1 files changed, 312 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/gpxe/src/arch/i386/firmware/pcbios/memmap.c b/contrib/syslinux-4.02/gpxe/src/arch/i386/firmware/pcbios/memmap.c
new file mode 100644
index 0000000..8a30dba
--- /dev/null
+++ b/contrib/syslinux-4.02/gpxe/src/arch/i386/firmware/pcbios/memmap.c
@@ -0,0 +1,312 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <errno.h>
+#include <realmode.h>
+#include <bios.h>
+#include <memsizes.h>
+#include <gpxe/memmap.h>
+
+/**
+ * @file
+ *
+ * Memory mapping
+ *
+ */
+
+/** Magic value for INT 15,e820 calls */
+#define SMAP ( 0x534d4150 )
+
+/** An INT 15,e820 memory map entry */
+struct e820_entry {
+	/** Start of region */
+	uint64_t start;
+	/** Length of region */
+	uint64_t len;
+	/** Type of region */
+	uint32_t type;
+	/** Extended attributes (optional) */
+	uint32_t attrs;
+} __attribute__ (( packed ));
+
+#define E820_TYPE_RAM		1 /**< Normal memory */
+#define E820_TYPE_RESERVED	2 /**< Reserved and unavailable */
+#define E820_TYPE_ACPI		3 /**< ACPI reclaim memory */
+#define E820_TYPE_NVS		4 /**< ACPI NVS memory */
+
+#define E820_ATTR_ENABLED	0x00000001UL
+#define E820_ATTR_NONVOLATILE	0x00000002UL
+#define E820_ATTR_UNKNOWN	0xfffffffcUL
+
+#define E820_MIN_SIZE		20
+
+/** Buffer for INT 15,e820 calls */
+static struct e820_entry __bss16 ( e820buf );
+#define e820buf __use_data16 ( e820buf )
+
+/**
+ * Get size of extended memory via INT 15,e801
+ *
+ * @ret extmem		Extended memory size, in kB, or 0
+ */
+static unsigned int extmemsize_e801 ( void ) {
+	uint16_t extmem_1m_to_16m_k, extmem_16m_plus_64k;
+	uint16_t confmem_1m_to_16m_k, confmem_16m_plus_64k;
+	unsigned int flags;
+	unsigned int extmem;
+
+	__asm__ __volatile__ ( REAL_CODE ( "stc\n\t"
+					   "int $0x15\n\t"
+					   "pushfw\n\t"
+					   "popw %w0\n\t" )
+			       : "=r" ( flags ),
+				 "=a" ( extmem_1m_to_16m_k ),
+				 "=b" ( extmem_16m_plus_64k ),
+				 "=c" ( confmem_1m_to_16m_k ),
+				 "=d" ( confmem_16m_plus_64k )
+			       : "a" ( 0xe801 ) );
+
+	if ( flags & CF ) {
+		DBG ( "INT 15,e801 failed with CF set\n" );
+		return 0;
+	}
+
+	if ( ! ( extmem_1m_to_16m_k | extmem_16m_plus_64k ) ) {
+		DBG ( "INT 15,e801 extmem=0, using confmem\n" );
+		extmem_1m_to_16m_k = confmem_1m_to_16m_k;
+		extmem_16m_plus_64k = confmem_16m_plus_64k;
+	}
+
+	extmem = ( extmem_1m_to_16m_k + ( extmem_16m_plus_64k * 64 ) );
+	DBG ( "INT 15,e801 extended memory size %d+64*%d=%d kB "
+	      "[100000,%llx)\n", extmem_1m_to_16m_k, extmem_16m_plus_64k,
+	      extmem, ( 0x100000 + ( ( ( uint64_t ) extmem ) * 1024 ) ) );
+
+	/* Sanity check.  Some BIOSes report the entire 4GB address
+	 * space as available, which cannot be correct (since that
+	 * would leave no address space available for 32-bit PCI
+	 * BARs).
+	 */
+	if ( extmem == ( 0x400000 - 0x400 ) ) {
+		DBG ( "INT 15,e801 reported whole 4GB; assuming insane\n" );
+		return 0;
+	}
+
+	return extmem;
+}
+
+/**
+ * Get size of extended memory via INT 15,88
+ *
+ * @ret extmem		Extended memory size, in kB
+ */
+static unsigned int extmemsize_88 ( void ) {
+	uint16_t extmem;
+
+	/* Ignore CF; it is not reliable for this call */
+	__asm__ __volatile__ ( REAL_CODE ( "int $0x15" )
+			       : "=a" ( extmem ) : "a" ( 0x8800 ) );
+
+	DBG ( "INT 15,88 extended memory size %d kB [100000, %x)\n",
+	      extmem, ( 0x100000 + ( extmem * 1024 ) ) );
+	return extmem;
+}
+
+/**
+ * Get size of extended memory
+ *
+ * @ret extmem		Extended memory size, in kB
+ *
+ * Note that this is only an approximation; for an accurate picture,
+ * use the E820 memory map obtained via get_memmap();
+ */
+unsigned int extmemsize ( void ) {
+	unsigned int extmem;
+
+	/* Try INT 15,e801 first, then fall back to INT 15,88 */
+	extmem = extmemsize_e801();
+	if ( ! extmem )
+		extmem = extmemsize_88();
+	return extmem;
+}
+
+/**
+ * Get e820 memory map
+ *
+ * @v memmap		Memory map to fill in
+ * @ret rc		Return status code
+ */
+static int meme820 ( struct memory_map *memmap ) {
+	struct memory_region *region = memmap->regions;
+	uint32_t next = 0;
+	uint32_t smap;
+	size_t size;
+	unsigned int flags;
+	unsigned int discard_D;
+
+	/* Clear the E820 buffer.  Do this once before starting,
+	 * rather than on each call; some BIOSes rely on the contents
+	 * being preserved between calls.
