diff options
| -rw-r--r-- | src/arch/x86/include/mode_switch.h | 70 | ||||
| -rw-r--r-- | src/cpu/x86/64bit/mode_switch.S | 70 | ||||
| -rw-r--r-- | src/cpu/x86/Makefile.inc | 3 |
3 files changed, 143 insertions, 0 deletions
diff --git a/src/arch/x86/include/mode_switch.h b/src/arch/x86/include/mode_switch.h new file mode 100644 index 0000000000..0c46da5c62 --- /dev/null +++ b/src/arch/x86/include/mode_switch.h @@ -0,0 +1,70 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include <stddef.h> +#include <stdint.h> + +#if ENV_X86_64 +int protected_mode_call_narg(uint32_t arg_count, + uint32_t func_ptr, + uint32_t opt_arg1, + uint32_t opt_arg2); + +/* + * Drops into protected mode and calls the function, which must have been compiled for x86_32. + * After the function returns it enters long mode again. + * The function pointer destination must be below 4GiB in physical memory. + * + * The called function doesn't have arguments and returns an int. + */ +static inline int protected_mode_call(void *func) +{ + return protected_mode_call_narg(0, (uintptr_t)func, 0, 0); +} + +/* + * Drops into protected mode and calls the function, which must have been compiled for x86_32. + * After the function returns it enters long mode again. + * The function pointer destination must be below 4GiB in physical memory. + * Only the lower 32bits of the argument are passed to the called function. + * + * The called function have one argument and returns an int. + */ +static inline int protected_mode_call_1arg(void *func, uint32_t arg1) +{ + return protected_mode_call_narg(1, (uintptr_t)func, arg1, 0); +} + +/* + * Drops into protected mode and calls the function, which must have been compiled for x86_32. + * After the function returns it enters long mode again. + * The function pointer destination must be below 4GiB in physical memory. + * Only the lower 32bits of the argument are passed to the called function. + * + * The called function has two arguments and returns an int. + */ +static inline int protected_mode_call_2arg(void *func, uint32_t arg1, uint32_t arg2) +{ + return protected_mode_call_narg(2, (uintptr_t)func, arg1, arg2); +} +#else +static inline int protected_mode_call(void *func) +{ + int (*doit)(void) = func; + + return doit(); +} + +static inline int protected_mode_call_1arg(void *func, uint32_t arg1) +{ + int (*doit)(uint32_t arg1) = func; + + return doit(arg1); +} + +static inline int protected_mode_call_2arg(void *func, uint32_t arg1, uint32_t arg2) +{ + int (*doit)(uint32_t arg1, uint32_t arg2) = func; + + return doit(arg1, arg2); +} +#endif diff --git a/src/cpu/x86/64bit/mode_switch.S b/src/cpu/x86/64bit/mode_switch.S new file mode 100644 index 0000000000..eea104bcf3 --- /dev/null +++ b/src/cpu/x86/64bit/mode_switch.S @@ -0,0 +1,70 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +.text +.code64 + .section ".text.protected_mode_call", "ax", @progbits + .globl protected_mode_call_narg +protected_mode_call_narg: + + push %rbp + mov %rsp, %rbp + /* Preserve registers */ + push %rbx + push %r12 + push %r13 + push %r14 + push %r15 + + /* Arguments to stack */ + push %rdi + push %rsi + push %rdx + push %rcx + + #include <cpu/x86/64bit/exit32.inc> + + movl -48(%ebp), %eax /* Argument count */ + movl -64(%ebp), %edx /* Argument 0 */ + movl -72(%ebp), %ecx /* Argument 1 */ + + /* Align the stack */ + andl $0xFFFFFFF0, %esp + test %eax, %eax + je 1f /* Zero arguments */ + + subl $1, %eax + test %eax, %eax + je 2f /* One argument */ + + /* Two arguments */ + subl $8, %esp + pushl %ecx /* Argument 1 */ + pushl %edx /* Argument 0 */ + jmp 1f +2: + subl $12, %esp + pushl %edx /* Argument 0 */ + +1: + movl -56(%ebp), %ebx /* Function to call */ + call *%ebx + movl %eax, %ebx + + /* Preserves ebx */ + #include <cpu/x86/64bit/entry64.inc> + + /* Place return value in rax */ + movl %ebx, %eax + + /* Restore registers */ + mov -40(%rbp), %r15 + mov -32(%rbp), %r14 + mov -24(%rbp), %r13 + mov -16(%rbp), %r12 + mov -8(%rbp), %rbx + + /* Restore stack pointer */ + mov %rbp, %rsp + pop %rbp + + ret diff --git a/src/cpu/x86/Makefile.inc b/src/cpu/x86/Makefile.inc index 2f789f7581..cd73b72fe3 100644 --- a/src/cpu/x86/Makefile.inc +++ b/src/cpu/x86/Makefile.inc @@ -1,4 +1,7 @@ subdirs-y += pae + +all-$(CONFIG_ARCH_ALL_STAGES_X86_64) += 64bit/mode_switch.S + subdirs-$(CONFIG_PARALLEL_MP) += name ramstage-$(CONFIG_PARALLEL_MP) += mp_init.c ramstage-y += backup_default_smm.c |