diff options
| author | Michael Brown | 2016-02-18 17:36:04 +0100 |
|---|---|---|
| committer | Michael Brown | 2016-02-18 18:12:16 +0100 |
| commit | 196f0f2551a4f82d2968c6e3a50aaa54a45ec779 (patch) | |
| tree | a253528f9e3c0851e348f7f57f0241bb3450fa4a /src/arch/x86/transitions/librm.S | |
| parent | [prefix] Standardise calls to prot_call() (diff) | |
| download | ipxe-196f0f2551a4f82d2968c6e3a50aaa54a45ec779.tar.gz ipxe-196f0f2551a4f82d2968c6e3a50aaa54a45ec779.tar.xz ipxe-196f0f2551a4f82d2968c6e3a50aaa54a45ec779.zip | |
[librm] Convert prot_call() to a real-mode near call
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/arch/x86/transitions/librm.S')
| -rw-r--r-- | src/arch/x86/transitions/librm.S | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/src/arch/x86/transitions/librm.S b/src/arch/x86/transitions/librm.S index c702c0cc..46c1ab97 100644 --- a/src/arch/x86/transitions/librm.S +++ b/src/arch/x86/transitions/librm.S @@ -132,7 +132,6 @@ init_librm: /* Initialise IDT */ pushl $init_idt - pushw %cs call prot_call /* Restore registers */ @@ -358,7 +357,7 @@ rm_gdtr: .long 0 /* Base */ /**************************************************************************** - * prot_call (real-mode far call, 16-bit real-mode far return address) + * prot_call (real-mode near call, 16-bit real-mode near return address) * * Call a specific C function in the protected-mode code. The * prototype of the C function must be @@ -384,7 +383,6 @@ rm_gdtr: * * Example usage: * pushl $pxe_api_call - * pushw %cs * call prot_call * to call in to the C function * void pxe_api_call ( struct i386_all_regs *ix86 ); @@ -394,7 +392,8 @@ rm_gdtr: PC_OFFSET_GDT: .space 6 PC_OFFSET_IDT: .space 6 PC_OFFSET_IX86: .space SIZEOF_I386_ALL_REGS -PC_OFFSET_RETADDR: .space 4 +PC_OFFSET_PADDING: .space 2 /* for alignment */ +PC_OFFSET_RETADDR: .space 2 PC_OFFSET_FUNCTION: .space 4 PC_OFFSET_END: .previous @@ -404,6 +403,7 @@ PC_OFFSET_END: .globl prot_call prot_call: /* Preserve registers, flags and GDT on external RM stack */ + pushfw /* padding */ pushfl pushal pushw %gs @@ -455,7 +455,8 @@ pc_rmode: */ addr32 movl -20(%esp), %esp popfl - lret $4 + popfw /* padding */ + ret $4 /**************************************************************************** * real_call (protected-mode near call, 32-bit virtual return address) @@ -554,7 +555,6 @@ flatten_real_mode: movb $0x8f, real_ds + 6 /* Call dummy protected-mode function */ pushl $flatten_dummy - pushw %cs call prot_call /* Restore GDT */ movb $0x00, real_cs + 6 |