[Qemu-devel] [PATCH] pc_sysfw: Always use alias for ISA BIOS region

[Jan Kiszka <jan.kiszka@web.de>]

From: Jan Kiszka <jan.kiszka@siemens.com>

This is no technical reason (anymore) for copying the ISA BIOS from the
original region. Instead, refactor pc_isa_bios_init to serve both pflash
and old-style BIOS setup.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 hw/pc_sysfw.c |   42 +++++++++---------------------------------
 1 files changed, 9 insertions(+), 33 deletions(-)

diff --git a/hw/pc_sysfw.c b/hw/pc_sysfw.c
index 9d7c5f4..07627df 100644
--- a/hw/pc_sysfw.c
+++ b/hw/pc_sysfw.c
@@ -41,36 +41,24 @@ typedef struct PcSysFwDevice {
 } PcSysFwDevice;
 
 static void pc_isa_bios_init(MemoryRegion *rom_memory,
-                             MemoryRegion *flash_mem,
-                             int ram_size)
+                             MemoryRegion *bios)
 {
+    uint64_t bios_size = memory_region_size(bios);
     int isa_bios_size;
     MemoryRegion *isa_bios;
-    uint64_t flash_size;
-    void *flash_ptr, *isa_bios_ptr;
-
-    flash_size = memory_region_size(flash_mem);
 
     /* map the last 128KB of the BIOS in ISA space */
-    isa_bios_size = flash_size;
+    isa_bios_size = bios_size;
     if (isa_bios_size > (128 * 1024)) {
         isa_bios_size = 128 * 1024;
     }
     isa_bios = g_malloc(sizeof(*isa_bios));
-    memory_region_init_ram(isa_bios, "isa-bios", isa_bios_size);
-    vmstate_register_ram_global(isa_bios);
+    memory_region_init_alias(isa_bios, "isa-bios", bios,
+                             bios_size - isa_bios_size, isa_bios_size);
     memory_region_add_subregion_overlap(rom_memory,
                                         0x100000 - isa_bios_size,
                                         isa_bios,
                                         1);
-
-    /* copy ISA rom image from top of flash memory */
-    flash_ptr = memory_region_get_ram_ptr(flash_mem);
-    isa_bios_ptr = memory_region_get_ram_ptr(isa_bios);
-    memcpy(isa_bios_ptr,
-           ((uint8_t*)flash_ptr) + (flash_size - isa_bios_size),
-           isa_bios_size);
-
     memory_region_set_readonly(isa_bios, true);
 }
 
@@ -129,14 +117,14 @@ static void pc_system_flash_init(MemoryRegion *rom_memory,
                                          1, 0x0000, 0x0000, 0x0000, 0x0000, 0);
     flash_mem = pflash_cfi01_get_memory(system_flash);
 
-    pc_isa_bios_init(rom_memory, flash_mem, size);
+    pc_isa_bios_init(rom_memory, flash_mem);
 }
 
 static void old_pc_system_rom_init(MemoryRegion *rom_memory)
 {
     char *filename;
-    MemoryRegion *bios, *isa_bios;
-    int bios_size, isa_bios_size;
+    MemoryRegion *bios;
+    int bios_size;
     int ret;
 
     /* BIOS load */
@@ -167,19 +155,7 @@ static void old_pc_system_rom_init(MemoryRegion *rom_memory)
         g_free(filename);
     }
 
-    /* map the last 128KB of the BIOS in ISA space */
-    isa_bios_size = bios_size;
-    if (isa_bios_size > (128 * 1024)) {
-        isa_bios_size = 128 * 1024;
-    }
-    isa_bios = g_malloc(sizeof(*isa_bios));
-    memory_region_init_alias(isa_bios, "isa-bios", bios,
-                             bios_size - isa_bios_size, isa_bios_size);
-    memory_region_add_subregion_overlap(rom_memory,
-                                        0x100000 - isa_bios_size,
-                                        isa_bios,
-                                        1);
-    memory_region_set_readonly(isa_bios, true);
+    pc_isa_bios_init(rom_memory, bios);
 
     /* map all the bios at the top of memory */
     memory_region_add_subregion(rom_memory,
-- 
1.7.3.4