From 9ddea720055aba55b30a661e99fd344fbfcaa387 Mon Sep 17 00:00:00 2001
From: afify <hassan@afify.dev>
Date: Fri, 6 Nov 2020 14:03:54 +0300
Subject: [PATCH] [feat] print julian, create util.s

- use timestamp to julian:
	return ( unixsecs / 86400.0 ) + 2440587.5;
- move _printRAX to util.s
---
 Makefile              |   2 +-
 azan-nasm.s           | 108 +++++++++++++++++++-------------------------------
 config.mk             |   2 +-
 azan-nasm.s => util.s |  22 +---------
 4 files changed, 44 insertions(+), 90 deletions(-)
 rewrite azan-nasm.s (69%)
 copy azan-nasm.s => util.s (61%)

diff --git a/Makefile b/Makefile
index 5b40bcb..9fd722c 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@
 include config.mk
 
 BIN = azan-nasm
-SRC = ${BIN}.s
+SRC = ${BIN}.s util.s
 OBJ = ${SRC:.s=.o}
 
 all: options ${BIN}
diff --git a/azan-nasm.s b/azan-nasm.s
dissimilarity index 69%
index 3001a9f..c4b0d6b 100644
--- a/azan-nasm.s
+++ b/azan-nasm.s
@@ -1,68 +1,40 @@
-; See LICENSE file for copyright and license details.
-; azan-nasm is simple muslim prayers calculator.
-; print next prayer left duration or today's all prayers.
-
-BITS 64
-%include "syscalls.s"
-%include "macros.s"
-CHECK_OPENBSD
-
-section .bss
-	digitSpace: resb 100
-	digitSpacePos: resb 8
-	current_time: resb 12
-
-section .text
-	global _start
-
-_start:
-	mov rax, SYS_gettimeofday
-	mov rdi, current_time
-	mov rsi, rsi
-	syscall
-
-	mov rax, [current_time]
-
-	call _printRAX
-	EEXIT EXIT_SUCCESS
-
-_printRAX:
-	mov rcx, digitSpace
-	mov rbx, 10
-	mov [rcx], rbx
-	inc rcx
-	mov [digitSpacePos], rcx
-
-_printRAXLoop:
-	mov rdx, 0
-	mov rbx, 10
-	div rbx
-	push rax
-	add rdx, 48
-
-	mov rcx, [digitSpacePos]
-	mov [rcx], dl
-	inc rcx
-	mov [digitSpacePos], rcx
-	
-	pop rax
-	cmp rax, 0
-	jne _printRAXLoop
-
-_printRAXLoop2:
-	mov rcx, [digitSpacePos]
-
-	mov rax, SYS_write
-	mov rdi, 1
-	mov rsi, rcx
-	mov rdx, 1
-	syscall
-
-	mov rcx, [digitSpacePos]
-	dec rcx
-	mov [digitSpacePos], rcx
-
-	cmp rcx, digitSpace
-	jge _printRAXLoop2
-
-	ret
+; See LICENSE file for copyright and license details.
+; azan-nasm is simple muslim prayers calculator.
+; print next prayer left duration or today's all prayers.
+
+BITS 64
+%include "syscalls.s"
+%include "macros.s"
+CHECK_OPENBSD
+
+section .bss
+	timestamp: resb 12
+	julian: resb 12
+	equation_of_time: resb 12
+	res_char: resb 1
+	res_hour: resb 2
+	res_min: resb 2
+section .rodata
+	julian_1970: dq 0x41429ec5c0000000 ; double 2440587.5
+	sec_in_day: dq 0x40f5180000000000 ; double 86400
+
+section .text
+	global _start
+	extern _printRAX
+
+_start:
+; get_timestamp:
+	mov rax, SYS_gettimeofday ;sys_gettimeofday(
+	mov rdi, timestamp        ;struct timeval *tv,
+	mov rsi, rsi              ;struct timezone* tz
+	syscall                   ;)
+
+; calc_julian:
+	mov rax, [timestamp]   ; mov value of timestamp in rax
+	mov rbx, sec_in_day    ; rbx = SEC_IN_DAY
+	div rbx                ; timestamp / SEC_IN_DAY
+	add rax, 2440587
+	mov [julian], rax      ; save result of division in julian
+
+	call _printRAX ;util.s
+	EEXIT EXIT_SUCCESS
diff --git a/config.mk b/config.mk
index 301e364..f5ed4ce 100644
--- a/config.mk
+++ b/config.mk
@@ -9,7 +9,7 @@ MANPREFIX = ${PREFIX}/share/man
 
 # flags
 AFLAGS  = -f elf64 -w+all -D$$(uname)
-LFLAGS  = -m elf_x86_64 -no-pie
+LFLAGS  = -m elf_x86_64 -s -no-pie
 
 # compiler and linker
 ASM  = nasm
diff --git a/azan-nasm.s b/util.s
similarity index 61%
copy from azan-nasm.s
copy to util.s
index 3001a9f..a65c6be 100644
--- a/azan-nasm.s
+++ b/util.s
@@ -1,30 +1,12 @@
-; See LICENSE file for copyright and license details.
-; azan-nasm is simple muslim prayers calculator.
-; print next prayer left duration or today's all prayers.
-
 BITS 64
 %include "syscalls.s"
-%include "macros.s"
-CHECK_OPENBSD
-
+%idefine rip rel $
 section .bss
 	digitSpace: resb 100
 	digitSpacePos: resb 8
-	current_time: resb 12
 
 section .text
-	global _start
-
-_start:
-	mov rax, SYS_gettimeofday
-	mov rdi, current_time
-	mov rsi, rsi
-	syscall
-
-	mov rax, [current_time]
-
-	call _printRAX
-	EEXIT EXIT_SUCCESS
+	global _printRAX
 
 _printRAX:
 	mov rcx, digitSpace
-- 
2.11.4.GIT