Add new code

Signed-off-by: Carlos Maiolino <[email protected]>

1 files changed, 34 insertions, 0 deletions

diff --git a/PGU/CHAP8/printcall.s b/PGU/CHAP8/printcall.s
new file mode 100644
index 0000000..2d50e73
--- /dev/null
+++ b/PGU/CHAP8/printcall.s
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+# Just an example of calling printf() using ASM
+
+.section .data
+	firststring:
+	 .ascii "Hello! %s is a %s who lives the number %d\n\0"
+	name:
+	 .ascii "Maiolino\0"
+	personstring:
+	 .ascii "person\0"
+
+	numberloved:
+	 .long 123
+
+.section .text
+.globl _start
+
+	# Recall we are using x86_64 ABI here, so we pass arguments through
+	# registers instead of on the stack.
+
+_start:
+	movq $firststring, %rdi
+	movq $name, %rsi
+	movq $personstring, %rdx
+
+	# We don't use $numberloved here because $ sign means 'immediate'
+	# addressing. Here we want the 'CONTENT' pointed by label 'numberloved'
+	# so, we use 'direct' addressing, by ommiting the $ sign, so we get the
+	# information "pointed by" the label numberloved itself.
+	movq numberloved, %rcx
+	call printf
+
+	movq $0, %rdi
+	call exit
+