[Qemu-devel] [PATCH] get roms more room.

[Glauber Costa <glommer@redhat.com>]

This patch increases by 50 % the size available for option roms.
The main motivator is that some roms grew bigger than the 64k we
currently allocate for them (Hey, it's 2009!)

One example is the gpxe project, that produces some roms with 69k,
70k, etc. The space proposed by this patch actually makes it as
big as 84k. Probably still a fit for some time.

But there is no free lunch. This space must come from somewhere,
and we take it from vga rom space. Currently, our vga roms are
around 35k in size. With this patch, option rom space will begin
just after vga ends, aligned to the next 2k boundary.

Technicaly, we could do the same with the uper space (the bios itself),
but since bochs bios is already 128 k in size, I don't see an
urgent need to do it.

[ fix case for vgabioses smaller than 30k, by Carl-Daniel Hailfinger ]

Signed-off-by: Glauber Costa <glommer@redhat.com>
---
 hw/pc.c |   29 +++++++++++++++++++----------
 1 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/hw/pc.c b/hw/pc.c
index 69f25f3..f9cfd1f 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -763,7 +763,7 @@ static void pc_init1(ram_addr_t ram_size, int vga_ram_size,
 {
     char buf[1024];
     int ret, linux_boot, i;
-    ram_addr_t ram_addr, vga_ram_addr, bios_offset, vga_bios_offset;
+    ram_addr_t ram_addr, vga_ram_addr, bios_offset, vga_bios_offset, option_rom_start = 0;
     ram_addr_t below_4g_mem_size, above_4g_mem_size = 0;
     int bios_size, isa_bios_size, vga_bios_size;
     PCIBus *pci_bus;
@@ -774,6 +774,7 @@ static void pc_init1(ram_addr_t ram_size, int vga_ram_size,
     int index;
     BlockDriverState *hd[MAX_IDE_BUS * MAX_IDE_DEVS];
     BlockDriverState *fd[MAX_FD];
+    int using_vga = cirrus_vga_enabled || std_vga_enabled || vmsvga_enabled;
 
     if (ram_size >= 0xe0000000 ) {
         above_4g_mem_size = ram_size - 0xe0000000;
@@ -856,7 +857,7 @@ static void pc_init1(ram_addr_t ram_size, int vga_ram_size,
         exit(1);
     }
 
-    if (cirrus_vga_enabled || std_vga_enabled || vmsvga_enabled) {
+    if (using_vga) {
         /* VGA BIOS load */
         if (cirrus_vga_enabled) {
             snprintf(buf, sizeof(buf), "%s/%s", bios_dir, VGABIOS_CIRRUS_FILENAME);
@@ -874,12 +875,21 @@ vga_bios_error:
             fprintf(stderr, "qemu: could not load VGA BIOS '%s'\n", buf);
             exit(1);
         }
+	/* Round up vga bios size to the next 2k boundary */
+	vga_bios_size = (vga_bios_size + 2047) & ~2047;
+	option_rom_start = 0xc0000 + vga_bios_size;
 
         /* setup basic memory access */
-        cpu_register_physical_memory(0xc0000, 0x10000,
+        cpu_register_physical_memory(0xc0000, vga_bios_size,
                                      vga_bios_offset | IO_MEM_ROM);
     }
 
+    /* No point in placing option roms before this address, since bochs bios
+     * will only start looking for it at 0xc8000 */
+    if (option_rom_start < 0xc8000)
+	    option_rom_start = 0xc8000;
+
+
     /* map the last 128KB of the BIOS in ISA space */
     isa_bios_size = bios_size;
     if (isa_bios_size > (128 * 1024))
@@ -892,14 +902,14 @@ vga_bios_error:
         ram_addr_t option_rom_offset;
         int size, offset;
 
-        offset = 0;
+        offset = option_rom_start;
         if (linux_boot) {
             option_rom_offset = qemu_ram_alloc(TARGET_PAGE_SIZE);
             load_linux(phys_ram_base + option_rom_offset,
                        kernel_filename, initrd_filename, kernel_cmdline);
-            cpu_register_physical_memory(0xd0000, TARGET_PAGE_SIZE,
+            cpu_register_physical_memory(option_rom_start, TARGET_PAGE_SIZE,
                                          option_rom_offset | IO_MEM_ROM);
-            offset = TARGET_PAGE_SIZE;
+            offset += TARGET_PAGE_SIZE;
         }
 
         for (i = 0; i < nb_option_roms; i++) {
@@ -909,18 +919,17 @@ vga_bios_error:
                         option_rom[i]);
                 exit(1);
             }
-            if (size > (0x10000 - offset))
+            if (size > (0xe0000  - offset))
                 goto option_rom_error;
             option_rom_offset = qemu_ram_alloc(size);
             ret = load_image(option_rom[i], phys_ram_base + option_rom_offset);
             if (ret != size) {
             option_rom_error:
-                fprintf(stderr, "Too many option ROMS\n");
+                fprintf(stderr, "Could not fit %soption roms in available space\n", using_vga ? "VGA bios and " : "");
                 exit(1);
             }
             size = (size + 4095) & ~4095;
-            cpu_register_physical_memory(0xd0000 + offset,
-                                         size, option_rom_offset | IO_MEM_ROM);
+            cpu_register_physical_memory(offset, size, option_rom_offset | IO_MEM_ROM);
             offset += size;
         }
     }
-- 
1.6.2