x00001000
	Triggered inexact operation exception.

#define	C1_CAUSE_UNDERFLOW 0x00002000
	Triggered underflow exception.

#define	C1_CAUSE_OVERFLOW 0x00004000
	Triggered overflow exception.

#define	C1_CAUSE_DIV_BY_0 0x00008000
	Triggered division by zero exception.

#define	C1_CAUSE_INVALID_OP 0x00010000
	Triggered invalid operation exception.

#define	C1_CAUSE_NOT_IMPLEMENTED 0x00020000
	Triggered not implemented exception.

#define	C1_CAUSE_MASK 0x0003F000
	Mask for all cause bits.

#define	C1_FCR31_FS (1<<24)
	Flush denormals to zero/min.

#define	C1_FCR31()
	Read the COP1 FCR31 register (floating-point control register 31) More...

#define	C1_WRITE_FCR31(x)
	Write to the COP1 FCR31 register. More...

#define	RCP_FREQUENCY (__bbplayer ? 96000000 : 62500000)
	Frequency of the RCP.

#define	CPU_FREQUENCY (__bbplayer ? 144000000 : 93750000)
	Frequency of the MIPS R4300 CPU.

#define	KSEG0_START_ADDR ((void*)0x80000000)
	void pointer to cached and non-mapped memory start address

#define	UncachedAddr(_addr) ((void *)(((unsigned long)(_addr))\|0x20000000))
	Return the uncached memory address for a given address. More...

#define	UncachedShortAddr(_addr) ((short *)(((unsigned long)(_addr))\|0x20000000))
	Return the uncached memory address for a given address. More...

#define	UncachedUShortAddr(_addr) ((unsigned short *)(((unsigned long)(_addr))\|0x20000000))
	Return the uncached memory address for a given address. More...

#define	UncachedLongAddr(_addr) ((long *)(((unsigned long)(_addr))\|0x20000000))
	Return the uncached memory address for a given address. More...

#define	UncachedULongAddr(_addr) ((unsigned long *)(((unsigned long)(_addr))\|0x20000000))
	Return the uncached memory address for a given address. More...

#define	CachedAddr(_addr) ((void *)(((unsigned long)(_addr))&~0x20000000))
	Return the cached memory address for a given address. More...

#define	PhysicalAddr(_addr)
	Return the physical memory address for a given address. More...

#define	HEAP_START_ADDR ((void*)__bss_end)
	Void pointer to the start of heap memory.

#define	MEMORY_BARRIER() asm volatile ("" : : : "memory")
	Memory barrier to ensure in-order execution. More...

#define	TICKS_READ() C0_COUNT()
	Returns the COP0 register $9 (count). More...

#define	TICKS_PER_SECOND (CPU_FREQUENCY/2)
	Number of updates to the count register per second. More...

#define	TICKS_DISTANCE(from, to) ((int32_t)((uint32_t)(to) - (uint32_t)(from)))
	The signed difference of time between "from" and "to". More...

#define	TICKS_SINCE(t0) TICKS_DISTANCE(t0, TICKS_READ())
	Return how much time has passed since the instant t0.

#define	TICKS_BEFORE(t1, t2) ({ TICKS_DISTANCE(t1, t2) > 0; })
	Returns true if "t1" is before "t2". More...

#define	TICKS_FROM_MS(val) ((uint32_t)((val) * (TICKS_PER_SECOND / 1000)))
	Returns equivalent count ticks for the given millis.

#define	data_cache_hit_invalidate(addr_, sz_)
	Force a data cache invalidate over a memory region. More...

Enumerations
enum	tv_type_t { TV_PAL = 0 , TV_NTSC = 1 , TV_MPAL = 2 }
	Type of TV video output. More...

Functions
bool	sys_bbplayer (void)
	Return true if we are running on a iQue player.

int	sys_get_boot_cic ()
	Return the boot CIC. More...

void	sys_set_boot_cic (int bc)
	Set the boot CIC. More...

void	data_cache_hit_writeback (volatile const void *addr, unsigned long length)
	Force a data cache writeback over a memory region. More...

void	__data_cache_hit_invalidate (volatile void *addr, unsigned long length)
	Underlying implementation of data_cache_hit_invalidate.

void	data_cache_hit_writeback_invalidate (volatile void *addr, unsigned long length)
	Force a data cache writeback invalidate over a memory region. More...

void	data_cache_index_writeback_invalidate (volatile void *addr, unsigned long length)
	Force a data cache index writeback invalidate over a memory region. More...

