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Better support different kernel hand-offs. When loaded directly

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from U-Boot, the kernel is passed a standard argc/argv pair.
The Juniper loader passes the metadata pointer as the second
argument and passes 0 in the first. The FreeBSD loader passes
the metadata pointer in the first argument.

As such, have locore preserve the first 2 arguments in registers
r30 & r31. Change e500_init() to accept these arguments. Don't
pass global offsets (i.e. kernel_text and _end) as arguments to
e500_init(). We can reference those directly.

Rename e500_init() to booke_init() now that we're changing the
prototype.

In booke_init(), "decode" arg1 and arg2 to obtain the metadata
pointer correctly. For the U-Boot case, clear SBSS and BSS and
bank on having a static FDT for now. This allows loading the
ELF kernel and jumping to the entry point without trampoline.
This commit is contained in:
Marcel Moolenaar 2011-05-28 04:10:44 +00:00
parent 37bb75f740
commit ebf84ceca7
3 changed files with 62 additions and 53 deletions
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60
sys/powerpc/booke/locore.S
View File

@ -83,17 +83,18 @@ __start:
* locore registers use:
* r1 : stack pointer
* r2 : trace pointer (AP only, for early diagnostics)
* r3-r27 : scratch registers
* r28 : kernload
* r29 : temp TLB1 entry
* r30 : initial TLB1 entry we started in
* r31 : metadata pointer
* r3-r26 : scratch registers
* r27 : kernload
* r28 : temp TLB1 entry
* r29 : initial TLB1 entry we started in
* r30-r31 : arguments (metadata pointer)
*/
/*
* Keep metadata ptr in r31 for later use.
* Keep arguments in r30 & r31 for later use.
*/
mr %r31, %r3
mr %r30, %r3
mr %r31, %r4
/*
* Initial cleanup
@ -120,7 +121,7 @@ __start:
*/
bl 1f
1: mflr %r3
bl tlb1_find_current /* the entry number found is returned in r30 */
bl tlb1_find_current /* the entry found is returned in r29 */
bl tlb1_inval_all_but_current
/*
@ -140,7 +141,7 @@ __start:
/*
* Invalidate initial entry
*/
mr %r3, %r30
mr %r3, %r29
bl tlb1_inval_entry
/*
@ -170,7 +171,7 @@ __start:
bl 3f
3: mflr %r4 /* Use current address */
rlwinm %r4, %r4, 0, 0, 7 /* 16MB alignment mask */
mr %r28, %r4 /* Keep kernel load address */
mr %r27, %r4 /* Keep kernel load address */
ori %r4, %r4, (MAS3_SX | MAS3_SW | MAS3_SR)@l
mtspr SPR_MAS3, %r4 /* Set RPN and protection */
isync
@ -193,7 +194,7 @@ __start:
/*
* Invalidate temp mapping
*/
mr %r3, %r29
mr %r3, %r28
bl tlb1_inval_entry
/*
@ -201,7 +202,7 @@ __start:
*/
lis %r3, kernload@ha
addi %r3, %r3, kernload@l
stw %r28, 0(%r3)
stw %r27, 0(%r3)
#ifdef SMP
/*
* APs need a separate copy of kernload info within the __boot_page
