diff mbox

[v2,2/5] s390-ccw: ipl structs for eckd cdl/ldl

Message ID 1513030760-26245-3-git-send-email-walling@linux.vnet.ibm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Collin L. Walling Dec. 11, 2017, 10:19 p.m. UTC
ECKD DASDs have different IPL structures for CDL and LDL
formats. The current Ipl1 and Ipl2 structs follow the CDL
format, so we prepend "EckdCdl" to them. Boot info for LDL
has been moved to a new struct: EckdLdlIpl1.

Also introduce structs for IPL stages 1 and 1b and for
disk geometry.

Signed-off-by: Collin L. Walling <walling@linux.vnet.ibm.com>
Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com>
---
 pc-bios/s390-ccw/bootmap.c | 24 ++++++++++----------
 pc-bios/s390-ccw/bootmap.h | 55 +++++++++++++++++++++++++++++++++-------------
 2 files changed, 53 insertions(+), 26 deletions(-)

Comments

Cornelia Huck Dec. 14, 2017, 5:41 p.m. UTC | #1
On Mon, 11 Dec 2017 17:19:17 -0500
"Collin L. Walling" <walling@linux.vnet.ibm.com> wrote:

> ECKD DASDs have different IPL structures for CDL and LDL
> formats. The current Ipl1 and Ipl2 structs follow the CDL
> format, so we prepend "EckdCdl" to them. Boot info for LDL
> has been moved to a new struct: EckdLdlIpl1.
> 
> Also introduce structs for IPL stages 1 and 1b and for
> disk geometry.
> 
> Signed-off-by: Collin L. Walling <walling@linux.vnet.ibm.com>
> Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com>
> ---
>  pc-bios/s390-ccw/bootmap.c | 24 ++++++++++----------
>  pc-bios/s390-ccw/bootmap.h | 55 +++++++++++++++++++++++++++++++++-------------
>  2 files changed, 53 insertions(+), 26 deletions(-)
> 

> +    mbr_block_nr =
> +        eckd_block_num((void *)&(ipl1->boot_info.bp.ipl.bm_ptr.eckd.bptr));

Let me nominate this as "crazy nested struct of the week".

(Just kidding, your patch certainly improves things in general :)


> +typedef struct EckdSeekarg {
> +    uint16_t pad;
> +    uint16_t cyl;
> +    uint16_t head;
> +    uint8_t sec;
> +    uint8_t pad2;
> +} __attribute__ ((packed)) EckdSeekarg;

Maybe make this EckdSeekArg?
Collin L. Walling Dec. 14, 2017, 9:29 p.m. UTC | #2
On 12/14/2017 12:41 PM, Cornelia Huck wrote:
> On Mon, 11 Dec 2017 17:19:17 -0500
> "Collin L. Walling" <walling@linux.vnet.ibm.com> wrote:
>
>> ECKD DASDs have different IPL structures for CDL and LDL
>> formats. The current Ipl1 and Ipl2 structs follow the CDL
>> format, so we prepend "EckdCdl" to them. Boot info for LDL
>> has been moved to a new struct: EckdLdlIpl1.
>>
>> Also introduce structs for IPL stages 1 and 1b and for
>> disk geometry.
>>
>> Signed-off-by: Collin L. Walling <walling@linux.vnet.ibm.com>
>> Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com>
>> ---
>>   pc-bios/s390-ccw/bootmap.c | 24 ++++++++++----------
>>   pc-bios/s390-ccw/bootmap.h | 55 +++++++++++++++++++++++++++++++++-------------
>>   2 files changed, 53 insertions(+), 26 deletions(-)
>>
>> +    mbr_block_nr =
>> +        eckd_block_num((void *)&(ipl1->boot_info.bp.ipl.bm_ptr.eckd.bptr));
> Let me nominate this as "crazy nested struct of the week".
>
> (Just kidding, your patch certainly improves things in general :)


Haha, well I am honored! (Cannot take full credit -- it was quite crazy 
before :)


>
>
>> +typedef struct EckdSeekarg {
>> +    uint16_t pad;
>> +    uint16_t cyl;
>> +    uint16_t head;
>> +    uint8_t sec;
>> +    uint8_t pad2;
>> +} __attribute__ ((packed)) EckdSeekarg;
> Maybe make this EckdSeekArg?
>


