support smbios

alloc buffer in fseg memory and fill it with smbios anchor and
tables which read from the fw_cfg, then check type0 table and
rebuild it if it's not exist.

mainly inspired by the seabios, and borrowed some code from it.

Reviewed-by: Ben Luo <luoben@linux.alibaba.com>
Signed-off-by: kaihuan.pkh <kaihuan.pkh@alibaba-inc.com>

8 files changed, 188 insertions, 10 deletions

diff --git a/Makefile b/Makefile
index adbf1b3..b5970a8 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 obj-y = code16.o entry.o main.o string.o printf.o cstart.o fw_cfg.o
 obj-y += linuxboot.o malloc.o tables.o hwsetup.o pci.o code32seg.o
-obj-y += mptable.o
+obj-y += mptable.o smbios.o
 
 all-y = bios.bin
 all: $(all-y)
diff --git a/README b/README
index 7f45a06..e04e984 100644
--- a/README
+++ b/README
@@ -44,5 +44,4 @@ Usage
 TODO
 ====
 
-* SMBIOS tables
 * Add the possibility to configure out PIC and PCI bridge initialization
diff --git a/include/smbios.h b/include/smbios.h
new file mode 100644
index 0000000..ec033ce
--- /dev/null
+++ b/include/smbios.h
@@ -0,0 +1 @@
+void extract_smbios(void);
diff --git a/include/string.h b/include/string.h
index d1bb037..cf9fde9 100644
--- a/include/string.h
+++ b/include/string.h
@@ -2,6 +2,7 @@
 #define BIOS_STRING_H
 
 #include <stddef.h>
+#include <inttypes.h>
 
 unsigned long strlen(const char *buf);
 char *strcat(char *dest, const char *src);
@@ -12,6 +13,7 @@ char *strstr(const char *s1, const char *s2);
 int memcmp(const void *s1, const void *s2, size_t n);
 void *memmove(void *dest, const void *src, size_t n);
 void *memchr(const void *s, int c, size_t n);
+uint8_t csum8(uint8_t *buf, uint32_t len);
 
 static inline void *memset(void *s, int c, size_t n)
 {
diff --git a/main.c b/main.c
index ea67f3c..afa2200 100644
--- a/main.c
+++ b/main.c
@@ -7,6 +7,7 @@
 #include "fw_cfg.h"
 #include "pci.h"
 #include "benchmark.h"
+#include "smbios.h"
 
