[SeaBIOS] [PATCH 1/8] Use the e-segment instead of the 9-segment for bios "low mem".
Kevin O'Connor
kevin at koconnor.net
Mon May 14 05:33:59 CEST 2012
Use the e-segment for ZoneLow allocations. There is plenty of
e-segment space (there has been since SeaBIOS supported code
relocation), while using the 9-segment space can impact old real-mode
applications.
Signed-off-by: Kevin O'Connor <kevin at koconnor.net>
---
src/config.h | 1 +
src/optionroms.c | 14 +-----
src/pmm.c | 116 ++++++++++++-----------------------------------------
src/shadow.c | 4 +-
src/util.h | 2 +-
5 files changed, 34 insertions(+), 103 deletions(-)
diff --git a/src/config.h b/src/config.h
index bbacae7..521469b 100644
--- a/src/config.h
+++ b/src/config.h
@@ -38,6 +38,7 @@
#define BUILD_ROM_START 0xc0000
#define BUILD_BIOS_ADDR 0xf0000
#define BUILD_BIOS_SIZE 0x10000
+#define BUILD_LOWMEM_SIZE 0x8000
// 32KB for shadow ram copying (works around emulator deficiencies)
#define BUILD_BIOS_TMP_ADDR 0x30000
#define BUILD_SMM_INIT_ADDR 0x38000
diff --git a/src/optionroms.c b/src/optionroms.c
index 06db1c1..5ce8af8 100644
--- a/src/optionroms.c
+++ b/src/optionroms.c
@@ -16,12 +16,10 @@
#include "paravirt.h" // qemu_cfg_*
#include "optionroms.h" // struct rom_header
-/****************************************************************
- * Definitions
- ****************************************************************/
-
// The end of the last deployed rom.
u32 RomEnd = BUILD_ROM_START;
+// The maximum memory location a rom may extend to.
+u32 RomTop;
/****************************************************************
@@ -120,15 +118,9 @@ get_pci_rom(struct rom_header *rom)
return pd;
}
-// Return start of code in 0xc0000-0xf0000 space.
-static inline u32 _max_rom(void) {
- extern u8 code32flat_start[], code32init_end[];
- return CONFIG_RELOCATE_INIT ? (u32)code32init_end : (u32)code32flat_start;
-}
// Return the memory position up to which roms may be located.
static inline u32 max_rom(void) {
- u32 end = _max_rom();
- return end > BUILD_BIOS_ADDR ? BUILD_BIOS_ADDR : end;
+ return RomTop;
}
// Copy a rom to its permanent location below 1MiB
diff --git a/src/pmm.c b/src/pmm.c
index c649fd8..1648bf2 100644
--- a/src/pmm.c
+++ b/src/pmm.c
@@ -9,6 +9,7 @@
#include "memmap.h" // struct e820entry
#include "farptr.h" // GET_FARVAR
#include "biosvar.h" // GET_BDA
+#include "optionroms.h" // OPTION_ROM_ALIGN
// Information on a reserved area.
struct allocinfo_s {
@@ -164,6 +165,15 @@ findLast(struct zone_s *zone)
* Setup
****************************************************************/
+// Return start of code in 0xc0000-0xf0000 space.
+static inline u32 lowmemend(void) {
+ extern u8 code32flat_start[], code32init_end[];
+ u32 end = CONFIG_RELOCATE_INIT ? (u32)code32init_end : (u32)code32flat_start;
+ return end > BUILD_BIOS_ADDR ? BUILD_BIOS_ADDR : end;
+}
+
+#define OPROM_HEADER_RESERVE 16
+
void
malloc_setup(void)
{
@@ -194,7 +204,9 @@ malloc_setup(void)
// Populate other regions
addSpace(&ZoneTmpLow, (void*)BUILD_STACK_ADDR, (void*)BUILD_EBDA_MINIMUM);
addSpace(&ZoneFSeg, BiosTableSpace, &BiosTableSpace[CONFIG_MAX_BIOSTABLE]);
- addSpace(&ZoneLow, (void*)BUILD_LOWRAM_END, (void*)BUILD_LOWRAM_END);
+ u32 lowend = lowmemend();
+ RomTop = ALIGN_DOWN(lowend-BUILD_LOWMEM_SIZE, OPTION_ROM_ALIGN);
+ addSpace(&ZoneLow, (void*)RomTop + OPROM_HEADER_RESERVE, (void*)lowend);
if (highram) {
addSpace(&ZoneHigh, (void*)highram
, (void*)highram + CONFIG_MAX_HIGHTABLE);
@@ -232,12 +244,21 @@ malloc_finalize(void)
ASSERT32FLAT();
dprintf(3, "malloc finalize\n");
- // Reserve more low-mem if needed.
- u32 endlow = GET_BDA(mem_size_kb)*1024;
- add_e820(endlow, BUILD_LOWRAM_END-endlow, E820_RESERVED);
+ // Place an optionrom signature around used low mem area.
+ struct allocinfo_s *info = findLast(&ZoneLow);
+ u32 base = BUILD_BIOS_ADDR;
+ if (info && info->allocend < (void*)BUILD_BIOS_ADDR) {
+ base = ALIGN_DOWN((u32)info->allocend - OPROM_HEADER_RESERVE
+ , OPTION_ROM_ALIGN);
+ struct rom_header *dummyrom = (void*)base;
+ dummyrom->signature = OPTION_ROM_SIGNATURE;
+ dummyrom->size = (BUILD_BIOS_ADDR - base) / 512;
+ }
+ memset((void*)RomEnd, 0, base-RomEnd);
+ dprintf(1, "Space available for UMB: %08x-%08x\n", RomEnd, base);
// Give back unused high ram.
