[PATCH 6/8] i386/shared/realmode_int: real mode interrupt interface
Joel Sherrill
joel.sherrill at oarcorp.com
Thu Nov 20 14:59:03 UTC 2014
On 11/20/2014 8:00 AM, Jan Dolezal wrote:
> ---
> c/src/lib/libbsp/i386/pc386/Makefile.am | 2 +
> c/src/lib/libbsp/i386/pc386/preinstall.am | 4 +
> .../libbsp/i386/shared/realmode_int/realmode_int.c | 406 +++++++++++++++++++++
> .../libbsp/i386/shared/realmode_int/realmode_int.h | 85 +++++
> 4 files changed, 497 insertions(+)
> create mode 100644 c/src/lib/libbsp/i386/shared/realmode_int/realmode_int.c
> create mode 100644 c/src/lib/libbsp/i386/shared/realmode_int/realmode_int.h
>
> diff --git a/c/src/lib/libbsp/i386/pc386/Makefile.am b/c/src/lib/libbsp/i386/pc386/Makefile.am
> index 23a46da..8c06129 100644
> --- a/c/src/lib/libbsp/i386/pc386/Makefile.am
> +++ b/c/src/lib/libbsp/i386/pc386/Makefile.am
> @@ -28,6 +28,7 @@ SUBDIRS = . tools
> include_bsp_HEADERS = ../../i386/shared/irq/irq.h
> include_bsp_HEADERS += ../../i386/shared/irq/irq_asm.h
> include_bsp_HEADERS += ../../i386/shared/comm/tty_drv.h
> +include_bsp_HEADERS += ../../i386/shared/realmode_int/realmode_int.h
> include_bsp_HEADERS += ../../shared/include/irq-generic.h
> include_bsp_HEADERS += ../../shared/include/irq-info.h
> include_bsp_HEADERS += console/rtd316.h
> @@ -94,6 +95,7 @@ libbsp_a_SOURCES += console/kbd_parser.c
> libbsp_a_SOURCES += console/serial_mouse_config.c
> libbsp_a_SOURCES += ../../i386/shared/comm/uart.c
> libbsp_a_SOURCES += ../../i386/shared/comm/tty_drv.c
> +libbsp_a_SOURCES += ../../i386/shared/realmode_int/realmode_int.c
> libbsp_a_SOURCES += ../../shared/console.c
> libbsp_a_SOURCES += console/console_select.c
> libbsp_a_SOURCES += ../../shared/console_read.c
> diff --git a/c/src/lib/libbsp/i386/pc386/preinstall.am b/c/src/lib/libbsp/i386/pc386/preinstall.am
> index 825023a..4314f22 100644
> --- a/c/src/lib/libbsp/i386/pc386/preinstall.am
> +++ b/c/src/lib/libbsp/i386/pc386/preinstall.am
> @@ -65,6 +65,10 @@ $(PROJECT_INCLUDE)/bsp/tty_drv.h: ../../i386/shared/comm/tty_drv.h $(PROJECT_INC
> $(INSTALL_DATA) $< $(PROJECT_INCLUDE)/bsp/tty_drv.h
> PREINSTALL_FILES += $(PROJECT_INCLUDE)/bsp/tty_drv.h
>
> +$(PROJECT_INCLUDE)/bsp/realmode_int.h: ../../i386/shared/realmode_int/realmode_int.h $(PROJECT_INCLUDE)/bsp/$(dirstamp)
> + $(INSTALL_DATA) $< $(PROJECT_INCLUDE)/bsp/realmode_int.h
> +PREINSTALL_FILES += $(PROJECT_INCLUDE)/bsp/realmode_int.h
> +
> $(PROJECT_INCLUDE)/bsp/irq-generic.h: ../../shared/include/irq-generic.h $(PROJECT_INCLUDE)/bsp/$(dirstamp)
> $(INSTALL_DATA) $< $(PROJECT_INCLUDE)/bsp/irq-generic.h
> PREINSTALL_FILES += $(PROJECT_INCLUDE)/bsp/irq-generic.h
> diff --git a/c/src/lib/libbsp/i386/shared/realmode_int/realmode_int.c b/c/src/lib/libbsp/i386/shared/realmode_int/realmode_int.c
> new file mode 100644
> index 0000000..0aa71e6
> --- /dev/null
> +++ b/c/src/lib/libbsp/i386/shared/realmode_int/realmode_int.c
> @@ -0,0 +1,406 @@
> +/*
> + * Realmode interrupt call implementation.
> + *
Two issues:
+ Copyright and file description should be in separate comment
blocks. The file description comment block comes first and should
use Doxygen notation. The copyright block should be separate.
If you combine them, you end up with copyright information being
sucked into Doxygen output.
+ "Realmode" should be "Real mode"
Make sure those are OK in all files.
> + *
> + * Copyright (c) 2014 - CTU in Prague
> + * Jan Doležal ( dolezj21 at fel.cvut.cz )
> + *
> + * The license and distribution terms for this file may be
> + * found in the file LICENSE in this distribution or at
> + * http://www.rtems.org/license/LICENSE.
