From e837f3a4fa9a11350cca0ce8e147787c3b4f6fdb Mon Sep 17 00:00:00 2001
From: "yu.dongliang" <18588496441@163.com>
Date: Wed, 28 Aug 2024 16:56:16 +0800
Subject: [PATCH] support argc & argv in main() for x64, support fopen(),
 fclose(), ...

---
 examples/fopen.c     |  26 ++++++++++++++++++++++++++
 examples/main_argv.c |  11 +++++++++++
 lib/_start.o         | Bin 840 -> 864 bytes
 lib/_start.s         |  13 ++++++++++++-
 4 files changed, 49 insertions(+), 1 deletion(-)
 create mode 100644 examples/fopen.c
 create mode 100644 examples/main_argv.c

diff --git a/examples/fopen.c b/examples/fopen.c
new file mode 100644
index 0000000..62be9a5
--- /dev/null
+++ b/examples/fopen.c
@@ -0,0 +1,26 @@
+/*#include<stdio.h>
+#include<stdint.h>
+*/
+void*   fopen(const char* path, const char* mode);
+int     fclose(void* fp);
+int     fscanf(void* fp, const char* fmt, ...);
+
+int     printf(const char* fmt, ...);
+
+int main()
+{
+	void* fp = fopen("1.txt", "r");
+	if (!fp) {
+		printf("fp: %p\n", fp);
+		return -1;
+	}
+
+	char* s[64];
+
+	int n = fscanf(fp, "%s", s);
+
+	printf("s: %s, n: %d\n", s, n);
+
+	fclose(fp);
+	return 0;
+}
diff --git a/examples/main_argv.c b/examples/main_argv.c
new file mode 100644
index 0000000..fe50ca8
--- /dev/null
+++ b/examples/main_argv.c
@@ -0,0 +1,11 @@
+
+int printf(const char* fmt, ...);
+
+int main(int argc, char** argv, char** envp)
+{
+	int i;
+	for (i = 0; i < argc; i++)
+		printf("%s\n", argv[i]);
+
+	return 0;
+}
diff --git a/lib/_start.o b/lib/_start.o
index bca4a4de7cf737a07cbc8749bcd766dd51737ce1..38dbb233c43dc0328307640a799c60ef3200f718 100644
GIT binary patch
delta 113
zcmX@X_JD1IhEW0|0~|PjSq=;w4D1XZozFa)k8yZ(e)8zH@@PK9;nDiP^ovKgjmks^
zqlqOgjM5W-u4gouypqv;vH~;5<QI$<j0KYwne2gNBA8srWY5IFIQbEi9izr%MP_vX
D+zTL8

delta 101
zcmaFBc7kn!hJ*(r0~|PjSq=;w4D1XOql_kYwJ|bI7Gzw{C^7jUqdC(LhRMGe?HD5_
i7K%>}VA6mvCV&`|cQV;Cy#Pux*>MU$4KxJmkp}=$0vC1w

diff --git a/lib/_start.s b/lib/_start.s
index a5ba655..2df9e03 100644
--- a/lib/_start.s
+++ b/lib/_start.s
@@ -2,8 +2,19 @@
 .global _start, main
 
 _start:
+	mov  %rsp, %rsi
+	add  $8,   %rsi   # argv
+	mov  %rsi, %rdx
+1:
+	mov  (%rdx), %rdi
+	add  $8,    %rdx  # envp
+	test %rdi,  %rdi
+	jnz  1b
+
+	mov  (%rsp), %rdi # argc
+
 	call main
 	mov  %rax, %rdi
 	mov  $60,  %rax
 	syscall
-.fill 7, 1, 0
+.fill 5, 1, 0
-- 
2.25.1