void	data_cache_writeback_invalidate_all (void)
	Force a data cache writeback invalidate over whole memory. More...

void	inst_cache_hit_writeback (volatile const void *addr, unsigned long length)
	Force an instruction cache writeback over a memory region. More...

void	inst_cache_hit_invalidate (volatile void *addr, unsigned long length)
	Force an instruction cache invalidate over a memory region. More...

void	inst_cache_index_invalidate (volatile void *addr, unsigned long length)
	Force an instruction cache index invalidate over a memory region. More...

void	inst_cache_invalidate_all (void)
	Force an instruction cache invalidate over whole memory. More...

void *	malloc_uncached (size_t size)
	Allocate a buffer that will be accessed as uncached memory. More...

void *	malloc_uncached_aligned (int align, size_t size)
	Allocate a buffer that will be accessed as uncached memory, specifying alignment. More...

void	free_uncached (void *buf)
	Free an uncached memory buffer. More...

int	get_memory_size ()
	Get amount of available memory. More...

bool	is_memory_expanded ()
	Is expansion pak in use. More...

tv_type_t	get_tv_type ()
	Is system NTSC/PAL/MPAL. More...

void	wait_ticks (unsigned long wait)
	Spin wait until the number of ticks have elapsed. More...

void	wait_ms (unsigned long wait_ms)
	Spin wait until the number of milliseconds have elapsed. More...

void	__init_cop1 ()
	Initialize COP1 with default settings that prevent undesirable exceptions.

volatile unsigned long	get_ticks (void)
	Read the number of ticks since system startup. More...

volatile unsigned long	get_ticks_ms (void)
	Read the number of millisecounds since system startup. More...

Variables
int	__bbplayer = 0
	Indicates whether we are running on a vanilla N64 or a iQue player.

int	__bootcic = 6102
	Boot CIC. More...

int	__bbplayer
	Indicates whether we are running on a vanilla N64 or a iQue player.

char	__libdragon_text_start []
	Symbol at the start of code (start of ROM contents after header)

char	__rom_end []
	Symbol at the end of code, data, and sdata (set by the linker)

char	__bss_end []
	Symbol at the end of code, data, sdata, and bss (set by the linker)

Detailed Description

N64 bootup and cache interfaces.

The N64 system interface provides a way for code to interact with the memory setup on the system. This includes cache operations to invalidate or flush regions and the ability to set the boot CIC. The newlib Interface Hooks use the knowledge of the boot CIC to properly determine if the expansion pak is present, giving 4 MiB of additional memory. Aside from this, the MIPS r4300 uses a manual cache management strategy, where SW that requires passing buffers to and from hardware components using DMA controllers needs to ensure that cache and RDRAM are in sync. A set of operations to invalidate and/or write back cache is provided for both instruction cache and data cache.

Macro Definition Documentation

◆ cache_op

#define cache_op	(	op,
		linesize
	)

Value:

    ({ \
    if (length) { \
        void *cur = (void*)((unsigned long)addr & ~(linesize-1)); \
        int count = (int)length + (addr-cur); \
        for (int i = 0; i < count; i += linesize) \
            asm ("\tcache %0,(%1)\n"::"i" (op), "r" (cur+i)); \
    } \
})

Helper macro to perform cache refresh operations.

Parameters

[in]	op	Operation to perform
[in]	linesize	Size of a cacheline in bytes

◆ C0_COUNT

#define C0_COUNT ( )

Value:

    ({ \
    uint32_t x; \
    asm volatile("mfc0 %0,$9":"=r"(x)); \
    x; \
})

Read the COP0 Count register (see also TICKS_READ).

◆ C0_WRITE_COUNT

#define C0_WRITE_COUNT ( x )

Value:

    ({ \
    asm volatile("mtc0 %0,$9"::"r"(x)); \
})

Write the COP0 Count register.

◆ C0_COMPARE

#define C0_COMPARE ( )

Value:

    ({ \
    uint32_t x; \
    asm volatile("mfc0 %0,$11":"=r"(x)); \
    x; \
})

Read the COP0 Compare register.

◆ C0_WRITE_COMPARE

#define C0_WRITE_COMPARE ( x )

Value:

    ({ \
    asm volatile("mtc0 %0,$11"::"r"(x)); \
})

Write the COP0 Compare register.

◆ C0_STATUS

#define C0_STATUS ( )

Value:

    ({ \
    uint32_t x; \
    asm volatile("mfc0 %0,$12":"=r"(x)); \
    x; \
})

Read the COP0 Status register.

