ChangeLog:

- big commit.

libc/include/sprinter_mem.h

@@ -47,23 +47,47 @@
  *   n     : 1..255
  *   ret   : blk_id (1..255) on success; 0 on failure with errno set.
  * The id is opaque — pass it to mem_get_page() and mem_free_block(). */
-uint8_t mem_alloc_pages(uint8_t n);
+uint8_t mem_alloc_pages_estex(uint8_t n);
+uint8_t mem_alloc_pages_bios(uint8_t n);
 
 /* Release a block previously returned by mem_alloc_pages().
  * On error errno is set (e.g. EINVAL for unknown id).  Double-free is
  * NOT idempotent: the second call sets errno. */
-void    mem_free_block(uint8_t blk_id);
+void    mem_free_block_estex(uint8_t blk_id);
+void    mem_free_block_bios(uint8_t blk_id);
 
 /* Translate (block, page-index) into a physical page number suitable
  * for sprinter_page_w1/w2/w3() or the bank_*() helpers below.
  *   blk_id: from mem_alloc_pages()
  *   idx   : 0..(n-1)
  *   ret   : physical page (1..255) on success; 0 on failure (errno set). */
-uint8_t mem_get_page(uint8_t blk_id, uint8_t idx);
+uint8_t mem_get_page_bios(uint8_t blk_id, uint8_t idx);
 
 /* Query the EMM allocator state.  Both pointers must be non-NULL.
  * Cannot fail (no error path). */
-void    mem_info(uint16_t *total, uint16_t *free_pages);
+void    mem_info_estex(uint16_t *total, uint16_t *free_pages);
+void    mem_info_bios(uint16_t *total, uint16_t *free_pages);
+
+#define MEM_MANAGE_MODE_BIOS
+
+#ifdef MEM_MANAGE_MODE_ESTEX
+
+#define mem_alloc_pages   mem_alloc_pages_estex
+#define mem_free_block    mem_free_block_estex
+#define mem_info          mem_info_estex
+
+#define mem_get_page mem_get_page_bios
+
+#elif defined MEM_MANAGE_MODE_BIOS
+
+#define mem_alloc_pages   mem_alloc_pages_bios
+#define mem_free_block    mem_free_block_bios
+#define mem_info          mem_info_bios
+
+#define mem_get_page mem_get_page_bios
+
+#endif
+
 
 /* ===================================================================
  * Far-page accessors via window 3 (base 0xC000, port 0xE2)