@ -210,7 +211,7 @@ __start:
*/
lis %r3, kernload_ap@ha
addi %r3, %r3, kernload_ap@l
stw %r28, 0(%r3)
stw %r27, 0(%r3)
msync
#endif
@ -229,14 +230,11 @@ __start:
/*
* Set up arguments and jump to system initialization code
*/
lis %r3, kernel_text@ha
addi %r3, %r3, kernel_text@l
lis %r4, _end@ha
addi %r4, %r4, _end@l
mr %r5, %r31 /* metadata ptr */
mr %r3, %r30
mr %r4, %r31
/* Prepare e500 core */
bl e500_init
bl booke_init
/* Switch to thread0.td_kstack now */
mr %r1, %r3
@ -290,7 +288,7 @@ kernload_ap:
*/
bl 2f
2: mflr %r3
bl tlb1_find_current /* the entry number found is in r30 */
bl tlb1_find_current /* the entry number found is in r29 */
bl tlb1_inval_all_but_current
/*
@ -310,7 +308,7 @@ kernload_ap:
/*
* Invalidate initial entry
*/
mr %r3, %r30
mr %r3, %r29
bl tlb1_inval_entry
/*
@ -373,7 +371,7 @@ kernload_ap:
/*
* Invalidate temp mapping
*/
mr %r3, %r29
mr %r3, %r28
bl tlb1_inval_entry
/*
@ -425,7 +423,7 @@ tlb_inval_all:
blr
/*
* expects address to look up in r3, returns entry number in r30
* expects address to look up in r3, returns entry number in r29
*
* FIXME: the hidden assumption is we are now running in AS=0, but we should
* retrieve actual AS from MSR[IS|DS] and put it in MAS6[SAS]
@ -437,7 +435,7 @@ tlb1_find_current:
isync
tlbsx 0, %r3
mfspr %r17, SPR_MAS0
rlwinm %r30, %r17, 16, 20, 31 /* MAS0[ESEL] -> r30 */
rlwinm %r29, %r17, 16, 20, 31 /* MAS0[ESEL] -> r29 */
/* Make sure we have IPROT set on the entry */
mfspr %r17, SPR_MAS1
@ -470,14 +468,14 @@ tlb1_inval_entry:
blr
/*
* r30 current entry number
* r29 returned temp entry
* r29 current entry number
* r28 returned temp entry
* r3-r5 scratched
*/
tlb1_temp_mapping_as1:
/* Read our current translation */
lis %r3, MAS0_TLBSEL1@h /* Select TLB1 */
rlwimi %r3, %r30, 16, 12, 15 /* Select our current entry */
rlwimi %r3, %r29, 16, 12, 15 /* Select our current entry */
mtspr SPR_MAS0, %r3
isync
tlbre
@ -489,8 +487,8 @@ tlb1_temp_mapping_as1:
* entry is the last in TLB1
*/
lis %r3, MAS0_TLBSEL1@h /* Select TLB1 */
addi %r29, %r30, 1 /* Use next entry. */
rlwimi %r3, %r29, 16, 12, 15 /* Select temp entry */
addi %r28, %r29, 1 /* Use next entry. */
rlwimi %r3, %r28, 16, 12, 15 /* Select temp entry */
mtspr SPR_MAS0, %r3
isync
mfspr %r5, SPR_MAS1
@ -510,7 +508,7 @@ tlb1_temp_mapping_as1:
* Loops over TLB1, invalidates all entries skipping the one which currently
* maps this code.
*
* r30 current entry
* r29 current entry
* r3-r5 scratched
*/
tlb1_inval_all_but_current:
@ -524,7 +522,7 @@ tlb1_inval_all_but_current:
isync
tlbre
mfspr %r5, SPR_MAS1
cmpw %r4, %r30 /* our current entry? */
cmpw %r4, %r29 /* our current entry? */
beq 2f
rlwinm %r5, %r5, 0, 2, 31 /* clear VALID and IPROT bits */
mtspr SPR_MAS1, %r5

