Enhance e820 memory map generation - include files missing from last commit.

1 files changed, 136 insertions, 0 deletions

diff --git a/src/coreboot.c b/src/coreboot.c
new file mode 100644
index 0000000..b040640
--- /dev/null
+++ b/src/coreboot.c
@@ -0,0 +1,136 @@
+// Coreboot interface support.
+//
+// Copyright (C) 2008  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include "memmap.h" // add_e820
+#include "util.h" // dprintf
+
+
+/****************************************************************
+ * Memory interface
+ ****************************************************************/
+
+struct cb_header {
+    u32 signature;
+    u32 header_bytes;
+    u32 header_checksum;
+    u32 table_bytes;
+    u32 table_checksum;
+    u32 table_entries;
+};
+
+#define CB_SIGNATURE 0x4f49424C // "LBIO"
+
+struct cb_memory_range {
+    u64 start;
+    u64 size;
+    u32 type;
+};
+
+#define CB_MEM_TABLE    16
+
+struct cb_memory {
+    u32 tag;
+    u32 size;
+    struct cb_memory_range map[0];
+};
+
+#define CB_TAG_MEMORY 0x01
+
+#define MEM_RANGE_COUNT(_rec) \
+        (((_rec)->size - sizeof(*(_rec))) / sizeof((_rec)->map[0]))
+
+static u16
+ipchksum(char *buf, int count)
+{
+    u16 *p = (u16*)buf;
+    u32 sum = 0;
+    while (count > 1) {
+        sum += *p++;
+        count -= 2;
+    }
+    if (count)
+        sum += *(u8*)p;
+    sum = (sum >> 16) + (sum & 0xffff);
+    sum += (sum >> 16);
+    return ~sum;
+}
+
+// Try to locate the coreboot header in a given address range.
+static struct cb_header *
+find_cb_header(char *addr, int len)
+{
+    char *end = addr + len;
+    for (; addr < end; addr += 16) {
+        struct cb_header *cbh = (struct cb_header *)addr;
+        if (cbh->signature != CB_SIGNATURE)
+            continue;
+        dprintf(1, "sig %p=%x\n", addr, cbh->signature);
+        if (! cbh->table_bytes)
+            continue;
+        if (ipchksum(addr, sizeof(*cbh)) != 0)
+            continue;
+        if (ipchksum(addr + sizeof(*cbh), cbh->table_bytes)
+            != cbh->table_checksum)
+            continue;
+        return cbh;
+    }
+    return NULL;
+}
+
+// Try to find the coreboot memory table in the given coreboot table.
+static struct cb_memory *
+find_cb_memory(struct cb_header *cbh)
+{
+    char *tbl = (char *)cbh + sizeof(*cbh);
+    int i;
+    for (i=0; i<cbh->table_entries; i++) {
+        struct cb_memory *cbm = (struct cb_memory *)tbl;
+        tbl += cbm->size;
+        if (cbm->tag == CB_TAG_MEMORY)
+            return cbm;
+    }
+    return NULL;
+}
+
+// Populate max ram and e820 map info by scanning for a coreboot table.
+void
+coreboot_fill_map()
+{
+    dprintf(3, "Attempting to find coreboot table\n");
+    struct cb_header *cbh = find_cb_header(0, 0x1000);
+    if (!cbh)
+        goto fail;
+    struct cb_memory *cbm = find_cb_memory(cbh);
+    if (!cbm)
+        goto fail;
+
+    u64 maxram = 0;
+    int i, count = MEM_RANGE_COUNT(cbm);
+    for (i=0; i<count; i++) {
+        struct cb_memory_range *m = &cbm->map[i];
+        u32 type = m->type;
+        if (type == CB_MEM_TABLE)
+            type = E820_RESERVED;
+        if ((type == E820_ACPI || type == E820_RAM)
+            && (m->start + m->size) > maxram)
+            maxram = m->start + m->size;
+        add_e820(m->start, m->size, type);
+    }
+
+    // Ughh - coreboot likes to set a map at 0x0000-0x1000, but this
+    // confuses grub.  So, override it.
+    add_e820(0, 16*1024, E820_RAM);
+
+    SET_EBDA(ram_size, maxram);
+    return;
+
+fail:
+    // No table found..  Use 16Megs as a dummy value.
+    dprintf(1, "Unable to find coreboot table!\n");
+    SET_EBDA(ram_size, 16*1024*1024);
+    add_e820(0, 16*1024*1024, E820_RAM);
+    return;
+}