I'm pretty sure "Seekarg" is not a word, so your suggestion makes sense.
(plus it reads better imo)
Collin L. Walling Dec. 18, 2017, 10:11 p.m. UTC | #3
On 12/14/2017 12:41 PM, Cornelia Huck wrote:
> On Mon, 11 Dec 2017 17:19:17 -0500
> "Collin L. Walling" <walling@linux.vnet.ibm.com> wrote:
>
>> ECKD DASDs have different IPL structures for CDL and LDL
>> formats. The current Ipl1 and Ipl2 structs follow the CDL
>> format, so we prepend "EckdCdl" to them. Boot info for LDL
>> has been moved to a new struct: EckdLdlIpl1.
>>
>> Also introduce structs for IPL stages 1 and 1b and for
>> disk geometry.
>>
>> Signed-off-by: Collin L. Walling <walling@linux.vnet.ibm.com>
>> Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com>
>> ---
>>   pc-bios/s390-ccw/bootmap.c | 24 ++++++++++----------
>>   pc-bios/s390-ccw/bootmap.h | 55 +++++++++++++++++++++++++++++++++-------------
>>   2 files changed, 53 insertions(+), 26 deletions(-)
>>
>> +    mbr_block_nr =
>> +        eckd_block_num((void *)&(ipl1->boot_info.bp.ipl.bm_ptr.eckd.bptr));
> Let me nominate this as "crazy nested struct of the week".
>
> (Just kidding, your patch certainly improves things in general :)


FWIW: we can reduce it to just ipl1->boot_info.bp-- the way the structs 
are unioned
and the ordering of the fields make this possible.  Thoughts?


>
>
>> +typedef struct EckdSeekarg {
>> +    uint16_t pad;
>> +    uint16_t cyl;
>> +    uint16_t head;
>> +    uint8_t sec;
>> +    uint8_t pad2;
>> +} __attribute__ ((packed)) EckdSeekarg;
> Maybe make this EckdSeekArg?
>
Cornelia Huck Jan. 9, 2018, 3:12 p.m. UTC | #4
On Mon, 18 Dec 2017 17:11:52 -0500
"Collin L. Walling" <walling@linux.vnet.ibm.com> wrote:

> On 12/14/2017 12:41 PM, Cornelia Huck wrote:
> > On Mon, 11 Dec 2017 17:19:17 -0500
> > "Collin L. Walling" <walling@linux.vnet.ibm.com> wrote:
> >  
> >> ECKD DASDs have different IPL structures for CDL and LDL
> >> formats. The current Ipl1 and Ipl2 structs follow the CDL
> >> format, so we prepend "EckdCdl" to them. Boot info for LDL
> >> has been moved to a new struct: EckdLdlIpl1.
> >>
> >> Also introduce structs for IPL stages 1 and 1b and for
> >> disk geometry.
> >>
> >> Signed-off-by: Collin L. Walling <walling@linux.vnet.ibm.com>
> >> Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com>
> >> ---
> >>   pc-bios/s390-ccw/bootmap.c | 24 ++++++++++----------
> >>   pc-bios/s390-ccw/bootmap.h | 55 +++++++++++++++++++++++++++++++++-------------
> >>   2 files changed, 53 insertions(+), 26 deletions(-)
> >>
> >> +    mbr_block_nr =
> >> +        eckd_block_num((void *)&(ipl1->boot_info.bp.ipl.bm_ptr.eckd.bptr));  
> > Let me nominate this as "crazy nested struct of the week".
> >
> > (Just kidding, your patch certainly improves things in general :)  
> 
> 
> FWIW: we can reduce it to just ipl1->boot_info.bp-- the way the structs 
> are unioned
> and the ordering of the fields make this possible.  Thoughts?

Ah, missed that one. I'd prefer to be explicit here, even if it is long.
diff mbox

Patch

diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
index 6f8e30f..5546b79 100644
--- a/pc-bios/s390-ccw/bootmap.c
+++ b/pc-bios/s390-ccw/bootmap.c
@@ -221,9 +221,9 @@  static void run_eckd_boot_script(block_number_t mbr_block_nr)
 static void ipl_eckd_cdl(void)
 {
     XEckdMbr *mbr;
-    Ipl2 *ipl2 = (void *)sec;
+    EckdCdlIpl2 *ipl2 = (void *)sec;
     IplVolumeLabel *vlbl = (void *)sec;
-    block_number_t block_nr;
+    block_number_t mbr_block_nr;
 
     /* we have just read the block #0 and recognized it as "IPL1" */
     sclp_print("CDL\n");
@@ -231,7 +231,7 @@  static void ipl_eckd_cdl(void)
     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
     read_block(1, ipl2, "Cannot read IPL2 record at block 1");
 
-    mbr = &ipl2->u.x.mbr;
+    mbr = &ipl2->mbr;
     IPL_assert(magic_match(mbr, ZIPL_MAGIC), "No zIPL section in IPL2 record.");
     IPL_assert(block_size_ok(mbr->blockptr.xeckd.bptr.size),
                "Bad block size in zIPL section of IPL2 record.");
@@ -239,7 +239,7 @@  static void ipl_eckd_cdl(void)
                "Non-ECKD device type in zIPL section of IPL2 record.");
 
     /* save pointer to Boot Script */
-    block_nr = eckd_block_num((void *)&(mbr->blockptr));
+    mbr_block_nr = eckd_block_num((void *)&(mbr->blockptr));
 
