C++ Crashkurs
Implements an abstraction for CPU internals. More...
Namespaces | |
| Interrupt | |
| Exception and Interrupt control. | |
Classes | |
| class | CR |
| Access to the Control Register. More... | |
| class | MSR |
| Access to the Model-Specific Register (MSR) More... | |
Enumerations | |
| enum | CR0 : uintptr_t { CR0_PE = 1U << 0, CR0_MP = 1U << 1, CR0_EM = 1U << 2, CR0_TS = 1U << 3, CR0_ET = 1U << 4, CR0_NE = 1U << 5, CR0_WP = 1U << 16, CR0_AM = 1U << 18, CR0_NW = 1U << 29, CR0_CD = 1U << 30, CR0_PG = 1U << 31 } |
| Control Register 0. More... | |
| enum | CR4 : uintptr_t { CR4_VME = 1U << 0, CR4_PVI = 1U << 1, CR4_TSD = 1U << 2, CR4_DE = 1U << 3, CR4_PSE = 1U << 4, CR4_PAE = 1U << 5, CR4_MCE = 1U << 6, CR4_PGE = 1U << 7, CR4_PCE = 1U << 8, CR4_OSFXSR = 1U << 9, CR4_OSXMMEXCPT = 1U << 10, CR4_UMIP = 1U << 11, CR4_VMXE = 1U << 13, CR4_SMXE = 1U << 14, CR4_FSGSBASE = 1U << 16, CR4_PCIDE = 1U << 17, CR4_OSXSAVE = 1U << 18, CR4_SMEP = 1U << 20, CR4_SMAP = 1U << 21, CR4_PKE = 1U << 22 } |
| Control Register 4. More... | |
| enum | MSRs : uint32_t { MSR_PLATFORM_INFO = 0xceU, MSR_TSC_DEADLINE = 0x6e0U, MSR_EFER = 0xC0000080U, MSR_STAR = 0xC0000081U, MSR_LSTAR = 0xC0000082U, MSR_SFMASK = 0xC0000084U, MSR_FS_BASE = 0xC0000100U, MSR_GS_BASE = 0xC0000101U, MSR_SHADOW_GS_BASE = 0xC0000102U } |
| Model-Specific Register Identifiers. More... | |
| enum | MSR_EFER : uintptr_t { MSR_EFER_SCE = 1U << 0, MSR_EFER_LME = 1U << 8, MSR_EFER_LMA = 1U << 10, MSR_EFER_NXE = 1U << 11, MSR_EFER_SVME = 1U << 12, MSR_EFER_LMSLE = 1U << 13, MSR_EFER_FFXSR = 1U << 14, MSR_EFER_TCE = 1U << 15 } |
Functions | |
| void | init () |
| Initialize this CPU core. More... | |
| void | exit () |
| Deinitialize this CPU core. More... | |
| unsigned | getID () |
| Get the ID of the current CPU core using LAPIC::getID() with an internal lookup table. More... | |
| unsigned | count () |
| Get number of available CPU cores. More... | |
| unsigned | countOnline () |
| Get number of successfully started (and currently active) CPU cores. More... | |
| bool | isOnline (uint8_t core_id) |
| Check if CPU core is currently active. More... | |
| void | pause () |
| Gives the core a hint that it is executing a spinloop and should sleep "shortly". More... | |
| void | idle () |
| Halt the CPU core until the next interrupt. More... | |
| void | die () |
| Permanently halts the core. More... | |
Constants | |
| const unsigned | MAX = 8 |
| Maximum number of supported CPUs. | |
Detailed Description
Implements an abstraction for CPU internals.
These internals include functions to allow or deny interrupts, access control registers as well as model specific registers.
Enumeration Type Documentation
| enum Core::CR0 : uintptr_t |
Control Register 0.
- See also
- ISDMv3, 2.5 Control Registers
| enum Core::CR4 : uintptr_t |
Control Register 4.
- See also
- ISDMv3, 2.5 Control Registers
| enum Core::MSRs : uint32_t |
Model-Specific Register Identifiers.
Selection of useful identifiers.
- See also
- ISDMv4
| Enumerator | |
|---|---|
| MSR_PLATFORM_INFO | Platform information including bus frequency (Intel) |
| MSR_TSC_DEADLINE | Register for LAPIC::Timer Deadline mode. |
| MSR_EFER | Extended Feature Enable Register,.
|
| MSR_STAR | eip (protected mode), ring 0 and 3 segment bases |
| MSR_LSTAR | rip (long mode) |
| MSR_SFMASK | lower 32 bit: flag mask, if bit is set corresponding rflag is cleared through syscall |
| MSR_GS_BASE | Current GS base pointer. |
| MSR_SHADOW_GS_BASE | Usually called |
| enum Core::MSR_EFER : uintptr_t |
Function Documentation
| void Core::init | ( | ) |
Initialize this CPU core.
Mark this core as online and setup the cores LAPIC by assigning it a unique logical APIC ID
- Note
- Should only be called from kernel_init() during startup.
| void Core::exit | ( | ) |
Deinitialize this CPU core.
Mark this Core as offline
- Note
- Should only be called from kernel_init() after returning from
main()ormain_ap().
| unsigned Core::getID | ( | ) |
Get the ID of the current CPU core using LAPIC::getID() with an internal lookup table.
- Returns
- ID of current Core (a number between 0 and Core::MAX)
| unsigned Core::count | ( | ) |
Get number of available CPU cores.
- Returns
- total number of cores
| unsigned Core::countOnline | ( | ) |
Get number of successfully started (and currently active) CPU cores.
- Returns
- total number of online cores
| bool Core::isOnline | ( | uint8_t | core_id | ) |
Check if CPU core is currently active.
- Parameters
-
core_id ID of the CPU core
- Returns
trueif successfully started and is currently active
|
inline |
Gives the core a hint that it is executing a spinloop and should sleep "shortly".
Improves the over-all performance when executing a spinloop by waiting a short moment reduce the load on the memory.
|
inline |
Halt the CPU core until the next interrupt.
Halts the current CPU core such that it will wake up on the next interrupt. Internally, this function first enables the interrupts via sti and then halts the core using hlt. Halted cores can only be woken by interrupts. The effect of sti is delayed by one instruction, making the sequence sti hlt atomic (if interrupts were disabled previously).
|
inline |
Permanently halts the core.
Permanently halts the current CPU core. Internally, this function first disables the interrupts via cli and then halts the CPU core using hlt. As halted CPU cores can only be woken by interrupts, it is guaranteed that this core will be halted until the next reboot. The execution of die never returns. On multicore systems, only the executing CPU core will be halted permanently, other cores will continue execution.