Unify checksum functions.

Several checksum functions were scattered through source - use just one.
mcb30 · Mar 29, 2008 · 2e7ab8b · 2e7ab8b
1 parent 46df61c
commit 2e7ab8b
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Showing 5 changed files with 25 additions and 59 deletions.
diff --git a/src/disk.c b/src/disk.c
@@ -26,16 +26,6 @@
         disk_ret(__regs, DISK_RET_SUCCESS);     \
     } while (0)
 
-static u8
-checksum_seg(u16 seg, u16 offset, u32 len)
-{
-    u32 i;
-    u8 sum = 0;
-    for (i=0; i<len; i++)
-        sum += GET_FARVAR(seg, *(u8*)(offset+i));
-    return sum;
-}
-
 static void
 basic_access(struct bregs *regs, u8 device, u16 command)
 {
@@ -452,9 +442,9 @@ disk_1348(struct bregs *regs, u8 device)
     else
         SET_EBDA(ata.dpte.revision, 0x10);
 
-    u8 sum = checksum_seg(EBDA_SEG
-                          , offsetof(struct extended_bios_data_area_s, ata.dpte)
-                          , 15);
+    u8 *p = MAKE_FARPTR(EBDA_SEG
+                        , offsetof(struct extended_bios_data_area_s, ata.dpte));
+    u8 sum = checksum(p, 15);
     SET_EBDA(ata.dpte.checksum, ~sum);
 
     if (size < 0x42) {
@@ -498,7 +488,7 @@ disk_1348(struct bregs *regs, u8 device)
     SET_INT13DPT(regs, device_path[2], 0);
     SET_INT13DPT(regs, device_path[4], 0L);
 
-    sum = checksum_seg(regs->ds, 30, 34);
+    sum = checksum(MAKE_FARPTR(regs->ds, 30), 34);
     SET_INT13DPT(regs, checksum, ~sum);
 }
 

diff --git a/src/post.c b/src/post.c
@@ -17,16 +17,6 @@
 #define bda ((struct bios_data_area_s *)0)
 #define ebda ((struct extended_bios_data_area_s *)(EBDA_SEG<<4))
 
-static u8
-checksum(u8 *p, u32 len)
-{
-    u32 i;
-    u8 sum = 0;
-    for (i=0; i<len; i++)
-        sum += p[i];
-    return sum;
-}
-
 static void
 init_bda()
 {
@@ -258,7 +248,7 @@ fill_hdinfo(struct fdpt_s *info, u8 typecmos, u8 basecmos)
     }
     info->cylinders = cyl;
     info->heads = heads;
-    info->checksum = ~checksum((u8*)info, sizeof(*info)-1) + 1;
+    info->checksum = -checksum((u8*)info, sizeof(*info)-1);
 }
 
 static void

diff --git a/src/rombios32.c b/src/rombios32.c
@@ -634,15 +634,6 @@ static void putle32(u8 **pp, int val)
     *pp = q;
 }
 
-static int mpf_checksum(const u8 *data, int len)
-{
-    int sum, i;
-    sum = 0;
-    for(i = 0; i < len; i++)
-        sum += data[i];
-    return sum & 0xff;
-}
-
 static unsigned long align(unsigned long addr, unsigned long v)
 {
     return (addr + v - 1) & ~(v - 1);
@@ -734,7 +725,7 @@ static void mptable_init(void)
     mp_config_table[4] = len;
     mp_config_table[5] = len >> 8;
 
-    mp_config_table[7] = -mpf_checksum(mp_config_table, q - mp_config_table);
+    mp_config_table[7] = -checksum(mp_config_table, q - mp_config_table);
 
     mp_config_table_size = q - mp_config_table;
 
@@ -764,8 +755,8 @@ static void mptable_init(void)
     putb(&q, 0);
     putb(&q, 0);
     putb(&q, 0);
-    float_pointer_struct[10] =
-        -mpf_checksum(float_pointer_struct, q - float_pointer_struct);
+    float_pointer_struct[10] = -checksum(float_pointer_struct
+                                         , q - float_pointer_struct);
 #ifdef BX_USE_EBDA_TABLES
     ebda_cur_addr += (q - float_pointer_struct);
 #else
@@ -981,15 +972,6 @@ static inline u32 cpu_to_le32(u32 x)
     return x;
 }
 
-static int acpi_checksum(const u8 *data, int len)
-{
-    int sum, i;
-    sum = 0;
-    for(i = 0; i < len; i++)
-        sum += data[i];
-    return (-sum) & 0xff;
-}
-
 static void acpi_build_table_header(struct acpi_table_header *h,
                                     char *sig, int len, u8 rev)
 {
@@ -1011,7 +993,7 @@ static void acpi_build_table_header(struct acpi_table_header *h,
     memcpy(h->asl_compiler_id, "BXPC", 4);
 #endif
     h->asl_compiler_revision = cpu_to_le32(1);
-    h->checksum = acpi_checksum((void *)h, len);
+    h->checksum = -checksum((void *)h, len);
 }
 
 int acpi_build_processor_ssdt(u8 *ssdt)
@@ -1135,7 +1117,7 @@ void acpi_bios_init(void)
     memcpy(rsdp->oem_id, "BOCHS ", 6);
 #endif
     rsdp->rsdt_physical_address = cpu_to_le32(rsdt_addr);
-    rsdp->checksum = acpi_checksum((void *)rsdp, 20);
+    rsdp->checksum = -checksum((void *)rsdp, 20);
 
     /* RSDT */
     memset(rsdt, 0, sizeof(*rsdt));
@@ -1369,8 +1351,6 @@ smbios_entry_point_init(void *start,
                         u32 structure_table_address,
                         u16 number_of_structures)
 {
-    u8 sum;
-    int i;
     struct smbios_entry_point *ep = (struct smbios_entry_point *)start;
 
     memcpy(ep->anchor_string, "_SM_", 4);
@@ -1390,16 +1370,10 @@ smbios_entry_point_init(void *start,
     ep->checksum = 0;
     ep->intermediate_checksum = 0;
 
-    sum = 0;
-    for (i = 0; i < 0x10; i++)
-        sum += ((s8 *)start)[i];
-    ep->checksum = -sum;
+    ep->checksum = -checksum(start, 0x10);
 
-    sum = 0;
-    for (i = 0x10; i < ep->length; i++)
-        sum += ((s8 *)start)[i];
-    ep->intermediate_checksum = -sum;
-    }
+    ep->intermediate_checksum = -checksum(start + 0x10, ep->length - 0x10);
+}
 
 /* Type 0 -- BIOS Information */
 #define RELEASE_DATE_STR "01/01/2007"

diff --git a/src/util.c b/src/util.c
@@ -1,5 +1,16 @@
 #include "util.h" // usleep
 
+// Sum the bytes in the specified area.
+u8
+checksum(u8 *far_data, u32 len)
+{
+    u32 i;
+    u8 sum = 0;
+    for (i=0; i<len; i++)
+        sum += GET_FARPTR(far_data[i]);
+    return sum;
+}
+
 // Sleep for n microseconds. currently using the
 // refresh request port 0x61 bit4, toggling every 15usec
 void

diff --git a/src/util.h b/src/util.h
@@ -173,6 +173,7 @@ void VISIBLE16 handle_1553(struct bregs *regs);
 void handle_1ab1(struct bregs *regs);
 
 // util.c
+u8 checksum(u8 *far_data, u32 len);
 void usleep(u32 count);
 
 // rombios32.c