diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/CPU-EMULATION.TXT | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/docs/CPU-EMULATION.TXT b/docs/CPU-EMULATION.TXT index 303d6c0..95f32b1 100644 --- a/docs/CPU-EMULATION.TXT +++ b/docs/CPU-EMULATION.TXT @@ -5,7 +5,7 @@ Translating ARM to x86 machine code: ------------------------------------ QEMU starts by isolating code "fragments" from the emulated machine code. -Each "fragment" corresponds to a seris of ARM instructions ending with a +Each "fragment" corresponds to a series of ARM instructions ending with a branch (e.g. jumps, conditional branches, returns). Each fragment is translated into a "translated block" (a.k.a. TB) of host @@ -28,7 +28,7 @@ again. CPU state is kept in a single global structure which the generated code can access directly (with direct memory addressing). -the file target-arm/translate.c is in charge of translating the ARM or +The file target-arm/translate.c is in charge of translating the ARM or Thumb instructions starting at the current instruction pointer position into a TB. This is done by decomposing each instruction into a series of micro-operations supported by the TCG code generator. @@ -62,13 +62,13 @@ translated from user-level code. This means that a memory load in the kernel will not be translated into the same instructions than the same load in user space. -Each TLB is also implemented as a global per-CPU hash-table. -The user-level TLB is flushed on each process context switch. +Each TLB is also implemented as a global per-emulated-CPU hash-table. +The user-level TLB is flushed on each process context switch. When initializing the MMU emulation, one can define several zones of the address space, with different access rights / type. This is how memory-mapped -i/o is implemented: the virtual->physical conversion helper function detects -that you're trying to read/write from an i/o memory region, and will then call +I/O is implemented: the virtual->physical conversion helper function detects +that you're trying to read/write from an I/O memory region, and will then call a callback function associated to it. @@ -76,8 +76,8 @@ Hardware Emulation: ------------------- Most hardware emulation code initializes by registering its own region of -i/o memory, as well as providing read/write callbacks for it. Then actions -will be based on which offset of the i/o memory is read from/written to and +I/O memory, as well as providing read/write callbacks for it. Then actions +will be based on which offset of the I/O memory is read from/written to and eventually with which value. You can have a look at hw/goldfish_tty.c that implements an emulated serial |