From 7ae51a4849e498925c20dfad14a456bb42cdf6e8 Mon Sep 17 00:00:00 2001
From: Santiago Lo Coco <slococo@itba.edu.ar>
Date: Wed, 27 Oct 2021 23:44:01 -0300
Subject: [PATCH] Save x87 state on context switch

---
 Kernel/asm/interrupts.asm | 56 ++++++++++++++++++++++++---------------
 Kernel/utils/scheduler.c  | 33 ++++++++++++++++++-----
 2 files changed, 60 insertions(+), 29 deletions(-)

diff --git a/Kernel/asm/interrupts.asm b/Kernel/asm/interrupts.asm
index 06760ff..28c1f21 100755
--- a/Kernel/asm/interrupts.asm
+++ b/Kernel/asm/interrupts.asm
@@ -171,12 +171,15 @@ picSlaveMask:
 _irq00Handler:
 	pushState
 
-	; mov rsi, rsp
-	; and rsp, -16
-	; sub rsp, 108
-	; fsave [rsp]
-	; push rsi
-	
+	mov rsi, rsp
+	and rsp, -16
+	sub rsp, 108
+	fsave [rsp]
+	and rsp, -16
+	sub rsp, 512
+	fxsave [rsp]
+	push rsi
+
 	; push rax
 	; call getFPUaddress
 	; fsave [rax]
@@ -207,12 +210,15 @@ _irq00Handler:
 	; fxrstor [rax]
 	; pop rax
 	
-	; mov rax, rsp
-	; pop rsp
-	; and rsp, -16
-	; sub rsp, 108
-	; frstor [rsp]
-	; mov rsp, rax
+	pop rsp
+	mov rax, rsp
+	and rsp, -16
+	sub rsp, 108
+	frstor [rsp]
+	and rsp, -16
+	sub rsp, 512
+	fxrstor [rsp]
+	mov rsp, rax
 
 	popState
 	iretq
@@ -300,20 +306,26 @@ _initialize_stack_frame:
 
     pushState
 
-	; mov rsi, rsp
-	; and rsp, -16
-	; sub rsp, 108
-	; fsave [rsp]
-	; push rsi
+	mov rsi, rsp
+	and rsp, -16
+	sub rsp, 108
+	fsave [rsp]
+	and rsp, -16
+	sub rsp, 512
+	fxsave [rsp]
+	push rsi
+	mov rax, rsp
 
 	; fsave [bytesForFPU]
-	; push rax
-	; mov dword [auxi], 1
-	; call getFPUaddress
-	; call getSSEaddress
-	; pop rax
 	; fxsave [bytesForSSEAligned]
 
+	; push rax
+	; call getFPUaddress
+	; fsave [rax]
+	; call getSSEaddress
+	; fxsave [rax]
+	; pop rax
+
 	; fsave [r8]
 	; fxsave [r9]
 
diff --git a/Kernel/utils/scheduler.c b/Kernel/utils/scheduler.c
index 2d4eb5c..b453ad4 100644
--- a/Kernel/utils/scheduler.c
+++ b/Kernel/utils/scheduler.c
@@ -2,10 +2,23 @@
 #define IDLE_PID 1
 
 // void _initialize_stack_frame(void *, void *, int, char**, void **, void **);
-void _initialize_stack_frame(void *, void *, int, char**);
+// void _initialize_stack_frame(void *, void *, int, char**, void *, void *);
+uint64_t * _initialize_stack_frame(void *, void *, int, char**);
 
 enum states {READY = 0, BLOCKED};
 
+// typedef long Align;
+
+// union header {
+//   struct {
+//     void * fpuBytes;
+//     void * sseBytes;
+//   } s;
+//   Align x;
+// };
+
+// typedef union header Header;
+
 typedef struct processCDT {
     struct processCDT * next;
     char * name;
@@ -18,12 +31,12 @@ typedef struct processCDT {
     char foreground;
     enum states state;
     int * fd;
+    // Header * bytes;
+    // Header * sse;
     // void * sseBytes;
     // void * fpuBytes;
 } processCDT;
 
-// typedef long Align;
-
 // typedef union processCDT {
 //  struct {
 //     struct p * next;
@@ -104,7 +117,7 @@ void enqueueProcess(void (*fn) (int, char **), char foreground, int argc, char *
     processADT process = pvPortMalloc(sizeof(processCDT));
     uint64_t * auxi = pvPortMalloc(STACK_SIZE);
     uint64_t * rbp = STACK_SIZE + auxi;
-    uint64_t * rsp = rbp - 20; //22
+    uint64_t * rsp = rbp - 20; // 20 //22
     
     char priority = (foreground == 1) ? DEF_PRIORITY : MAX_PRIORITY/2;
 
@@ -127,11 +140,15 @@ void enqueueProcess(void (*fn) (int, char **), char foreground, int argc, char *
     process->state = READY;
     process->fd = fd;
     process->next = NULL;
+    // process->bytes->s.fpuBytes = pvPortMalloc(108);
+    // process->bytes->s.sseBytes = pvPortMalloc(512);
     // process->sseBytes = pvPortMalloc(64);
     // process->fpuBytes = pvPortMalloc(14);
 
     // _initialize_stack_frame(fn, rbp, argc, argv, &(process->fpuBytes), &(process->sseBytes));
-    _initialize_stack_frame(fn, rbp, argc, argv);
+    // _initialize_stack_frame(fn, rbp, argc, argv, &(process->bytes->s.sseBytes), &(process->bytes->s.fpuBytes));
+    // _initialize_stack_frame(fn, rbp, argc, argv, process->bytes->s.sseBytes, process->bytes->s.fpuBytes);
+    process->rsp = _initialize_stack_frame(fn, rbp, argc, argv);
 
     if (firstReady == NULL)
         firstReady = process;
@@ -143,11 +160,13 @@ void enqueueProcess(void (*fn) (int, char **), char foreground, int argc, char *
 }
 
 // void * getSSEaddress() {
-//     return currentProcess->sseBytes;
+// //     return currentProcess->sseBytes;
+//     return currentProcess->bytes->s.sseBytes;
 // }
 
 // void * getFPUaddress() {
-//     return currentProcess->fpuBytes;
+//     // return currentProcess->fpuBytes;
+//     return currentProcess->bytes->s.fpuBytes;
 // }
 
 void newProcess(processADT process, char * name, char priority, char foreground, uint64_t rsp, uint64_t rbp) {