From f3bf60db75b16d137437bc2296aaf771d94958d3 Mon Sep 17 00:00:00 2001 From: Elyan Date: Sun, 20 Oct 2024 18:23:00 +0200 Subject: [PATCH] Fix typo and reformulate phrases --- src/execution-engine-spec/glossary.adoc | 2 +- src/execution-engine-spec/instructions.adoc | 11 ++++++++++- src/execution-engine-spec/intro.adoc | 17 ++++++++++++----- src/execution-engine-spec/registers.adoc | 2 +- 4 files changed, 24 insertions(+), 8 deletions(-) diff --git a/src/execution-engine-spec/glossary.adoc b/src/execution-engine-spec/glossary.adoc index 5785630..3061b42 100644 --- a/src/execution-engine-spec/glossary.adoc +++ b/src/execution-engine-spec/glossary.adoc @@ -4,7 +4,7 @@ [glossary] [horizontal] Processing Complex:: - Composed of a _Processing Unit_, memory modules and subsystems that are not located inside of the _Processing Unit_ (e.g. Channel I/O Subsytem, Hardware Management Subsystem). + Composed of a _Processing Unit_, memory modules and subsystems that are not located inside of the _Processing Unit_ (e.g. Channel I/O Subsystem, Hardware Management Subsystem). The name applies both to the hardware enclosure and the hardware inside said enclosure. Processing Unit:: diff --git a/src/execution-engine-spec/instructions.adoc b/src/execution-engine-spec/instructions.adoc index fa1e1f7..dba7b5f 100644 --- a/src/execution-engine-spec/instructions.adoc +++ b/src/execution-engine-spec/instructions.adoc @@ -7,7 +7,7 @@ For instruction encoding formats that contain an immediate value, not all immedi include::images/instruction-formats.adoc[] -.Bit ranges legend +.Bits ranges legend opcode:: The operation to carry on. rd:: @@ -30,3 +30,12 @@ cmd:: === Instruction list #TODO: List instructions# +* memory load/store instructions +* register move instructions +* arithmetic instructions +* bitwise operations instructions (w/ bit shifts) +* comparison instructions +* jump instructions +* system mode instructions (svc, uret, sret, ...) +* subsystems instructions (ssr & ssw) + diff --git a/src/execution-engine-spec/intro.adoc b/src/execution-engine-spec/intro.adoc index bba388d..8ccbdb6 100644 --- a/src/execution-engine-spec/intro.adoc +++ b/src/execution-engine-spec/intro.adoc @@ -7,14 +7,14 @@ The {central-arch-name} uses byte-addressable memory. While an _Execution engine_ handles data 32-bits wide, memory addresses are only 24-bits wide. An _Execution Engine_ can thus address up to 16MB of main memory. -NOTE: We use the terms "`memory`" and "`main memory`" interchangably. Main memory refers to the RAM while we use the term "`secondary memory`" to refer to HDD or SSD storage. +NOTE: We use the terms "`memory`" and "`main memory`" interchangeably. Main memory refers to the RAM while we use the term "`secondary memory`" to refer to HDD or SSD storage. At the hardware level, memory accesses are done on a memory-word boundary. A memory-word is 32-bits wide and memory accesses should be done at a 32-bits alignment to avoid wasting cycles doing double the amount of memory operations. NOTE: The term "`memory accesses`" encompasses both read and write operations. -Data is encoded in memory with the little endian scheme. +Data is encoded in memory in little endian. For a given value, the least significant byte (LSB) is stored in the lowest address and the most significant byte (MSB) in the highest. === System Modes and Privilege Levels @@ -48,7 +48,7 @@ Supervisor-mode:: Software executing in this mode provides context switching, I/O, process management and inter-process communications. Fault-mode:: - Code executes in this mode when a double fault occurs, i.e. when an exception is generated in system-mode code. + Code executes in this mode when a double fault occurs, i.e. when an exception is generated in supervisor-mode code. Code executing under this mode can be used to log/report double faults and then reset/halt the system. Debug exceptions generated in supervisor-mode code are also handled in this mode, in which case control is passed back to supervisor-mode after handling. @@ -62,7 +62,7 @@ Exceptions thus always suspend user code for the duration of their handling. Exceptions can be of two types: *synchronous* and *asynchronous*. ==== Synchronous Exceptions -Synchronous exceptions are generated from events originating from inside of the _Execution engine_. +Synchronous exceptions are generated from events originating from inside of the _Execution Engine_. They are a conditional or unconditional response to the execution of an instruction. SVC:: @@ -84,11 +84,18 @@ Debug:: * Fetching an instruction located at an address matching a configured _Hardware Breakpoint_, * Accessing a memory address matching a configured _Hardware Watchpoint_ +SvcDebug:: + This exception is the same as the *Debug* exception, except it is generated when debug events are encountered while in supervisor-mode. + +UnknownInstr:: + This exception is generated when an unknown instruction failed to be executed. + It is important not to ignore this exception as it can be the symptom of a memory corruption bug. + ==== Asynchronous Exceptions Asynchronous exceptions are generated from events originating from outside of the _Execution engine_. These exceptions enable the system to react to its environment. -HardMgmt:: +HdwrMgmt:: This exception is generated when the _Hardware Management Console_ communicates with the _Processing Unit_ and that the _Processing Unit_ relays the event to the _Execution Engine_. Data can be passed alongside the exception and would be stored in main memory by the _Processing Unit_ communications controller. diff --git a/src/execution-engine-spec/registers.adoc b/src/execution-engine-spec/registers.adoc index c84c2e8..f78c6d0 100644 --- a/src/execution-engine-spec/registers.adoc +++ b/src/execution-engine-spec/registers.adoc @@ -1,7 +1,7 @@ === Registers ==== General Purpose Registers General purpose registers (GPRs) are used to perform calculations and store intermediate values. -There are 8 GPRs in an Execution Engine. These registers are named *_r0_* through *_r7_*. +There are 8 GPRs in an _Execution Engine_. These registers are named *_r0_* through *_r7_*. ==== Special Purpose Registers