> + *
> + */
> +
> +#include <bsp/realmode_int.h>
> +#include <string.h>
> +#include <rtems/score/cpu.h>
> +
> +#define IR_EAX_OFF "0x00"
> +#define IR_EBX_OFF "0x04"
> +#define IR_ECX_OFF "0x08"
> +#define IR_EDX_OFF "0x0C"
> +#define IR_ESI_OFF "0x10"
> +#define IR_EDI_OFF "0x14"
> +#define IR_DS_OFF "0x18"
> +#define IR_ES_OFF "0x1A"
> +#define IR_FS_OFF "0x1C"
> +#define IR_GS_OFF "0x1E"
> +
> +#define BKP_ESP_OFF "0x20"
> +#define BKP_SS_OFF "0x24"
> +#define BKP_DS_OFF "0x26"
> +#define RM_ENTRY "0x28"
> +#define PM_ENTRY "0x2C"
> +
> +/* parameters, results, backup values accessible in real mode */
> +typedef struct {
> + i386_realmode_interrupt_registers inoutregs;
> + uint32_t pm_esp_bkp;
> + uint16_t pm_ss_bkp;
> + uint16_t ds_bkp;
> + uint16_t rm_entry;
> + uint16_t rm_code_segment;
> + uint32_t pm_entry;
> + uint16_t pm_code_selector;
> + /* if modifying update offset definitions as well */
> +} RTEMS_COMPILER_PACKED_ATTRIBUTE rm_int_regs_bkp_param;
> +
> +#define BKP_IDTR_LIM "0x00"
> +#define BKP_IDTR_BASE "0x02"
> +#define BKP_ES_OFF "0x06"
> +#define BKP_FS_OFF "0x08"
> +#define BKP_GS_OFF "0x0A"
> +#define RML_ENTRY "0x0C"
> +#define RML_D_SEL "0x12"
> +#define RM_SS "0x14"
> +#define RM_SP "0x16"
> +#define RM_DS "0x18"
Space needed to separate things.
We would **REALLY** like the structure and method comments
in all files to be in Doxygen format but after consultation with
Gedare, just do it in a follow up patch. Fix everything else and
then do another patch once merged to address Doxygen.
> +/* backup values, pointers/parameters accessible in protected mode */
> +typedef struct {
> + uint16_t idtr_lim_bkp;
> + uint32_t idtr_base_bkp;
> + uint16_t es_bkp;
> + uint16_t fs_bkp;
> + uint16_t gs_bkp;
> + uint32_t rml_entry;
> + uint16_t rml_code_selector;
> + uint16_t rml_data_selector;
> + uint16_t rm_stack_segment;
> + uint16_t rm_stack_pointer;
> + uint16_t rm_data_segment;
> +} RTEMS_COMPILER_PACKED_ATTRIBUTE pm_bkp_and_param;
> +
> +/* addresses where we are going to put Interrupt buffer,
> + * parameter/returned/preserved values, stack and copy code
> + * for calling BIOS interrupt real mode interface
> + * The value is chosen arbitrarily in the first 640kB
> + * to be accessible for real mode. It should be out of range
> + * used by RTEMS because its base address is above 1MB.
> + * It has to be above first 4kB (or better 64kB) which could
> + * be used by BIOS.
> + */
> +#define REAL_MODE_SPOT 0x12000
> +/* REAL_MODE_SPOT value is also top of real mode stack */
> +
> +/* buffers positions and lengths */
> +#define DEFAULT_BUFFER_SIZE 512
> +static void *default_rm_buffer_spot = (void *)REAL_MODE_SPOT;
> +static uint16_t default_rm_buffer_size = DEFAULT_BUFFER_SIZE;
> +
> +/* real mode stack */
> +#define STACK_SIZE 8192
> +#define INT_STACK_TOP REAL_MODE_SPOT
> +
> +/******************************
> + * STACK * *
> + ****************************** REAL_MODE_SPOT
> + * INT_BUF * 512 B *
> + ******************************
> + * INT_REGs * 50 B *
> + ******************************
> + * INT_FNC *~149 B *
> + ******************************/
> +
> +#define __DP_TYPE uint8_t
> +#define __DP_YES ((__DP_TYPE)1)
> +#define __DP_NO ((__DP_TYPE)-1)
> +#define __DP_FAIL ((__DP_TYPE)0)
> +static __DP_TYPE descsPrepared = __DP_NO;
> +
> +/* rml - real mode alike */
> +#define rml_limit 0xFFFF
> +static uint16_t rml_code_dsc_index = 0;
> +static uint16_t rml_data_dsc_index = 0;
> +
> +/*
> + * Prepares real-mode like descriptors to be used for switching
> + * to real mode.
