ChangeLog:

- big commit.

libc/include/conio.h

@@ -201,4 +201,36 @@ enum {
 #define COLOR_BLINK    0x80u
 #define COLOR(fg, bg)  ((uint8_t)((((bg) & 0x07) << 4) | ((fg) & 0x0F)))
 
+/* Text-mode palette.  The 16 logical CGA colours seen by COLOR(fg, bg)
+ * actually live in four 256-entry hardware palette planes indexed by the
+ * full 8-bit attribute byte:
+ *
+ *   TEXT_PAL_PAPER        — background colour, non-blink phase
+ *   TEXT_PAL_INK          — foreground colour, non-blink phase
+ *   TEXT_PAL_BLINK_PAPER  — background colour during the blink half-cycle
+ *   TEXT_PAL_BLINK_INK    — foreground colour during the blink half-cycle
+ *
+ * For non-blinking attributes (bit 7 = 0) all four planes display the
+ * same colours, so writing to PAPER/INK is enough. For blinking attrs
+ * (bit 7 = 1) the renderer alternates between the non-blink and blink
+ * planes — that's how flash is implemented in hardware.
+ *
+ * These wrappers add 4 to the plane index and forward to the low-level
+ * <palette.h> API (pal_load / pal_set_color / pal_get / pal_get_color).
+ * Use text_pal_reset() to restore the system default CGA palette. */
+#define TEXT_PAL_PAPER        0
+#define TEXT_PAL_INK          1
+#define TEXT_PAL_BLINK_PAPER  2
+#define TEXT_PAL_BLINK_INK    3
+
+void text_pal_load     (uint8_t plane, uint8_t start, uint8_t count,
+                        const uint8_t *bgr0);
+void text_pal_set_color(uint8_t plane, uint8_t attr,
+                        uint8_t r, uint8_t g, uint8_t b);
+void text_pal_get      (uint8_t plane, uint8_t start, uint8_t count,
+                        uint8_t *bgr0);
+void text_pal_get_color(uint8_t plane, uint8_t attr,
+                        uint8_t *r, uint8_t *g, uint8_t *b);
+void text_pal_reset    (void);
+
 #endif

libc/include/gfx.h

@@ -145,4 +145,15 @@ void    gfx_pal_load(uint8_t pal_num, uint8_t start, uint8_t count,
 void    gfx_pal_set (uint8_t pal_num, uint8_t idx,
                      uint8_t r, uint8_t g, uint8_t b);
 
+/* Read a contiguous block of entries back from a graphics palette. */
+void    gfx_pal_get (uint8_t pal_num, uint8_t start, uint8_t count,
+                     uint8_t *data);
+
+/* Read one entry into R, G, B pointers (any may be NULL). */
+void    gfx_pal_get_color(uint8_t pal_num, uint8_t idx,
+                          uint8_t *r, uint8_t *g, uint8_t *b);
+
+/* Restore the system default graphics palette (BIOS $A6, type=1). */
+void    gfx_pal_reset(void);
+
 #endif

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)