Stefan Reinauer (stefan.reinauer@coreboot.org) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/2789
-gerrit
commit 38ac7d464a2b75c7a5c0e7ca7cb783d0fe3ee5fa Author: Aaron Durbin adurbin@chromium.org Date: Fri Feb 8 16:56:51 2013 -0600
ramstage: prepare for relocation
The current ramstage code contains uses of symbols that cause issues when the ramstage is relocatable. There are 2 scenarios resolved by this patch:
1. Absolute symbols that are actually sizes/limits. The symbols are problematic when relocating a program because there is no way to distinguish a symbol that shouldn't be relocated and one that can. The only way to handle these symbols is to write a program to post process the relocations and keep a whitelist of ones that shouldn't be relocated. I don't believe that is a route that should be taken so fix the users of these sizes/limits encoded as absolute symbols to calculate the size at runtime or dereference a variable in memory containing the size/limit.
2. Absoulte symbols that were relocated to a fixed address. These absolute symbols are generated by assembly files to be placed at a fixed location. Again, these symbols are problematic because one can't distinguish a symbol that can't be relocated. The symbols are again resolved at runtime to allow for proper relocation.
For the symbols defining a size either use 2 symbols and calculate the difference or provide a variable in memory containing the size.
Change-Id: I1ef2bfe6fd531308218bcaac5dcccabf8edf932c Signed-off-by: Aaron Durbin adurbin@chromium.org --- src/arch/x86/boot/acpi.c | 5 +++-- src/arch/x86/boot/wakeup.S | 3 ++- src/arch/x86/lib/c_start.S | 5 ++--- src/cpu/intel/haswell/mp_init.c | 4 ++-- src/cpu/x86/lapic/lapic_cpu_init.c | 18 +++++++++++++++ src/cpu/x86/lapic/secondary.S | 8 ++++--- src/device/oprom/realmode/x86.c | 45 ++++++++++++++++++++++++++----------- src/device/oprom/realmode/x86.h | 8 +++---- src/device/oprom/realmode/x86_asm.S | 15 +++++++------ 9 files changed, 76 insertions(+), 35 deletions(-)
diff --git a/src/arch/x86/boot/acpi.c b/src/arch/x86/boot/acpi.c index fc862f4..327d175 100644 --- a/src/arch/x86/boot/acpi.c +++ b/src/arch/x86/boot/acpi.c @@ -754,7 +754,8 @@ extern int lowmem_backup_size; void (*acpi_do_wakeup)(u32 vector, u32 backup_source, u32 backup_target, u32 backup_size) asmlinkage = (void *)WAKEUP_BASE;
-extern unsigned char __wakeup, __wakeup_size; +extern unsigned char __wakeup; +extern unsigned int __wakeup_size;
void acpi_jump_to_wakeup(void *vector) { @@ -776,7 +777,7 @@ void acpi_jump_to_wakeup(void *vector) #endif
/* Copy wakeup trampoline in place. */ - memcpy((void *)WAKEUP_BASE, &__wakeup, (size_t)&__wakeup_size); + memcpy((void *)WAKEUP_BASE, &__wakeup, __wakeup_size);
#if CONFIG_COLLECT_TIMESTAMPS timestamp_add_now(TS_ACPI_WAKE_JUMP); diff --git a/src/arch/x86/boot/wakeup.S b/src/arch/x86/boot/wakeup.S index d34c583..8748aa6 100644 --- a/src/arch/x86/boot/wakeup.S +++ b/src/arch/x86/boot/wakeup.S @@ -90,5 +90,6 @@ __wakeup_segment = RELOCATED(.) .word 0x0000
.globl __wakeup_size -__wakeup_size = ( . - __wakeup) +__wakeup_size: + .long . - __wakeup
diff --git a/src/arch/x86/lib/c_start.S b/src/arch/x86/lib/c_start.S index 295283b..66af8ea 100644 --- a/src/arch/x86/lib/c_start.S +++ b/src/arch/x86/lib/c_start.S @@ -261,11 +261,10 @@ gdb_stub_breakpoint:
#endif
- .globl gdt, gdt_end, gdt_limit, idtarg + .globl gdt, gdt_end, idtarg
-gdt_limit = gdt_end - gdt - 1 /* compute the table limit */ gdtaddr: - .word gdt_limit + .word gdt_end - gdt - 1 .long gdt /* we know the offset */
.data diff --git a/src/cpu/intel/haswell/mp_init.c b/src/cpu/intel/haswell/mp_init.c index 3076d07..47683fb 100644 --- a/src/cpu/intel/haswell/mp_init.c +++ b/src/cpu/intel/haswell/mp_init.c @@ -66,7 +66,7 @@ struct saved_msr { extern char _binary_sipi_vector_start[]; /* These symbols are defined in c_start.S. */ extern char gdt[]; -extern char gdt_limit[]; +extern char gdt_end[]; extern char idtarg[];
