Changeset b909777 in buchla-emu for emu/cpu.c

Timestamp:

07/20/2017 04:19:40 PM (7 years ago)

Author:

Thomas Lopatic <thomas@…>

Branches:

master

Children:

51b6cfd

Parents:

a06aa8b

Message:

Parse command line options. Load BIOS file.

File:

• emu/cpu.c (modified) (5 diffs)

emu/cpu.c

@@ -58 +58 @@
 static uint8_t rom_data[ROM_SIZE];
 
-static uint32_t ram_rd_beg;
-static uint32_t ram_rd_end;
-static uint32_t ram_wr_beg;
-static uint32_t ram_wr_end;
+static uint32_t ram_rd_beg = 0x10000000;
+static uint32_t ram_rd_end = 0x10000000;
+static uint32_t ram_wr_beg = 0x10000000;
+static uint32_t ram_wr_end = 0x10000000;
 
 static uint32_t rom_rd_beg;
@@ -94 +94 @@
 static void hw_init(void)
 {
+        ver("initializing hardware");
+
         for (int32_t i = 0; i < ARRAY_COUNT(hw_map); ++i) {
                 hw_map[i].init();
@@ -113 +115 @@
 
         return (addr - hw->addr_beg) / 2;
+}
+
+static void bios_init(const char *bios)
+{
+        ver("loading BIOS file %s", bios);
+
+        SDL_RWops *ops = SDL_RWFromFile(bios, "rb");
+
+        if (ops == NULL) {
+                fail("error while opening BIOS file %s", bios);
+        }
+
+        if (SDL_ReadBE16(ops) != 0x601b) {
+                fail("invalid BIOS file %s", bios);
+        }
+
+        uint32_t text_len = SDL_ReadBE32(ops);
+        uint32_t data_len = SDL_ReadBE32(ops);
+        uint32_t bss_len = SDL_ReadBE32(ops);
+
+        SDL_ReadBE32(ops);
+        SDL_ReadBE32(ops);
+
+        uint32_t text_loc = SDL_ReadBE32(ops);
+
+        SDL_ReadBE16(ops);
+
+        uint32_t data_loc = SDL_ReadBE32(ops);
+        uint32_t bss_loc = SDL_ReadBE32(ops);
+
+        ver("text 0x%x@0x%x data 0x%x@0x%x bss 0x%x@0x%x",
+                        text_len, text_loc, data_len, data_loc, bss_len, bss_loc);
+
+        size_t load_len = (size_t)SDL_RWsize(ops) - 36;
+
+        if (load_len != text_len + data_len) {
+                fail("corrupted BIOS file %s", bios);
+        }
+
+        size_t loaded = 0;
+
+        while (loaded < load_len) {
+                size_t n_rd = SDL_RWread(ops, rom_data + loaded, 1, load_len - loaded);
+
+                if (n_rd == 0) {
+                        fail("error while reading BIOS file %s", bios);
+                }
+
+                loaded += n_rd;
+        }
+
+        SDL_RWclose(ops);
 }
 
@@ -182 +236 @@
         if (reset) {
                 if (addr == 0) {
-                        return RESET_SP;
-                }
-
-                if (addr == 4) {
+                        addr += ROM_START;
+                }
+
+                else if (addr == 4) {
+                        addr += ROM_START;
                         reset = false;
-                        return RESET_PC;
-                }
-
-                fail("invalid reset sequence");
+                }
+                else {
+                        fail("invalid reset sequence");
+                }
         }
 
@@ -301 +356 @@
 }
 
-void cpu_loop(void)
-{
-        ver("initializing hardware");
+void cpu_loop(const char *bios)
+{
+        ver("entering CPU loop");
+
         hw_init();
+        bios_init(bios);
 
         ver("starting CPU");