diff options
| author | Alejandro Sior <aho@sior.be> | 2022-05-20 14:27:08 +0200 |
|---|---|---|
| committer | Alejandro Sior <aho@sior.be> | 2022-05-20 14:27:08 +0200 |
| commit | 68e5c0c5c9dc26e9c7ce4bf5252719ee8dc4b3ae (patch) | |
| tree | 0dac63296f1585bda3464dc58f5fad96b516b34b | |
| parent | 74d0e8c1f9527054a012aa9937c590537f9d3d5b (diff) | |
bios.call: store the gdt on 8+2 bytes
| -rw-r--r-- | main.ha | 8 | ||||
| -rw-r--r-- | rt/+x86_64/realcall.S | 11 |
2 files changed, 15 insertions, 4 deletions
@@ -20,4 +20,12 @@ export fn main() void = { bios::regs.ecx = 0; bios::regs.edx = 5 << 8 | 5; bios::call(0x10); + bios::regs.eax = 0x2 << 8; + bios::regs.ebx = 0; + bios::regs.edx = 0 << 8 | 0; + bios::call(0x10); + bios::regs.eax = 0x9 << 8 | 'A': u16; + bios::regs.ebx = 0 << 8 | 0xd; + bios::regs.ecx = 8; + bios::call(0x10); }; diff --git a/rt/+x86_64/realcall.S b/rt/+x86_64/realcall.S index ffbc0a9..1c51f99 100644 --- a/rt/+x86_64/realcall.S +++ b/rt/+x86_64/realcall.S @@ -21,6 +21,8 @@ prev_idt: .quad 0x0 prev_gdt: .quad 0x0 + .short 0x0 + # :The 64 bits sidt stores on 8+2 bytes # :real_call # This function is intended to be called from long mode @@ -55,7 +57,7 @@ bios.call: cli - sidt (prev_idt) + #sidt (prev_idt) sgdt (prev_gdt) lgdt (gdtr32) @@ -122,6 +124,7 @@ real_call_int: cli + xchg %bx, %bx mov %es, (res) mov %eax, (reax) mov %ebx, (rebx) @@ -155,14 +158,13 @@ real_call_to_pmode_up: or $1 << 31, %eax mov %eax, %cr0 - lgdt (prev_gdt) - # :At this point %ds is latest in stack pop %ax # :At this point %cs is latest in stack # Do a long jump push $real_call_to_longmode_up + lgdt (prev_gdt) retf .code64 real_call_to_longmode_up: @@ -174,7 +176,7 @@ real_call_to_longmode_up: # :Avoid doing this until the bootloader loads a 64 bits IDT # XXX - #idt (prev_idt) + # lidt (prev_idt) real_call_end: popf @@ -183,4 +185,5 @@ real_call_end: pop %r13 pop %r12 pop %rbx + cli ret |