- struct allocinfo_s *info = findLast(&ZoneHigh);
+ info = findLast(&ZoneHigh);
if (info) {
u32 giveback = ALIGN_DOWN(info->allocend - info->dataend, PAGE_SIZE);
add_e820((u32)info->dataend, giveback, E820_RAM);
@@ -247,89 +268,6 @@ malloc_finalize(void)
/****************************************************************
- * ebda movement
- ****************************************************************/
-
-// Move ebda
-static int
-relocate_ebda(u32 newebda, u32 oldebda, u8 ebda_size)
-{
- u32 lowram = GET_BDA(mem_size_kb) * 1024;
- if (oldebda != lowram)
- // EBDA isn't at end of ram - give up.
- return -1;
-
- // Do copy
- memmove((void*)newebda, (void*)oldebda, ebda_size * 1024);
-
- // Update indexes
- dprintf(1, "ebda moved from %x to %x\n", oldebda, newebda);
- SET_BDA(mem_size_kb, newebda / 1024);
- SET_BDA(ebda_seg, FLATPTR_TO_SEG(newebda));
- return 0;
-}
-
-// Support expanding the ZoneLow dynamically.
-static void
-zonelow_expand(u32 size, u32 align)
-{
- struct allocinfo_s *info = findLast(&ZoneLow);
- if (!info)
- return;
- u32 oldpos = (u32)info->allocend;
- u32 newpos = ALIGN_DOWN(oldpos - size, align);
- u32 bottom = (u32)info->dataend;
- if (newpos >= bottom && newpos <= oldpos)
- // Space already present.
- return;
- u16 ebda_seg = get_ebda_seg();
- u32 ebda_pos = (u32)MAKE_FLATPTR(ebda_seg, 0);
- u8 ebda_size = GET_EBDA2(ebda_seg, size);
- u32 ebda_end = ebda_pos + ebda_size * 1024;
- if (ebda_end != bottom)
- // Something else is after ebda - can't use any existing space.
- newpos = ALIGN_DOWN(ebda_end - size, align);
- u32 newbottom = ALIGN_DOWN(newpos, 1024);
- u32 newebda = ALIGN_DOWN(newbottom - ebda_size * 1024, 1024);
- if (newebda < BUILD_EBDA_MINIMUM)
- // Not enough space.
- return;
-
- // Move ebda
- int ret = relocate_ebda(newebda, ebda_pos, ebda_size);
- if (ret)
- return;
-
- // Update zone
- if (ebda_end == bottom) {
- info->data = (void*)newbottom;
- info->dataend = (void*)newbottom;
- } else
- addSpace(&ZoneLow, (void*)newbottom, (void*)ebda_end);
-}
-
-// Check if can expand the given zone to fulfill an allocation
-static void *
-allocExpandSpace(struct zone_s *zone, u32 size, u32 align
- , struct allocinfo_s *fill)
-{
- void *data = allocSpace(zone, size, align, fill);
- if (data || zone != &ZoneLow)
- return data;
-
- // Make sure to not move ebda while an optionrom is running.
- if (unlikely(wait_preempt())) {
- data = allocSpace(zone, size, align, fill);
- if (data)
- return data;
- }
-
- zonelow_expand(size, align);
- return allocSpace(zone, size, align, fill);
-}
-
-
-/****************************************************************
* tracked memory allocations
****************************************************************/
@@ -352,7 +290,7 @@ pmm_malloc(struct zone_s *zone, u32 handle, u32 size, u32 align)
}
// Find and reserve space for main allocation
- void *data = allocExpandSpace(zone, size, align, &detail->datainfo);
+ void *data = allocSpace(zone, size, align, &detail->datainfo);
if (!data) {
freeSpace(&detail->detailinfo);
return NULL;
diff --git a/src/shadow.c b/src/shadow.c
index c0c8cc2..70f04c5 100644
--- a/src/shadow.c
+++ b/src/shadow.c
@@ -83,8 +83,8 @@ make_bios_readonly_intel(u16 bdf, u32 pam0)
for (i=0; i<6; i++) {
u32 mem = BUILD_ROM_START + i * 32*1024;
u32 pam = pam0 + 1 + i;
- if (RomEnd <= mem + 16*1024) {
- if (RomEnd > mem)
+ if (RomEnd <= mem + 16*1024 || RomTop <= mem + 32*1024) {
+ if (RomEnd > mem && RomTop > mem + 16*1024)
pci_config_writeb(bdf, pam, 0x31);
break;
}
diff --git a/src/util.h b/src/util.h
index 70d3c4c..04de66b 100644
--- a/src/util.h
+++ b/src/util.h
@@ -400,7 +400,7 @@ void call_bcv(u16 seg, u16 ip);
void optionrom_setup(void);
void vga_setup(void);
void s3_resume_vga_init(void);
-extern u32 RomEnd;
+extern u32 RomEnd, RomTop;
extern int ScreenAndDebug;
// bootsplash.c
--
1.7.6.5
More information about the SeaBIOS
mailing list