◆ C0_WRITE_STATUS

#define C0_WRITE_STATUS ( x )

Value:

    ({ \
    asm volatile("mtc0 %0,$12"::"r"(x)); \
})

Write the COP0 Status register.

◆ C0_CAUSE

#define C0_CAUSE ( )

Value:

    ({ \
    uint32_t x; \
    asm volatile("mfc0 %0,$13" : "=r" (x) : ); \
    x; \
})

Returns the COP0 register $13 (Cause Register)

The coprocessor 0 (system control coprocessor - COP0) register $13 is a read write register keeping pending interrupts, exception code, coprocessor unit number referenced for a coprocessor unusable exception.

See also: C0_GET_CAUSE_EXC_CODE, C0_GET_CAUSE_CE and C0_CAUSE_BD

◆ C0_WRITE_CAUSE

#define C0_WRITE_CAUSE ( x )

Value:

    ({ \
    asm volatile("mtc0 %0,$13"::"r"(x)); \
})

Write the COP0 register $13 (Cause register)

Use this to update it for a custom exception handler.

◆ C0_BADVADDR

#define C0_BADVADDR ( )

Value:

    ({ \
    uint64_t x; \
    asm volatile("dmfc0 %0,$8" : "=r" (x) : ); \
    x; \
})

Returns the COP0 register $8 (BadVAddr)

The coprocessor 0 (system control coprocessor - COP0) register $8 is a read only register holding the last virtual address to be translated which became invalid, or a virtual address for which an addressing error occurred.

◆ C0_EPC

#define C0_EPC ( )

Value:

    ({ \
    uint32_t x; \
    asm volatile("mfc0 %0,$14" : "=r" (x) : ); \
    x; \
})

Read the COP0 register $14 (EPC)

The coprocessor 0 (system control coprocessor - COP0) register $14 is the return from exception program counter. For asynchronous exceptions it points to the place to continue execution whereas for synchronous (caused by code) exceptions, point to the instruction causing the fault condition, which needs correction in the exception handler. This macro is for reading its value.

◆ C0_INDEX

#define C0_INDEX ( )

Value:

    ({ \
    uint32_t x; \
    asm volatile("mfc0 %0,$0":"=r"(x)); \
    x; \
})

Read the COP0 INDEX register.

This register is used during TLB programming. It holds the index of the TLB entry being accessed (0-31).

◆ C0_WRITE_INDEX

#define C0_WRITE_INDEX ( x ) asm volatile("mtc0 %0,$0; nop; nop"::"r"(x))

Write the COP0 INDEX register.

This register is used during TLB programming. It holds the index of the TLB entry being accessed (0-31).

◆ C0_ENTRYHI

#define C0_ENTRYHI ( )

Value:

    ({ \
    uint32_t x; \
    asm volatile("mfc0 %0,$10":"=r"(x)); \
    x; \
})

Read the COP0 ENTRYHI register.

This register is used during TLB programming. It holds the configuration of the virtual memory entry for the TLB slot being accessed.

◆ C0_WRITE_ENTRYHI

#define C0_WRITE_ENTRYHI ( x ) asm volatile("mtc0 %0,$10; nop; nop"::"r"(x))

Write the COP0 ENTRYHI register.

This register is used during TLB programming.

◆ C0_ENTRYLO0

#define C0_ENTRYLO0 ( )

Value:

    ({ \
    uint32_t x; \
    asm volatile("mfc0 %0,$2":"=r"(x)); \
    x; \
})

Read the COP0 ENTRYLO0 register.

This register is used during TLB programming. It holds the configuration of the physical memory entry (even bank) for the TLB slot being accessed.

◆ C0_WRITE_ENTRYLO0

#define C0_WRITE_ENTRYLO0 ( x ) asm volatile("mtc0 %0,$2; nop; nop"::"r"(x))

Write the COP0 ENTRYLO0 register.

This register is used during TLB programming. It holds the configuration of the physical memory entry (even bank) for the TLB slot being accessed.

◆ C0_ENTRYLO1

#define C0_ENTRYLO1 ( )

Value:

    ({ \
    uint32_t x; \
    asm volatile("mfc0 %0,$3":"=r"(x)); \
    x; \
})

Read the COP0 ENTRYLO1 register.

This register is used during TLB programming. It holds the configuration of the physical memory entry (odd bank) for the TLB slot being accessed.

◆ C0_WRITE_ENTRYLO1

#define C0_WRITE_ENTRYLO1 ( x ) asm volatile("mtc0 %0,$3; nop; nop"::"r"(x))

Write the COP0 ENTRYLO1 register.