+	 */
+	memset ( &e820buf, 0, sizeof ( e820buf ) );
+
+	do {
+		/* Some BIOSes corrupt %esi for fun. Guard against
+		 * this by telling gcc that all non-output registers
+		 * may be corrupted.
+		 */
+		__asm__ __volatile__ ( REAL_CODE ( "pushl %%ebp\n\t"
+						   "stc\n\t"
+						   "int $0x15\n\t"
+						   "pushfw\n\t"
+						   "popw %%dx\n\t"
+						   "popl %%ebp\n\t" )
+				       : "=a" ( smap ), "=b" ( next ),
+					 "=c" ( size ), "=d" ( flags ),
+					 "=D" ( discard_D )
+				       : "a" ( 0xe820 ), "b" ( next ),
+					 "D" ( __from_data16 ( &e820buf ) ),
+					 "c" ( sizeof ( e820buf ) ),
+					 "d" ( SMAP )
+				       : "esi", "memory" );
+
+		if ( smap != SMAP ) {
+			DBG ( "INT 15,e820 failed SMAP signature check\n" );
+			return -ENOTSUP;
+		}
+
+		if ( size < E820_MIN_SIZE ) {
+			DBG ( "INT 15,e820 returned only %zd bytes\n", size );
+			return -EINVAL;
+		}
+
+		if ( flags & CF ) {
+			DBG ( "INT 15,e820 terminated on CF set\n" );
+			break;
+		}
+
+		/* If first region is not RAM, assume map is invalid */
+		if ( ( memmap->count == 0 ) &&
+		     ( e820buf.type != E820_TYPE_RAM ) ) {
+		       DBG ( "INT 15,e820 failed, first entry not RAM\n" );
+		       return -EINVAL;
+		}
+
+		DBG ( "INT 15,e820 region [%llx,%llx) type %d",
+		      e820buf.start, ( e820buf.start + e820buf.len ),
+		      ( int ) e820buf.type );
+		if ( size > offsetof ( typeof ( e820buf ), attrs ) ) {
+			DBG ( " (%s", ( ( e820buf.attrs & E820_ATTR_ENABLED )
+					? "enabled" : "disabled" ) );
+			if ( e820buf.attrs & E820_ATTR_NONVOLATILE )
+				DBG ( ", non-volatile" );
+			if ( e820buf.attrs & E820_ATTR_UNKNOWN )
+				DBG ( ", other [%08x]", e820buf.attrs );
+			DBG ( ")" );
+		}
+		DBG ( "\n" );
+
+		/* Discard non-RAM regions */
+		if ( e820buf.type != E820_TYPE_RAM )
+			continue;
+
+		/* Check extended attributes, if present */
+		if ( size > offsetof ( typeof ( e820buf ), attrs ) ) {
+			if ( ! ( e820buf.attrs & E820_ATTR_ENABLED ) )
+				continue;
+			if ( e820buf.attrs & E820_ATTR_NONVOLATILE )
+				continue;
+		}
+
+		region->start = e820buf.start;
+		region->end = e820buf.start + e820buf.len;
+		region++;
+		memmap->count++;
+
+		if ( memmap->count >= ( sizeof ( memmap->regions ) /
+					sizeof ( memmap->regions[0] ) ) ) {
+			DBG ( "INT 15,e820 too many regions returned\n" );
+			/* Not a fatal error; what we've got so far at
+			 * least represents valid regions of memory,
+			 * even if we couldn't get them all.
+			 */
+			break;
+		}
+	} while ( next != 0 );
+
+	/* Sanity checks.  Some BIOSes report complete garbage via INT
+	 * 15,e820 (especially at POST time), despite passing the
+	 * signature checks.  We currently check for a base memory
+	 * region (starting at 0) and at least one high memory region
+	 * (starting at 0x100000).
+	 */
+	if ( memmap->count < 2 ) {
+		DBG ( "INT 15,e820 returned only %d regions; assuming "
+		      "insane\n", memmap->count );
+		return -EINVAL;
+	}
+	if ( memmap->regions[0].start != 0 ) {
+		DBG ( "INT 15,e820 region 0 starts at %llx (expected 0); "
+		      "assuming insane\n", memmap->regions[0].start );
+		return -EINVAL;
+	}
+	if ( memmap->regions[1].start != 0x100000 ) {
+		DBG ( "INT 15,e820 region 1 starts at %llx (expected 100000); "
+		      "assuming insane\n", memmap->regions[0].start );
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * Get memory map
+ *
+ * @v memmap		Memory map to fill in
+ */
+void get_memmap ( struct memory_map *memmap ) {
+	unsigned int basemem, extmem;
+	int rc;
+
+	DBG ( "Fetching system memory map\n" );
+
+	/* Clear memory map */
+	memset ( memmap, 0, sizeof ( *memmap ) );
+
+	/* Get base and extended memory sizes */
+	basemem = basememsize();
+	DBG ( "FBMS base memory size %d kB [0,%x)\n",
+	      basemem, ( basemem * 1024 ) );
+	extmem = extmemsize();
+	
+	/* Try INT 15,e820 first */
+	if ( ( rc = meme820 ( memmap ) ) == 0 ) {
+		DBG ( "Obtained system memory map via INT 15,e820\n" );
+		return;
+	}
+
+	/* Fall back to constructing a map from basemem and extmem sizes */
+	DBG ( "INT 15,e820 failed; constructing map\n" );
+	memmap->regions[0].end = ( basemem * 1024 );
+	memmap->regions[1].start = 0x100000;
+	memmap->regions[1].end = 0x100000 + ( extmem * 1024 );
+	memmap->count = 2;
+}