     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
     read_block(2, vlbl, "Cannot read Volume Label at block 2");
@@ -249,7 +249,7 @@  static void ipl_eckd_cdl(void)
                "Invalid magic of volser block");
     print_volser(vlbl->f.volser);
 
-    run_eckd_boot_script(block_nr);
+    run_eckd_boot_script(mbr_block_nr);
     /* no return */
 }
 
@@ -280,8 +280,8 @@  static void print_eckd_ldl_msg(ECKD_IPL_mode_t mode)
 
 static void ipl_eckd_ldl(ECKD_IPL_mode_t mode)
 {
-    block_number_t block_nr;
-    BootInfo *bip = (void *)(sec + 0x70); /* BootInfo is MBR for LDL */
+    block_number_t mbr_block_nr;
+    EckdLdlIpl1 *ipl1 = (void *)sec;
 
     if (mode != ECKD_LDL_UNLABELED) {
         print_eckd_ldl_msg(mode);
@@ -292,15 +292,17 @@  static void ipl_eckd_ldl(ECKD_IPL_mode_t mode)
     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
     read_block(0, sec, "Cannot read block 0 to grab boot info.");
     if (mode == ECKD_LDL_UNLABELED) {
-        if (!magic_match(bip->magic, ZIPL_MAGIC)) {
+        if (!magic_match(ipl1->boot_info.magic, ZIPL_MAGIC)) {
             return; /* not applicable layout */
         }
         sclp_print("unlabeled LDL.\n");
     }
-    verify_boot_info(bip);
+    verify_boot_info(&ipl1->boot_info);
+
+    mbr_block_nr =
+        eckd_block_num((void *)&(ipl1->boot_info.bp.ipl.bm_ptr.eckd.bptr));
 
-    block_nr = eckd_block_num((void *)&(bip->bp.ipl.bm_ptr.eckd.bptr));
-    run_eckd_boot_script(block_nr);
+    run_eckd_boot_script(mbr_block_nr);
     /* no return */
 }
 
diff --git a/pc-bios/s390-ccw/bootmap.h b/pc-bios/s390-ccw/bootmap.h
index 4980838..b700d08 100644
--- a/pc-bios/s390-ccw/bootmap.h
+++ b/pc-bios/s390-ccw/bootmap.h
@@ -226,22 +226,47 @@  typedef struct BootInfo {          /* @ 0x70, record #0    */
     } bp;
 } __attribute__ ((packed)) BootInfo; /* see also XEckdMbr   */
 
-typedef struct Ipl1 {
-    unsigned char key[4]; /* == "IPL1" */
-    unsigned char data[24];
-} __attribute__((packed)) Ipl1;
+/*
+ * Structs for IPL
+ */
+#define STAGE2_BLK_CNT_MAX  24 /* Stage 1b can load up to 24 blocks */
 
-typedef struct Ipl2 {
-    unsigned char key[4]; /* == "IPL2" */
-    union {
-        unsigned char data[144];
-        struct {
-            unsigned char reserved1[92-4];
-            XEckdMbr mbr;
-            unsigned char reserved2[144-(92-4)-sizeof(XEckdMbr)];
-        } x;
-    } u;
-} __attribute__((packed)) Ipl2;
+typedef struct EckdCdlIpl1 {
+    uint8_t key[4]; /* == "IPL1" */
+    uint8_t data[24];
+} __attribute__((packed)) EckdCdlIpl1;
+
+typedef struct EckdSeekarg {
+    uint16_t pad;
+    uint16_t cyl;
+    uint16_t head;
+    uint8_t sec;
+    uint8_t pad2;
+} __attribute__ ((packed)) EckdSeekarg;
+
+typedef struct EckdStage1b {
+    uint8_t reserved[32 * STAGE2_BLK_CNT_MAX];
+    struct EckdSeekarg seek[STAGE2_BLK_CNT_MAX];
+    uint8_t unused[64];
+} __attribute__ ((packed)) EckdStage1b;
+
+typedef struct EckdStage1 {
+    uint8_t reserved[72];
+    struct EckdSeekarg seek[2];
+} __attribute__ ((packed)) EckdStage1;
+
+typedef struct EckdCdlIpl2 {
+    uint8_t key[4]; /* == "IPL2" */
+    struct EckdStage1 stage1;
+    XEckdMbr mbr;
+    uint8_t reserved[24];
+} __attribute__((packed)) EckdCdlIpl2;
+
+typedef struct EckdLdlIpl1 {
+    uint8_t reserved[24];
+    struct EckdStage1 stage1;
+    BootInfo boot_info; /* BootInfo is MBR for LDL */
+} __attribute__((packed)) EckdLdlIpl1;
 
 typedef struct IplVolumeLabel {
     unsigned char key[4]; /* == "VOL1" */