This register is used during TLB programming. It holds the configuration of the physical memory entry (even bank) for the TLB slot being accessed.

◆ C0_PAGEMASK

#define C0_PAGEMASK ( )

Value:

    ({ \
    uint32_t x; \
    asm volatile("mfc0 %0,$5":"=r"(x)); \
    x; \
})

Read the COP0 PAGEMASK register.

This register is used during TLB programming. It holds the bitmask that configures the page size of the TLB slot being accessed.

◆ C0_WRITE_PAGEMASK

#define C0_WRITE_PAGEMASK ( x ) asm volatile("mtc0 %0,$5; nop; nop"::"r"(x))

Write the COP0 PAGEMASK register.

This register is used during TLB programming. It holds the bitmask that configures the page size of the TLB slot being accessed.

◆ C0_WIRED

#define C0_WIRED ( )

Value:

    ({ \
    uint32_t x; \
    asm volatile("mfc0 %0,$6":"=r"(x)); \
    x; \
})

Read the COP0 WIRED register.

This register is used during TLB programming. It allows to partition TLB slots between fixed slots and random slots. The fixed slot pool is the range [0..WIRED[ and the random pool is the range [WIRED..32[

◆ C0_WATCHLO

#define C0_WATCHLO ( )

Value:

    ({ \
    uint32_t x; \
    asm volatile("mfc0 %0,$18":"=r"(x)); \
    x; \
})

Read the COP0 WATCHLO register.

This register is used during watchpoint programming. It allows to trigger an exception when a memory access occurs on a specific memory location.

◆ C0_WRITE_WATCHLO

#define C0_WRITE_WATCHLO ( x ) asm volatile("mtc0 %0,$18"::"r"(x))

Write the COP0 WATCHLO register.

This register is used during watchpoint programming. It allows to trigger an exception when a memory access occurs on a specific memory location.

◆ C0_WRITE_WIRED

#define C0_WRITE_WIRED ( x ) asm volatile("mtc0 %0,$6; nop; nop"::"r"(x))

Write the COP0 WIRED register.

This register is used during TLB programming. It allows to partition TLB slots between fixed slots and random slots. The fixed slot pool is the range [0..WIRED[ and the random pool is the range [WIRED..32[

◆ C0_GET_CAUSE_CE

#define C0_GET_CAUSE_CE ( cr ) (((cr) & C0_CAUSE_CE) >> 28)

Get the CE value from the COP0 status register.

Gets the Coprocessor unit number referenced by a coprocessor unusable exception from the given COP0 Status register value.

◆ C0_TLBWI

#define C0_TLBWI ( ) asm volatile("tlbwi; nop; nop; nop; nop")

COP0 TLBWI opcode.

This opcode is used during TLB programming. It writes the TLB slot referenced by INDEX with the contents of PAGEMASK, ENTRYHI, ENTRYLO0, ENTRYLO1.

◆ C0_TLBWR

#define C0_TLBWR ( ) asm volatile("tlbwr; nop; nop; nop; nop")

COP0 TLBWR opcode.

This opcode is used during TLB programming. It writes a random TLB slot with the contents of PAGEMASK, ENTRYHI, ENTRYLO0, ENTRYLO1. THe slot is selected in the random pool (slots in the range from WIRED to 31).

◆ C0_TLBR

#define C0_TLBR ( ) asm volatile("tlbr; nop; nop; nop; nop")

COP0 TLBR opcode.

This opcode is used during TLB programming. It reads the contents of the TLB slot referenced by INDEX into the registers PAGEMASK, ENTRYHI, ENTRYLO0 and ENTRYLO1.

◆ C0_TLBP

#define C0_TLBP ( ) asm volatile("tlbp; nop; nop; nop; nop")

COP0 TLBP opcode.

This opcode is used during TLB programming. It probes the current TLB slots using ENTRYHI (virtual address) to find a matching slot. If it finds, it loads its index into INDEX. Otherwise, it sets the C0_INDEX_PROBE_FAILED bit in INDEX.

◆ C1_FCR31

#define C1_FCR31 ( )

Value:

    ({ \
    uint32_t x; \
    asm volatile("cfc1 %0,$f31":"=r"(x)); \
    x; \
})

Read the COP1 FCR31 register (floating-point control register 31)

FCR31 is also known as the Control/Status register. It keeps control and status data for the FPU.

◆ C1_WRITE_FCR31

#define C1_WRITE_FCR31 ( x )

Value:

    ({ \
    asm volatile("ctc1 %0,$f31"::"r"(x)); \
})

Write to the COP1 FCR31 register.