 static void set_realmode_int(int vec, void *p)
 {
@@ -98,7 +99,7 @@ int __attribute__ ((section (".text.startup"))) main(void)
 	extract_acpi();
 	extract_e820();
 	setup_mptable();
-	// extract_smbios();
+	extract_smbios();
 	boot_from_fwcfg();
 	panic();
 }
diff --git a/smbios.c b/smbios.c
new file mode 100644
index 0000000..1ed98b6
--- /dev/null
+++ b/smbios.c
@@ -0,0 +1,174 @@
+#include <inttypes.h>
+#include "smbios.h"
+#include "string.h"
+#include "fw_cfg.h"
+
+#define VERSION "0.1"
+#define BIOS_NAME "qboot"
+#define BIOS_DATE "11/11/2019"
+
+struct smbios_entry_point {
+    uint32_t signature;
+    uint8_t checksum;
+    uint8_t length;
+    uint8_t smbios_major_version;
+    uint8_t smbios_minor_version;
+    uint16_t max_structure_size;
+    uint8_t entry_point_revision;
+    uint8_t formatted_area[5];
+    char intermediate_anchor_string[5];
+    uint8_t intermediate_checksum;
+    uint16_t structure_table_length;
+    uint32_t structure_table_address;
+    uint16_t number_of_structures;
+    uint8_t smbios_bcd_revision;
+} __attribute__((packed));
+
+struct smbios_structure_header {
+    uint8_t type;
+    uint8_t length;
+    uint16_t handle;
+} __attribute__((packed));
+
+struct smbios_type_0 {
+    struct smbios_structure_header header;
+    uint8_t vendor_str;
+    uint8_t bios_version_str;
+    uint16_t bios_starting_address_segment;
+    uint8_t bios_release_date_str;
+    uint8_t bios_rom_size;
+    uint8_t bios_characteristics[8];
+    uint8_t bios_characteristics_extension_bytes[2];
+    uint8_t system_bios_major_release;
+    uint8_t system_bios_minor_release;
+    uint8_t embedded_controller_major_release;
+    uint8_t embedded_controller_minor_release;
+} __attribute__((packed));
+
+#define set_str_field_or_skip(type, field, value)                       \
+    do {                                                                \
+        int size = (value != NULL) ? strlen(value) + 1 : 0;             \
+        if (size > 1) {                                                 \
+            memcpy(end, value, size);                                   \
+            end += size;                                                \
+            p->field = ++str_index;                                     \
+        } else {                                                        \
+            p->field = 0;                                               \
+        }                                                               \
+    } while (0)
+
+static void smbios_new_type_0(void *start, const char *vendor,
+                        const char *version, const char *date)
+{
+    struct smbios_type_0 *p = (struct smbios_type_0 *)start;
+    char *end = (char *)start + sizeof(struct smbios_type_0);
+    int str_index = 0;
+
+    p->header.type = 0;
+    p->header.length = sizeof(struct smbios_type_0);
+    p->header.handle = 0;
+
+    set_str_field_or_skip(0, vendor_str, vendor);
+    set_str_field_or_skip(0, bios_version_str, version);
+    p->bios_starting_address_segment = 0xe800;
+    set_str_field_or_skip(0, bios_release_date_str, date);
+
+    p->bios_rom_size = 0; /* FIXME */
+
+    /* BIOS characteristics not supported */
+    memset(p->bios_characteristics, 0, 8);
+    p->bios_characteristics[0] = 0x08;
+
+    /* Enable targeted content distribution (needed for SVVP) */
+    p->bios_characteristics_extension_bytes[0] = 0;
+    p->bios_characteristics_extension_bytes[1] = 4;
+
+    p->system_bios_major_release = 0;
+    p->system_bios_minor_release = 0;
+    p->embedded_controller_major_release = 0xFF;
+    p->embedded_controller_minor_release = 0xFF;
+
+    *end = 0;
+    end++;
+    if (!str_index) {
+        *end = 0;
+        end++;
+    }
+}
+
+static struct smbios_structure_header *smbios_next(struct smbios_entry_point *ep,
+                                                   struct smbios_structure_header *hdr)
+{
+    if (!ep)
+        return NULL;
+    void *start = (void *)ep->structure_table_address;
+    void *end = start + ep->structure_table_length;
+    void *ptr;
+
+    if (hdr == NULL)
+        ptr = start;
+    else {
+        ptr = hdr;
+        if (ptr + sizeof(*hdr) > end)
+            return NULL;
+        ptr += hdr->length + 2;
+        while (ptr < end &&
+               (*(uint8_t*)(ptr-1) != '\0' || *(uint8_t*)(ptr-2) != '\0'))
+            ptr++;
+    }
+    hdr = ptr;
+    if (ptr >= end || ptr + sizeof(*hdr) >= end || ptr + hdr->length >= end)
+        return NULL;
+    return hdr;
+}
+
+void extract_smbios(void)
+{
+    int id;
+    struct smbios_entry_point *ep;
+    uint8_t *qtables;
+    uint16_t qtables_length;
+    struct smbios_structure_header *table_header = NULL;
+    int need_t0 = 1;
+    uint16_t t0_len = sizeof(struct smbios_type_0) + strlen(BIOS_NAME) +
+                        strlen(VERSION) + strlen(BIOS_DATE) + 4;
+
+    id = fw_cfg_file_id("etc/smbios/smbios-anchor");
+    if (id == -1 || (sizeof(*ep) != fw_cfg_file_size(id)))
+        return ;
+    /* malloc_fseg is 16-byte alignment default */
+    if (!(ep = malloc_fseg(sizeof(*ep))))
+        return;
+    fw_cfg_read_file(id, ep, sizeof(*ep));
+
+    qtables_length = ep->structure_table_length;
+    id = fw_cfg_file_id("etc/smbios/smbios-tables");
+    if (id == -1 || qtables_length != fw_cfg_file_size(id))
+        return ;
+    if (!(qtables = malloc_fseg(qtables_length + t0_len)))
+        return ;
+    qtables += t0_len;
+    fw_cfg_read_file(id, qtables, qtables_length);
+
+    ep->structure_table_address = (uint32_t) qtables;
+    ep->structure_table_length = qtables_length;
+
+    while ((table_header = smbios_next(ep, table_header))) {
+         if (table_header->type == 0) {
+            need_t0 = 0;
+            break;
+         }
+    }
+
+    if (need_t0) {
+        smbios_new_type_0(qtables - t0_len, BIOS_NAME, VERSION, BIOS_DATE);
+        ep->number_of_structures++;
+        ep->structure_table_address -= t0_len;
+        ep->structure_table_length += t0_len;
+        if (t0_len > ep->max_structure_size)
+            ep->max_structure_size = t0_len;
+    }
+
+    ep->checksum -= csum8((void *) ep, 0x10);
+    ep->intermediate_checksum -= csum8((void *) ep + 0x10, ep->length - 0x10);
+}
diff --git a/string.c b/string.c
index 8d1cb7a..e3ebfa7 100644
--- a/string.c
+++ b/string.c
@@ -132,3 +132,11 @@ long atol(const char *ptr)
 
     return acc;
 }
+
+uint8_t csum8(uint8_t *buf, uint32_t len)
+{
+	uint32_t s = 0;
+	while (len-- > 0)
+		s += *buf++;
+	return s;
+}
diff --git a/tables.c b/tables.c
index 9493691..9934a91 100644
--- a/tables.c
+++ b/tables.c
@@ -107,13 +107,6 @@ static void do_ptr(char *dest, char *src, uint32_t offset, uint8_t size)
 	memcpy(q, &data.b, size);
 }
 
-static inline uint8_t csum8(uint8_t *buf, uint32_t len)
-{
-	uint32_t s = 0;
-	while (len-- > 0)
-		s += *buf++;
-	return s;
-}
 static void do_checksum(char *file, uint32_t offset, uint32_t start, uint32_t len)
 {
 	uint8_t *p;