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smm: Make local variables relative to ebp

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This reduces the cognitive overhead of referencing locals via esp since
it changes with every push.

BUG=b:80539294
TEST=built and booted on grunt.

Change-Id: Ib7eb98ce3483d4fc803696c1b2496d8384317536
Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Reviewed-on: https://review.coreboot.org/27225
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>
This commit is contained in:
Raul E Rangel
2018-06-25 14:22:27 -06:00
committed by Martin Roth
parent dd549e1175
commit 0140541f50
1 changed files with 12 additions and 11 deletions
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23
src/cpu/x86/smm/smm_stub.S
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@ -131,10 +131,14 @@ smm_trampoline32:
jmp 2f jmp 2f
1: 1:
movl stack_size, %eax movl stack_size, %eax
mul %ecx mul %ecx /* %eax(stack_size) * %ecx(cpu) = %eax(offset) */
movl stack_top, %edx movl stack_top, %edx
subl %eax, %edx subl %eax, %edx /* global_stack_top - offset = stack_top */
mov %edx, %esp mov %edx, %esp
mov %esp, %ebp
/* Allocate locals (fxsave) */
subl $0x4, %esp
/* calculate fxsave location */ /* calculate fxsave location */
mov fxsave_area, %edi mov fxsave_area, %edi
@ -146,8 +150,7 @@ smm_trampoline32:
2: 2:
/* Save location of fxsave area. */ /* Save location of fxsave area. */
push %edi mov %edi, -4(%ebp)
mov %esp, %ebp
test %edi, %edi test %edi, %edi
jz 1f jz 1f
@ -165,20 +168,18 @@ smm_trampoline32:
/* Call into the c-based SMM relocation function with the platform /* Call into the c-based SMM relocation function with the platform
* parameters. Equivalent to: * parameters. Equivalent to:
* struct arg = { c_handler_params, cpu_num, smm_runtime {; * struct arg = { c_handler_params, cpu_num, smm_runtime };
* c_handler(&arg) * c_handler(&arg)
*/ */
push $(smm_runtime) push $(smm_runtime)
push %ecx push %ecx /* int cpu */
push c_handler_arg push c_handler_arg /* void *arg */
push %esp push %esp /* smm_module_params *arg (allocated on stack). */
mov c_handler, %eax mov c_handler, %eax
call *%eax call *%eax
/* Restore stack from call frame */
mov %ebp, %esp
/* Retrieve fxsave location. */ /* Retrieve fxsave location. */
pop %edi mov -4(%ebp), %edi
test %edi, %edi test %edi, %edi
jz 1f jz 1f