Add basic CPU-related ideas.

4 files changed, 33 insertions, 0 deletions

diff --git a/cpu/interrupts/hardware/execution.txt b/cpu/interrupts/hardware/execution.txt
new file mode 100644
index 0000000..c3cc5f5
--- /dev/null
+++ b/cpu/interrupts/hardware/execution.txt
@@ -0,0 +1,10 @@
+When a hardware interrut occurs:
+	OPR gets set to the PR from the previous code running
+	OIP gets set to the IP from the previous code running
+	PR is set to all 1s
+
+The next hardware interrupt will not occur until after the current processing has been finished via `ireth`
+
+When returning via ireth:
+	PR is set to OPR
+	Execution jumps to OIP
diff --git a/cpu/interrupts/hardware/irqt.txt b/cpu/interrupts/hardware/irqt.txt
new file mode 100644
index 0000000..f1f5792
--- /dev/null
+++ b/cpu/interrupts/hardware/irqt.txt
@@ -0,0 +1,4 @@
+Each entry is n bits long, where n is the current mode in bits
+TODO: Specify a limit for them
+
+Each entry is a pointer to the code to be executed
diff --git a/cpu/interrupts/software/execution.txt b/cpu/interrupts/software/execution.txt
new file mode 100644
index 0000000..0cad31b
--- /dev/null
+++ b/cpu/interrupts/software/execution.txt
@@ -0,0 +1,8 @@
+When calling a software interrupt:
+	R0 gets overwritten with the current PR
+	R1 gets overwritten with a pointer of the same segment as IP, pointing to the next instruction
+	PR is set to all 1s
+
+When returning via iretp:
+	PR is set to R0
+	Execution jumps to R1
diff --git a/cpu/interrupts/software/idt.txt b/cpu/interrupts/software/idt.txt
new file mode 100644
index 0000000..04cafd9
--- /dev/null
+++ b/cpu/interrupts/software/idt.txt
@@ -0,0 +1,11 @@
+Each enty is n*2 bits long, where n is the current mode in bits
+TODO: Specify a limit for them
+
+It uses the following format:
+	(higher address)
+	+--------------------------------+
+	| Pointer to executable code run |
+	+--------------------------------+
+	| Privileges required for usage  |
+	+--------------------------------+
+	(lower address)