/* This table keeps track of each CPU's APIC id. */ @@ -189,7 +189,7 @@ static void setup_default_sipi_vector_params(struct sipi_params *sp) int i;
sp->gdt = (u32)&gdt; - sp->gdtlimit = (u32)&gdt_limit; + sp->gdtlimit = (u32)&gdt_end - (u32)&gdt - 1; sp->idt_ptr = (u32)&idtarg; sp->stack_size = CONFIG_STACK_SIZE; sp->stack_top = (u32)&_estack; diff --git a/src/cpu/x86/lapic/lapic_cpu_init.c b/src/cpu/x86/lapic/lapic_cpu_init.c index 9a00b82..69430d5 100644 --- a/src/cpu/x86/lapic/lapic_cpu_init.c +++ b/src/cpu/x86/lapic/lapic_cpu_init.c @@ -52,12 +52,30 @@ int lowmem_backup_size; #endif
extern char _secondary_start[]; +extern char _secondary_gdt_addr[]; +extern char gdt[]; +extern char gdt_end[]; + +static inline void setup_secondary_gdt(void) +{ + u16 *gdt_limit; + u32 *gdt_base; + + gdt_limit = (void *)&_secondary_gdt_addr; + gdt_base = (void *)&gdt_limit[1]; + + *gdt_limit = (u32)&gdt_end - (u32)&gdt - 1; + *gdt_base = (u32)&gdt; +}
static void copy_secondary_start_to_lowest_1M(void) { extern char _secondary_start_end[]; unsigned long code_size;
+ /* Fill in secondary_start's local gdt. */ + setup_secondary_gdt(); + code_size = (unsigned long)_secondary_start_end - (unsigned long)_secondary_start;
#if CONFIG_HAVE_ACPI_RESUME diff --git a/src/cpu/x86/lapic/secondary.S b/src/cpu/x86/lapic/secondary.S index 2e0620e..6edcd0a 100644 --- a/src/cpu/x86/lapic/secondary.S +++ b/src/cpu/x86/lapic/secondary.S @@ -3,7 +3,7 @@
#if CONFIG_SMP && CONFIG_MAX_CPUS > 1 .text - .globl _secondary_start, _secondary_start_end + .globl _secondary_start, _secondary_start_end, _secondary_gdt_addr .balign 4096 _secondary_start: .code16 @@ -28,9 +28,11 @@ _secondary_start:
ljmpl $0x10, $__ap_protected_start
+ /* This will get filled in by C code. */ +_secondary_gdt_addr: gdtaddr: - .word gdt_limit /* the table limit */ - .long gdt /* we know the offset */ + .word 0 /* the table limit */ + .long 0 /* we know the offset */
_secondary_start_end:
diff --git a/src/device/oprom/realmode/x86.c b/src/device/oprom/realmode/x86.c index 5fd11b5..94b65e1 100644 --- a/src/device/oprom/realmode/x86.c +++ b/src/device/oprom/realmode/x86.c @@ -36,16 +36,37 @@ #include <boot/coreboot_tables.h> #include <device/pci_ids.h>
+/* The following symbols cannot be used directly. They need to be fixed up + * to point to the correct address location after the code has been copied + * to REALMODE_BASE. Absolute symbols are not used because those symbols are + * relocated when a relocatable ramstage is enabled. + */ +extern unsigned char __realmode_call, __realmode_interrupt; +extern unsigned char __realmode_buffer; + +#define PTR_TO_REAL_MODE(sym)\ + (void *)(REALMODE_BASE + ((char *)&(sym) - (char *)&__realmode_code)) + /* to have a common register file for interrupt handlers */ X86EMU_sysEnv _X86EMU_env;
void (*realmode_call)(u32 addr, u32 eax, u32 ebx, u32 ecx, u32 edx, - u32 esi, u32 edi) asmlinkage = - (void *)&__realmode_call; + u32 esi, u32 edi) asmlinkage;
void (*realmode_interrupt)(u32 intno, u32 eax, u32 ebx, u32 ecx, u32 edx, - u32 esi, u32 edi) asmlinkage = - (void *)&__realmode_interrupt; + u32 esi, u32 edi) asmlinkage; + +static void setup_realmode_code(void) +{ + memcpy(REALMODE_BASE, &__realmode_code, __realmode_code_size); + + /* Ensure the global pointers are relocated properly. */ + realmode_call = PTR_TO_REAL_MODE(__realmode_call); + realmode_interrupt = PTR_TO_REAL_MODE(__realmode_interrupt); + + printk(BIOS_SPEW, "Real mode stub @%p: %d bytes\n", REALMODE_BASE, + __realmode_code_size); +}
static void setup_rombios(void) { @@ -149,7 +170,7 @@ static void write_idt_stub(void *target, u8 intnum) { unsigned char *codeptr; codeptr = (unsigned char *) target; - memcpy(codeptr, &__idt_handler, (size_t)&__idt_handler_size); + memcpy(codeptr, &__idt_handler, __idt_handler_size); codeptr[3] = intnum; /* modify int# in the code stub. */ }
