Update publish arm64 hello world

2 files changed, 27 insertions, 26 deletions

diff --git a/md/writeup.md b/md/writeup.md
index a112bd7..39aa8b1 100644
--- a/md/writeup.md
+++ b/md/writeup.md
@@ -30,6 +30,7 @@ title: Writeup page
 [Running disk images in QEMU](writeup/running_disk_images_in_qemu.md)  
 [Mqueue IPC example](writeup/mqueue_ipc_example.md)  
 [Swift OCR example](writeup/swift_ocr_example.md)  
+[ARM64 assembly hello world](writeup/arm64_assembly_hello_world.md)  
 <!--[Writing mount utility](writeup/writing_mount_utility.md)-->
 
 
@@ -96,6 +97,7 @@ title: Writeup page
 [Sauerbraten patching and cheating](writeup/sauerbraten_patching_and_cheating.md)  
 [Scan memory for variable](writeup/scan_memory_for_variable.md)  
 
+
 ### Archive OpenWRT  
 [Building OpenWRT for RTL8196C](writeup/building_openwrt_for_rtl8196c.md)  
 [RTL8196C support for OpenWRT](writeup/rtl8196c_support_for_openwrt.md)  
diff --git a/md/writeup/arm64_assembly_hello_world.md b/md/writeup/arm64_assembly_hello_world.md
index 5601b89..f3bc452 100644
--- a/md/writeup/arm64_assembly_hello_world.md
+++ b/md/writeup/arm64_assembly_hello_world.md
@@ -10,7 +10,7 @@ is how to compile hello world for raspberry pi 4, as its supports
 ARMv8 instruction set. Second example is how to run assembly on 
 Apple M1 chip that also supports ARMv8 instruction set
 
-Two assembly examples are equivalent to C code
+The two assembly examples are equivalent to C code
 
 ```c
 int main() {
@@ -29,7 +29,7 @@ os run command
 uname
 ```
 
-Architecture shown as aarch64 good enoughs to indicate that os ir 64bit
+Architecture shown as aarch64 enoughs to indicate that os ir 64bit
 ```
 Linux raspberrypi 5.4.42-v8+ #1319 SMP PREEMPT Wed May 20 14:18:56 BST 2020 aarch64 GNU/Linux
 ```
@@ -39,9 +39,9 @@ Linux raspberrypi 5.4.42-v8+ #1319 SMP PREEMPT Wed May 20 14:18:56 BST 2020 aarc
 .data
 
 /* Data segment: define our message string and calculate its length. */
-msg:
+helloworld:
     .ascii        "Hello, ARM64!\n"
-len = . - msg
+helloworld_len = . - helloworld
 
 .text
 
@@ -49,21 +49,21 @@ len = . - msg
 .globl _start
 _start:
     /* syscall write(int fd, const void *buf, size_t count) */
-    mov     x0, #1      /* fd := STDOUT_FILENO */
-    ldr     x1, =msg    /* buf := msg */
-    ldr     x2, =len    /* count := len */
-    mov     w8, #64     /* write is syscall #64 */
-    svc     #0          /* invoke syscall */
+    mov     x0, #1              /* fd := STDOUT_FILENO */
+    ldr     x1, =helloworld     /* buf := msg */
+    ldr     x2, =helloworld_len /* count := len */
+    mov     w8, #64             /* write is syscall #64 */
+    svc     #0                  /* invoke syscall */
 
     /* syscall exit(int status) */
-    mov     x0, #0      /* status := 0 */
-    mov     w8, #93     /* exit is syscall #1 */
-    svc     #0          /* invoke syscall */
+    mov     x0, #0               /* status := 0 */
+    mov     w8, #93              /* exit is syscall #1 */
+    svc     #0                   /* invoke syscall */
 ```
 
 ### Compile
 
-Too compile check if there is installed gnu gcc, other compilers such as clang also 
+Too compile check if you have installed gnu gcc, other compilers such as clang also 
 should work perfectly fine.
 
 ```makefile
@@ -78,24 +78,23 @@ should work perfectly fine.
 
 ```asm
 .global _start            // Provide program starting address to linker
-.align 2            // Make sure everything is aligned properly
+.align 2                  // Make sure everything is aligned properly
 
-// Setup the parameters to print hello world
-// and then call the Kernel to do it.
+/* syscall write(int fd, const void *buf, size_t count) */
 _start: 
-    mov    X0, #1        // 1 = StdOut
+    mov    X0, #1         // 1 = StdOut
     adr    X1, helloworld     // string to print
-    mov    X2, #13            // length of our string
-    mov    X16, #4        // Unix write system call
-    svc    #0x80        // Call kernel to output the string
+    mov    X2, helloworld_len // length of our string
+    mov    X16, #4            // Unix write system call
+    svc    #0x80              // Call kernel to output the string
 
-// Setup the parameters to exit the program
-// and then call the kernel to do it.
-    mov     X0, #0        // Use 0 return code
-    mov     X16, #1        // System call number 1 terminates this program
-    svc     #0x80        // Call kernel to terminate the program
+/* syscall exit(int status) */
+    mov     X0, #0            // Use 0 return code
+    mov     X16, #1           // System call number 1 terminates this program
+    svc     #0x80             // Call kernel to terminate the program
 
-helloworld:      .ascii  "Hello World!\n"
+helloworld:      .ascii  "Hello, ARM64!\n"
+helloworld_len = . - helloworld
 ```
 
 ### Compile