Initial commit: try make binaries

2025-09-14 15:34:16 +02:00
commit 789fa1306c
8 changed files with 364 additions and 0 deletions
--- a/crc16.c
+++ b/crc16.c
@@ -0,0 +1,34 @@
+#include <stdint.h>
+
+#define kDataAddr ((uint8_t*) 0x0000)
+
+uint16_t crc16(int data_len) {
+    const uint8_t* data = kDataAddr;
+
+    uint16_t crc = 0xFFFF;
+    for (unsigned int i = 0; i < data_len; ++i) {
+        uint16_t dbyte = data[i];
+        crc ^= dbyte << 8;
+        for (unsigned char j = 0; j < 8; ++j) {
+            uint16_t mix = crc & 0x8000;
+            crc = (crc << 1);
+            if (mix)
+                crc = crc ^ 0x1021;
+        }
+    }
+    return crc;
+}
+
+asm (
+        ".global main      \n"
+        "main:             \n"
+        "  push %bp        \n"
+        "  mov %sp, %bp    \n"
+        "  mov 6(%bp), %si \n"
+        "  push (%si)      \n"
+        "  call crc16      \n"
+        "  mov 8(%bp), %di \n"
+        "  mov %ax, (%di)  \n"
+        "  pop %bp         \n"
+        "  lret $4         \n"
+        );