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| author | Danny Holman <dholman@gymli.org> | 2022-01-15 16:20:52 -0600 |
|---|---|---|
| committer | Danny Holman <dholman@gymli.org> | 2022-01-15 16:22:58 -0600 |
| commit | acc73186bc3de78ceb0a54cbf2605dff1b9a6d62 (patch) | |
| tree | 0b2b930e1e9ad4f96d6b91ff7400a14f7d0335c6 /arch/i386/boot/boot.s | |
| parent | 5db084e3b478be1c9aa9caeeea94b949264aa853 (diff) | |
arch: i386: simplifiy GDT setup
Simplify the setup and definitions of GDT/TSS entries.
Signed-off-by: Danny Holman <dholman@gymli.org>
Diffstat (limited to 'arch/i386/boot/boot.s')
| -rw-r--r-- | arch/i386/boot/boot.s | 38 |
1 files changed, 33 insertions, 5 deletions
diff --git a/arch/i386/boot/boot.s b/arch/i386/boot/boot.s index c62abbf..4b32ca2 100644 --- a/arch/i386/boot/boot.s +++ b/arch/i386/boot/boot.s @@ -25,7 +25,6 @@ boot_page_table0: .section .multiboot.text, "a" .global _start .type _start, @function - _start: movl $(boot_page_table0 - 0xC0000000), %edi movl $0, %esi @@ -73,6 +72,7 @@ _start: call pic_remap call kernel_main + call jump_userspace cli 1: hlt @@ -80,11 +80,9 @@ _start: .global flush_gdt .type flush_gdt, @function - flush_gdt: cli - movl 4(%esp), %eax - lgdt (%eax) + lgdt (gp) movw $0x10, %ax movw %ax, %ds movw %ax, %es @@ -92,4 +90,34 @@ flush_gdt: movw %ax, %gs movw %ax, %ss jmp $0x08, $.flush -.flush: ret +.flush: + ret + +.global flush_tss +.type flush_tss, @function +flush_tss: + movw $0x28, %ax + ltr %ax + ret + +.global jump_userspace +.type jump_userspace, @function +jump_userspace: + cli + movw $0x23, %ax + movw %ax, %ds + movw %ax, %es + movw %ax, %fs + movw %ax, %gs + + pushl $0x23 + pushl %esp + pushf + orl $0x200, (%esp) + pushl $0x8 + pushl $test_user_function + iret + +test_user_function: + movl $1, %eax + int $0x80 |