53
sys/powerpc/booke/machdep.c
View File

@ -190,7 +190,7 @@ SYSINIT(cpu, SI_SUB_CPU, SI_ORDER_FIRST, cpu_e500_startup, NULL);
void print_kernel_section_addr(void);
void print_kenv(void);
u_int e500_init(u_int32_t, u_int32_t, void *);
u_int booke_init(uint32_t, uint32_t);
static void
cpu_e500_startup(void *dummy)
@ -276,18 +276,40 @@ print_kernel_section_addr(void)
}
u_int
e500_init(u_int32_t startkernel, u_int32_t endkernel, void *mdp)
booke_init(uint32_t arg1, uint32_t arg2)
{
struct pcpu *pc;
void *kmdp;
void *kmdp, *mdp;
vm_offset_t dtbp, end;
uint32_t csr;
kmdp = NULL;
end = endkernel;
end = (uintptr_t)_end;
dtbp = (vm_offset_t)NULL;
/*
* Handle the various ways we can get loaded and started:
* - FreeBSD's loader passes the pointer to the metadata
* in arg1, with arg2 undefined. arg1 has a value that's
* relative to the kernel's link address (i.e. larger
* than 0xc0000000).
* - Juniper's loader passes the metadata pointer in arg2
* and sets arg1 to zero. This is to signal that the
* loader maps the kernel and starts it at its link
* address (unlike the FreeBSD loader).
* - U-Boot passes the standard argc and argv parameters
* in arg1 and arg2 (resp). arg1 is between 1 and some
* relatively small number, such as 64K. arg2 is the
* physical address of the argv vector.
*/
if (arg1 > (uintptr_t)kernel_text) /* FreeBSD loader */
mdp = (void *)arg1;
else if (arg1 == 0) /* Juniper loader */
mdp = (void *)arg2;
else /* U-Boot */
mdp = NULL;
/*
* Parse metadata and fetch parameters.
*/
@ -309,17 +331,8 @@ e500_init(u_int32_t startkernel, u_int32_t endkernel, void *mdp)
#endif
}
} else {
/*
* We should scream but how? Cannot even output anything...
*/
/*
* FIXME add return value and handle in the locore so we can
* return to the loader maybe? (this seems not very easy to
* restore everything as the TLB have all been reprogrammed
* in the locore etc...)
*/
while (1);
bzero(__sbss_start, __sbss_end - __sbss_start);
bzero(__bss_start, _end - __bss_start);
}
#if defined(FDT_DTB_STATIC)
@ -368,9 +381,7 @@ e500_init(u_int32_t startkernel, u_int32_t endkernel, void *mdp)
cninit();
/* Print out some debug info... */
debugf("e500_init: console initialized\n");
debugf(" arg1 startkernel = 0x%08x\n", startkernel);
debugf(" arg2 endkernel = 0x%08x\n", endkernel);
debugf("%s: console initialized\n", __func__);
debugf(" arg3 mdp = 0x%08x\n", (u_int32_t)mdp);
debugf(" end = 0x%08x\n", (u_int32_t)end);
debugf(" boothowto = 0x%08x\n", boothowto);
@ -403,7 +414,7 @@ e500_init(u_int32_t startkernel, u_int32_t endkernel, void *mdp)
/* Initialise virtual memory. */
pmap_mmu_install(MMU_TYPE_BOOKE, 0);
pmap_bootstrap(startkernel, end);
pmap_bootstrap((uintptr_t)kernel_text, end);
debugf("MSR = 0x%08x\n", mfmsr());
//tlb1_print_entries();
//tlb1_print_tlbentries();
@ -449,8 +460,8 @@ e500_init(u_int32_t startkernel, u_int32_t endkernel, void *mdp)
printf("L1 I-cache %sabled\n",
(csr & L1CSR1_ICE) ? "en" : "dis");
debugf("e500_init: SP = 0x%08x\n", ((uintptr_t)thread0.td_pcb - 16) & ~15);
debugf("e500_init: e\n");
debugf("%s: SP = 0x%08x\n", __func__,
((uintptr_t)thread0.td_pcb - 16) & ~15);
return (((uintptr_t)thread0.td_pcb - 16) & ~15);
}

2
sys/powerpc/booke/pmap.c
View File

@ -943,7 +943,7 @@ pte_find(mmu_t mmu, pmap_t pmap, vm_offset_t va)
/**************************************************************************/
/*
* This is called during e500_init, before the system is really initialized.
* This is called during booke_init, before the system is really initialized.
*/
static void
mmu_booke_bootstrap(mmu_t mmu, vm_offset_t start, vm_offset_t kernelend)