From c9d401f488b404bf0f4c11e1402987cb49195660 Mon Sep 17 00:00:00 2001
From: Matheus <matheusuky@gmail.com>
Date: Sun, 2 Nov 2025 21:30:24 -0300
Subject: [PATCH] syscalls: sysinfo

---
 kernel-src/arch/x86-64/syscall.asm  |  4 ++-
 kernel-src/arch/x86-64/syscalllog.c |  8 +++--
 kernel-src/include/kernel/pmm.h     |  1 +
 kernel-src/include/kernel/proc.h    |  1 +
 kernel-src/mm/pmm.c                 |  5 +++
 kernel-src/sys/proc.c               | 10 ++++++
 kernel-src/sys/syscalls/sysinfo.c   | 52 +++++++++++++++++++++++++++++
 7 files changed, 77 insertions(+), 4 deletions(-)
 create mode 100644 kernel-src/sys/syscalls/sysinfo.c

diff --git a/kernel-src/arch/x86-64/syscall.asm b/kernel-src/arch/x86-64/syscall.asm
index ff7c651b..316a3cb3 100644
--- a/kernel-src/arch/x86-64/syscall.asm
+++ b/kernel-src/arch/x86-64/syscall.asm
@@ -95,6 +95,7 @@ extern syscall_shutdown
 extern syscall_nice
 extern syscall_flock
 extern syscall_getcpu
+extern syscall_sysinfo
 syscalltab:
 dq syscall_print
 dq syscall_mmap
@@ -192,7 +193,8 @@ dq syscall_shutdown
 dq syscall_nice
 dq syscall_flock
 dq syscall_getcpu
-syscallcount equ 96
+dq syscall_sysinfo
+syscallcount equ 97
 section .text
 global arch_syscall_entry
 ; on entry:
diff --git a/kernel-src/arch/x86-64/syscalllog.c b/kernel-src/arch/x86-64/syscalllog.c
index 453e95c5..34ad4b1b 100644
--- a/kernel-src/arch/x86-64/syscalllog.c
+++ b/kernel-src/arch/x86-64/syscalllog.c
@@ -5,7 +5,7 @@
 
 #ifdef SYSCALL_LOGGING
 
-#define SYSCALL_COUNT 96
+#define SYSCALL_COUNT 97
 #define LOGSTR(x) arch_e9_puts(x)
 
 static char *name[] = {
@@ -104,7 +104,8 @@ static char *name[] = {
 	"shutdown",
 	"nice",
 	"flock",
-	"getcpu"
+	"getcpu",
+	"sysinfo"
 };
 
 static char *args[] = {
@@ -203,7 +204,8 @@ static char *args[] = {
 	"how %d", // shutdown
 	"off %d", // nice
 	"fd %d op %d", // flock
-	"N/A" // getcpu
+	"N/A", // getcpu
+	"ptr %p", // sysinfo
 };
 
 #endif
diff --git a/kernel-src/include/kernel/pmm.h b/kernel-src/include/kernel/pmm.h
index 97ed11c7..fc5b9f6b 100644
--- a/kernel-src/include/kernel/pmm.h
+++ b/kernel-src/include/kernel/pmm.h
@@ -46,6 +46,7 @@ void pmm_makefree(void *address, size_t count);
 void *pmm_alloc(size_t size, int section);
 void pmm_free(void *addr, size_t size);
 void pmm_init();
+void pmm_getinfo(size_t *total_pages, size_t *free_pages);
 
 extern uintptr_t hhdmbase;
 
diff --git a/kernel-src/include/kernel/proc.h b/kernel-src/include/kernel/proc.h
index ac487fc7..bb34e23b 100644
--- a/kernel-src/include/kernel/proc.h
+++ b/kernel-src/include/kernel/proc.h
@@ -112,5 +112,6 @@ pid_t proc_allocate_pid(void);
 void proc_init(void);
 void proc_exit(void);
 void proc_run_init();
+size_t proc_get_count(void);
 
 #endif
diff --git a/kernel-src/mm/pmm.c b/kernel-src/mm/pmm.c
index 9d6ac48b..45fa9c64 100644
--- a/kernel-src/mm/pmm.c
+++ b/kernel-src/mm/pmm.c
@@ -323,3 +323,8 @@ void pmm_free(void *addr, size_t size) {
 	for (int i = 0; i < size; ++i)
 		pmm_release((void *)((uintptr_t)addr + PAGE_SIZE * i));
 }
+
+void pmm_getinfo(size_t *total_pages, size_t *free_pages) {
+	*total_pages = pagecount;
+	*free_pages = freepagecount;
+}
diff --git a/kernel-src/sys/proc.c b/kernel-src/sys/proc.c
index e28959c1..9973d907 100644
--- a/kernel-src/sys/proc.c
+++ b/kernel-src/sys/proc.c
@@ -23,6 +23,16 @@ pid_t proc_allocate_pid(void) {
 	return __atomic_fetch_add(&currpid, 1, __ATOMIC_SEQ_CST);
 }
 
+size_t proc_get_count(void) {
+	MUTEX_ACQUIRE(&proc_pid_table_mutex);
+
+	size_t count = pid_table.entrycount;
+
+	MUTEX_RELEASE(&proc_pid_table_mutex);
+
+	return count;
+}
+
 proc_t *proc_get_from_pid(int pid) {
 	MUTEX_ACQUIRE(&proc_pid_table_mutex);
 	void *_proc = NULL;
diff --git a/kernel-src/sys/syscalls/sysinfo.c b/kernel-src/sys/syscalls/sysinfo.c
new file mode 100644
index 00000000..e1957f10
--- /dev/null
+++ b/kernel-src/sys/syscalls/sysinfo.c
@@ -0,0 +1,52 @@
+#include <kernel/syscalls.h>
+#include <arch/cpu.h>
+#include <kernel/pmm.h>
+#include <kernel/vmmcache.h>
+#include <kernel/proc.h>
+
+typedef struct {
+	long uptime;
+	unsigned long loads[3];
+	unsigned long totalram;
+	unsigned long freeram;
+	unsigned long sharedram;
+	unsigned long bufferram;
+	unsigned long totalswap;
+	unsigned long freeswap;
+	unsigned short procs;
+	unsigned long totalhigh;
+	unsigned long freehigh;
+	unsigned int mem_unit;
+	char _f[20 - 2 * sizeof(long) - sizeof(int)];
+} sysinfo_t;
+
+syscallret_t syscall_sysinfo(context_t *, sysinfo_t *usysinfo) {
+	syscallret_t ret = {
+		.ret = -1
+	};
+
+	size_t total_pages, free_pages;
+	pmm_getinfo(&total_pages, &free_pages);
+
+	sysinfo_t sysinfo = {
+		.uptime = timekeeper_timefromboot().s,
+		.totalram = total_pages,
+		.freeram = free_pages,
+		.sharedram = 0,
+		.bufferram = vmmcache_cachedpages,
+		.totalswap = 0,
+		.freeswap = 0,
+		.procs = proc_get_count(),
+		.totalhigh = 0,
+		.freehigh = 0,
+		.mem_unit = PAGE_SIZE
+	};
+
+	memset(sysinfo.loads, 0, sizeof(sysinfo.loads));
+	memset(sysinfo._f, 0, sizeof(sysinfo._f));
+
+	ret.errno = usercopy_touser(usysinfo, &sysinfo, sizeof(sysinfo));
+	ret.ret = ret.errno ? -1 : 0;
+
+	return ret;
+}