Signed-off-by: Kevin O'Connor <kevin@koconnor.net> --- src/romlayout.S | 53 +++++++++++++++++++++++++++++------------------------ 1 file changed, 29 insertions(+), 24 deletions(-) diff --git a/src/romlayout.S b/src/romlayout.S index 37a0264..2a5ddff 100644 --- a/src/romlayout.S +++ b/src/romlayout.S @@ -14,7 +14,7 @@ /**************************************************************** - * Call trampolines + * 16bit / 32bit call trampolines ****************************************************************/ // Place CPU into 32bit mode from 16bit mode. @@ -127,9 +127,37 @@ transition16big: movl %ecx, %eax jmpl *%edx +// Call a 16bit SeaBIOS function from SeaBIOS 32bit C code. +// %ebx = calling function +// Clobbers: %ecx, %edx, flags, segment registers, idt/gdt + DECLFUNC __call16 + .global __call16big + .code32 +__call16: + movl $1f, %edx + jmp transition16 +__call16big: + movl $1f, %edx + jmp transition16big + + // Make call. + .code16gcc +1: calll *%ebx + // Return via transition32 + movl $(2f + BUILD_BIOS_ADDR), %edx + jmp transition32 + .code32 +2: retl + + +/**************************************************************** + * External calling trampolines + ****************************************************************/ + // Far call a 16bit function from 16bit mode with a specified cpu register state // %es:%eax = address of struct bregs // Clobbers: %e[bcd]x, %e[ds]i, flags + .code16gcc DECLFUNC __farcall16 __farcall16: // Save %eax, %ebp @@ -188,29 +216,6 @@ __farcall16: retl -// Call a 16bit SeaBIOS function from SeaBIOS 32bit C code. -// %ebx = calling function -// Clobbers: %ecx, %edx, flags, segment registers, idt/gdt - DECLFUNC __call16 - .global __call16big - .code32 -__call16: - movl $1f, %edx - jmp transition16 -__call16big: - movl $1f, %edx - jmp transition16big - - // Make call. - .code16gcc -1: calll *%ebx - // Return via transition32 - movl $(2f + BUILD_BIOS_ADDR), %edx - jmp transition32 - .code32 -2: retl - - .code16gcc // IRQ trampolines .macro IRQ_TRAMPOLINE num DECLFUNC irq_trampoline_0x\num -- 1.8.3.1