From e662d52a7317c23caf1d14addad746e9a7522f9b Mon Sep 17 00:00:00 2001
From: Matheus <matheusuky@gmail.com>
Date: Wed, 5 Jul 2023 19:48:32 -0300
Subject: [PATCH] Kernel: due to performance and real hardware testing reasons,
 put syscall logging and e9 behind compile time options

---
 kernel-src/Makefile                 | 3 ++-
 kernel-src/arch/x86-64/e9.c         | 4 ++++
 kernel-src/arch/x86-64/syscalllog.c | 8 ++++++++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/kernel-src/Makefile b/kernel-src/Makefile
index 4335ff4b..c96dd74e 100644
--- a/kernel-src/Makefile
+++ b/kernel-src/Makefile
@@ -10,7 +10,8 @@ LDFLAGS=-ffreestanding -nostdlib -lgcc -Wl,-T,"$(ARCHDIR)/kernel.ld" -g
 PRINTFOPTS=-DPRINTF_DISABLE_SUPPORT_FLOAT
 # flanterm includes break if the headers are moved into the include dir in the tree
 FLANTERMINCDIR=$(shell pwd)/flanterm
-CFLAGS=-g -ffreestanding -mcmodel=kernel -O2 -mno-red-zone -mgeneral-regs-only -mno-mmx -mno-sse -mno-sse2 -nostdlib -Wall -I "${INCDIR}" -I "$(ARCHINCDIR)" -I "$(FLANTERMINCDIR)" $(PRINTFOPTS)
+KERNELCONFIG=#-DX86_64_ENABLE_E9 -DSYSCALL_LOGGING
+CFLAGS=-g -ffreestanding -mcmodel=kernel -O2 -mno-red-zone -mgeneral-regs-only -mno-mmx -mno-sse -mno-sse2 -nostdlib -Wall -I "${INCDIR}" -I "$(ARCHINCDIR)" -I "$(FLANTERMINCDIR)" $(PRINTFOPTS) $(KERNELCONFIG)
 ASFLAGS=-felf64
 
 astral:	$(OBJS)
diff --git a/kernel-src/arch/x86-64/e9.c b/kernel-src/arch/x86-64/e9.c
index cf277e71..8c633eab 100644
--- a/kernel-src/arch/x86-64/e9.c
+++ b/kernel-src/arch/x86-64/e9.c
@@ -3,11 +3,15 @@
 // TODO compile time options for disabling output to port e9h
 
 void arch_e9_putc(char c) {
+#ifdef X86_64_ENABLE_E9
 	outb(0xe9, c);
+#endif
 }
 
 void arch_e9_puts(char *c) {
+#ifdef X86_64_ENABLE_E9
 	while (*c) {
 		outb(0xe9, *c++);
 	}
+#endif
 }
diff --git a/kernel-src/arch/x86-64/syscalllog.c b/kernel-src/arch/x86-64/syscalllog.c
index b12b1ab0..42fbff1f 100644
--- a/kernel-src/arch/x86-64/syscalllog.c
+++ b/kernel-src/arch/x86-64/syscalllog.c
@@ -2,6 +2,8 @@
 #include <arch/e9.h>
 #include <arch/cpu.h>
 
+#ifdef SYSCALL_LOGGING
+
 #define SYSCALL_COUNT 25
 #define LOGSTR(x) arch_e9_puts(x)
 
@@ -63,7 +65,10 @@ static char *args[] = {
 	"dirfd %d pathname %d flags %d" // unlinkat
 };
 
+#endif
+
 __attribute__((no_caller_saved_registers)) void arch_syscall_log(int syscall, uint64_t a1, uint64_t a2, uint64_t a3, uint64_t a4, uint64_t a5, uint64_t a6) {
+#ifdef SYSCALL_LOGGING
 	char argbuff[768];
 	char printbuff[1024];
 
@@ -74,9 +79,11 @@ __attribute__((no_caller_saved_registers)) void arch_syscall_log(int syscall, ui
 	snprintf(printbuff, 1024, "\e[92msyscall: pid %d tid %d: %s: %s\n\e[0m", proc->pid, thread->tid, syscall < SYSCALL_COUNT ? name[syscall] : "invalid syscall", argbuff);
 
 	LOGSTR(printbuff);
+#endif
 }
 
 __attribute__((no_caller_saved_registers)) void arch_syscall_log_return(uint64_t ret, uint64_t errno) {
+#ifdef SYSCALL_LOGGING
 	char printbuff[1024];
 
 	thread_t *thread = _cpu()->thread;
@@ -84,4 +91,5 @@ __attribute__((no_caller_saved_registers)) void arch_syscall_log_return(uint64_t
 
 	snprintf(printbuff, 1024, "\e[94msyscall return: pid %d tid %d: %lu %lu\n\e[0m", proc->pid, thread->tid, ret, errno);
 	LOGSTR(printbuff);
+#endif
 }