Add objstore code, tests

include/objstore.h

@@ -0,0 +1,23 @@
+#ifndef _OBJSTORE_H_
+#define _OBJSTORE_H_
+
+#include "apple2.mem.h"
+#include "vm_bits.h"
+
+typedef struct {
+    char header[4];
+    vm_8bit apple2_disk2_rom[APPLE2_DISK2_ROM_SIZE];
+    vm_8bit apple2_sys_rom[0x4000];
+    vm_8bit apple2_sysfont[APPLE2_SYSFONT_SIZE];
+} objstore;
+
+extern int objstore_init();
+
+#define OBJSTORE_DECL(x) \
+    const vm_8bit *objstore_##x()
+
+OBJSTORE_DECL(apple2_disk2_rom);
+OBJSTORE_DECL(apple2_sys_rom);
+OBJSTORE_DECL(apple2_sysfont);
+
+#endif

sources.cmake

@@ -13,6 +13,7 @@ set(erc_sources
 	mos6502.exec.c
 	mos6502.loadstor.c
 	mos6502.stat.c
+	objstore.c
 	option.c
 	vm_bitfont.c
 	vm_screen.c

src/objstore.c

@@ -0,0 +1,73 @@
+/*
+ * obj.c
+ */
+
+#include <zlib.h>
+
+#include "objstore.h"
+#include "objstore_data.h"
+
+/*
+ * This is data that we expect to find in the store_data variable that
+ * is defined in objstore_data.h.
+ */
+#define HEADER_DATA "hope"
+
+/*
+ * Our object store. Just a simple struct that we pull data out from.
+ */
+static objstore store;
+
+/*
+ * This function will set up the store variable so that it contains
+ * useful information rather than garbage data from the stack. It does
+ * so with a simply memcpy from store_data directly into store, such
+ * that the store data itself can be aligned for access.
+ */
+int
+objstore_init()
+{
+    int cmp;
+
+    // We want to input some bad header data and compare with what
+    // eventually should get put into there by memcmp.
+    store.header[0] = 'h';
+    store.header[1] = 'e';
+    store.header[2] = 'y';
+    store.header[3] = '\0';
+
+    memcpy(&store, store_data, sizeof(store));
+
+    // Test if the header field data is exactly equivalent to that
+    // defined in HEADER_DATA. Note we use memcmp(), because the header
+    // field is an array of just 4 bytes; strcmp() and strncmp() have an
+    // expectation that both pointers will be directed at NUL-terminated
+    // strings, which is _not_ the case for store.header (but,
+    // incidentally, _is_ the case for HEADER_DATA!).
+    cmp = memcmp(store.header, HEADER_DATA,
+                 sizeof(store.header) / sizeof(char));
+
+    // If the two areas of memory were not a complete match...
+    if (cmp != 0) {
+        log_critical("Object store initialization failed with bad data");
+        return ERR_BADFILE;
+    }
+
+    return OK;
+}
+
+/*
+ * Something to simplify the very simple getter functions we use for
+ * getting data from the object store.
+ */
+#define OBJSTORE_DEFN(x) \
+    const vm_8bit *objstore_##x() { return store.x; }
+
+/*
+ * Note we have an extra semicolon on the end... this is mostly to avoid
+ * screwing up my indent, to be honest. But C will ignore the
+ * semicolons, so all is well.
+ */
+OBJSTORE_DEFN(apple2_sys_rom);
+OBJSTORE_DEFN(apple2_disk2_rom);
+OBJSTORE_DEFN(apple2_sysfont);

tests/objstore.c

@@ -0,0 +1,9 @@
+#include <criterion/criterion.h>
+
+#include "log.h"
+#include "objstore.h"
+
+Test(objstore, init)
+{
+    cr_assert_eq(objstore_init(), OK);
+}