Add new code

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

1 files changed, 52 insertions, 0 deletions

diff --git a/PGU/OLD/chapter3/min.s b/PGU/OLD/chapter3/min.s
new file mode 100644
index 0000000..9179be7
--- /dev/null
+++ b/PGU/OLD/chapter3/min.s
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+# This code has been originally copied from max.s
+
+# It has been modified to:
+#	- Find the smallest value, instead of the largest
+#	- Use Start/End addresses to delimit the boundaries of the number list
+#
+# %rax - holds the current element being examined
+# %rbx - Holds the smallest number
+
+.section .data
+
+# This version has 2 labels, one to point to the start of the list, and another
+# to point to the address right after it, so we can use it to search the list
+# boundary.
+
+data_items:
+	.quad 234,10,9,230,66,77,23,66,101,69,100
+data_end:
+
+.section .text
+
+.globl _start
+
+_start:
+
+# Using immediate mode with a label, will give you the ADDRESS of the
+# instruction/data it points to. Once the label itself contains an ADDRESS, the
+# immediate mode will give you the ADDRESS itself.
+
+# Using direct mode with a label, will give you the DATA into the address the
+# label points to. Once the label itself contains an address, the direct mode,
+# as expected will give you the DATA into the address pointed by the label.
+	movq	$data_items, %rax
+	cmpq	$data_end, %rax			# We need this check here in case
+	je	exit_loop_empty			# the items list is empty
+	movq	(%rax), %rbx
+
+	loop_start:
+		addq	$8, %rax		# We are using QuadWords, so 8 bytes
+		cmpq	$data_end, %rax
+		je	exit_loop
+
+		cmpq	(%rax), %rbx
+		jle	loop_start
+		movq	(%rax), %rbx
+		jmp	loop_start
+
+	exit_loop_empty:
+		movq	$255, %rbx
+	exit_loop:
+		movq	$1, %rax
+		int	$0x80