@@ -163,7 +184,7 @@ static void setup_realmode_idt(void) */ for (i = 0; i < 256; i++) { idts[i].cs = 0; - idts[i].offset = 0x1000 + (i * (u32)&__idt_handler_size); + idts[i].offset = 0x1000 + (i * __idt_handler_size); write_idt_stub((void *)((u32 )idts[i].offset), i); }
@@ -204,7 +225,7 @@ static u8 vbe_get_mode_info(vbe_mode_info_t * mi) { printk(BIOS_DEBUG, "VBE: Getting information about VESA mode %04x\n", mi->video_mode); - char *buffer = (char *)&__buffer; + char *buffer = PTR_TO_REAL_MODE(__realmode_buffer); u16 buffer_seg = (((unsigned long)buffer) >> 4) & 0xff00; u16 buffer_adr = ((unsigned long)buffer) & 0xffff; realmode_interrupt(0x10, VESA_GET_MODE_INFO, 0x0000, @@ -312,9 +333,8 @@ void run_bios(struct device *dev, unsigned long addr) /* Set up real-mode IDT */ setup_realmode_idt();
- memcpy(REALMODE_BASE, &__realmode_code, (size_t)&__realmode_code_size); - printk(BIOS_SPEW, "Real mode stub @%p: %d bytes\n", REALMODE_BASE, - (u32)&__realmode_code_size); + /* Make sure the code is placed. */ + setup_realmode_code();
printk(BIOS_DEBUG, "Calling Option ROM...\n"); /* TODO ES:DI Pointer to System BIOS PnP Installation Check Structure */ @@ -366,9 +386,8 @@ void do_vsmbios(void) /* Setting up realmode IDT */ setup_realmode_idt();
- memcpy(REALMODE_BASE, &__realmode_code, (size_t)&__realmode_code_size); - printk(BIOS_SPEW, "VSA: Real mode stub @%p: %d bytes\n", REALMODE_BASE, - (u32)&__realmode_code_size); + /* Make sure the code is placed. */ + setup_realmode_code();
if ((unsigned int)cbfs_load_stage(CBFS_DEFAULT_MEDIA, "vsa") != VSA2_ENTRY_POINT) { diff --git a/src/device/oprom/realmode/x86.h b/src/device/oprom/realmode/x86.h index 76d3e46..a811a56 100644 --- a/src/device/oprom/realmode/x86.h +++ b/src/device/oprom/realmode/x86.h @@ -32,10 +32,10 @@ struct realmode_idt { void x86_exception(struct eregs *info);
/* From x86_asm.S */ -extern unsigned char __idt_handler, __idt_handler_size; -extern unsigned char __realmode_code, __realmode_code_size; -extern unsigned char __realmode_call, __realmode_interrupt; -extern unsigned char __buffer; +extern unsigned char __idt_handler; +extern unsigned int __idt_handler_size; +extern unsigned char __realmode_code; +extern unsigned int __realmode_code_size;
extern void (*realmode_call)(u32 addr, u32 eax, u32 ebx, u32 ecx, u32 edx, u32 esi, u32 edi) asmlinkage; diff --git a/src/device/oprom/realmode/x86_asm.S b/src/device/oprom/realmode/x86_asm.S index 56ebb3a..54cf374 100644 --- a/src/device/oprom/realmode/x86_asm.S +++ b/src/device/oprom/realmode/x86_asm.S @@ -36,7 +36,8 @@ __idt_handler: movb $0, %al /* This instruction gets modified */ ljmp $0, $__interrupt_handler_16bit .globl __idt_handler_size -__idt_handler_size = ( . - __idt_handler) +__idt_handler_size: + .long . - __idt_handler
/* In order to be independent of coreboot's position in RAM @@ -47,7 +48,6 @@ __idt_handler_size = ( . - __idt_handler) __realmode_code:
/* Realmode IDT pointer structure. */ - .globl __realmode_idt __realmode_idt = RELOCATED(.) .word 1023 /* 16 bit limit */ .long 0 /* 24 bit base */ @@ -67,13 +67,13 @@ __registers = RELOCATED(.) .long 0 /* 20 - EDI */
/* 256 byte buffer, used by int10 */ - .globl __buffer -__buffer = RELOCATED(.) + .globl __realmode_buffer +__realmode_buffer: .skip 256
.code32 .globl __realmode_call -__realmode_call = RELOCATED(.) +__realmode_call: /* save all registers to the stack */ pusha pushf @@ -204,7 +204,7 @@ __lcall_instr = RELOCATED(.) ret
.globl __realmode_interrupt -__realmode_interrupt = RELOCATED(.) +__realmode_interrupt: /* save all registers to the stack */ pusha pushf @@ -408,6 +408,7 @@ __interrupt_handler_16bit = RELOCATED(.) iret
.globl __realmode_code_size -__realmode_code_size = (. - __realmode_code) +__realmode_code_size: + .long . - __realmode_code
.code32