> + *
> + * @retval __DP_YES descriptors are prepared
> + * @retval __DP_FAIL descriptors allocation failed (GDT too small)
> + */
> +static __DP_TYPE prepareRMDescriptors (void *base32) {
> + static void *prevBase = (void *)-1;
> + /* check if descriptors were prepared already */
> + if (descsPrepared == __DP_YES && prevBase == base32)
> + return descsPrepared;
> +
> + if (descsPrepared == __DP_FAIL)
> + return descsPrepared;
> +
> + /* create 'real mode like' segment descriptors, for switching to real mode */
> + rml_code_dsc_index = i386_next_empty_gdt_entry();
> + if (rml_code_dsc_index == 0)
> + {
> + /* not enough space in GDT */
> + descsPrepared = __DP_FAIL;
> + return descsPrepared;
> + }
> +
> + segment_descriptors flags_desc;
> + memset(&flags_desc, 0, sizeof(flags_desc));
> + flags_desc.type = 0xE; /* bits 4 */
> + flags_desc.descriptor_type = 0x1; /* bits 1 */
> + flags_desc.privilege = 0x0; /* bits 2 */
> + flags_desc.present = 0x1; /* bits 1 */
> + flags_desc.available = 0x0; /* bits 1 */
> + flags_desc.fixed_value_bits = 0x0; /* bits 1 */
> + flags_desc.operation_size = 0x0; /* bits 1 */
> + flags_desc.granularity = 0x0; /* bits 1 */
> + i386_fill_segment_desc_base((unsigned)base32, &flags_desc);
> + i386_fill_segment_desc_limit(rml_limit, &flags_desc);
> + if (i386_raw_gdt_entry(rml_code_dsc_index, &flags_desc) == 0)
> + {
> + /* selector to GDT out of range */
> + descsPrepared = __DP_FAIL;
> + return descsPrepared;
> + }
> +
> + rml_data_dsc_index = i386_next_empty_gdt_entry();
> + if (rml_data_dsc_index == 0)
> + {
> + /* not enough space in GDT for both descriptors */
> + descsPrepared = __DP_FAIL;
> + return descsPrepared;
> + }
> +
> + flags_desc.type = 0x2; /* bits 4 */
> + if (i386_raw_gdt_entry(rml_data_dsc_index, &flags_desc) == 0)
> + {
> + /* selector to GDT out of range */
> + descsPrepared = __DP_FAIL;
> + return descsPrepared;
> + }
> + prevBase = base32;
> + descsPrepared = __DP_YES;
> + return descsPrepared;
> +}
> +
> +void *i386_get_default_rm_buffer(uint16_t *size) {
> + *size = default_rm_buffer_size;
> + return default_rm_buffer_spot;
> +}
> +
> +int i386_real_interrupt_call(uint8_t interruptNumber,
> + i386_realmode_interrupt_registers *ir)
> +{
> + uint32_t pagingon;
> + rm_int_regs_bkp_param *int_passed_regs_spot;
> + /* place where the code switching to realmode and executing
> + interrupt is coppied */
> + void *rm_swtch_code_dst;
> + void *rm_stack_top;
> +
> + size_t cpLength;
> + void *cpBeg;
> +
> + /* values that can be passed from protected mode are stored in this struct
> + and they are passed later to the inline assembler executing interrupt */
Is this comment over 80 columns? Please check for over 80 columns.
rtems-testing/.../check_submission has code to do that.
> + volatile pm_bkp_and_param pm_bkp, *pm_bkp_addr;
> + unsigned short unused_offset;
> +
> + __asm__ volatile( "\t"
> + "movl %%cr0, %%eax\n\t"
> + "andl %1, %%eax\n"
> + : "=a"(pagingon)
> + : "i"(CR0_PAGING)
> + );
> + if (pagingon)
> + return 0;
> +
> + /* located under 1MB for real mode to be able to get/set values */
> + int_passed_regs_spot = (rm_int_regs_bkp_param *)
> + (default_rm_buffer_spot+default_rm_buffer_size);
> + /* position for real mode code reallocation to the first 1MB of RAM */
> + rm_swtch_code_dst = (void *)((uint32_t)int_passed_regs_spot +
> + sizeof(*int_passed_regs_spot));
> + rm_stack_top = (void *)INT_STACK_TOP;
> +
> + if (prepareRMDescriptors(int_passed_regs_spot) != __DP_YES)
> + return 0;
> +
> + pm_bkp_addr = &pm_bkp;
> + i386_Physical_to_real(
> + rm_stack_top - STACK_SIZE,
> + (unsigned short *)&pm_bkp.rm_stack_segment,
> + (unsigned short *)&pm_bkp.rm_stack_pointer
> + );
> + pm_bkp.rm_stack_pointer += STACK_SIZE;
> + pm_bkp.rml_code_selector = (rml_code_dsc_index<<3);
> + pm_bkp.rml_entry = ((uint32_t)rm_swtch_code_dst -
> + (uint32_t)int_passed_regs_spot);
> + pm_bkp.rml_data_selector = (rml_data_dsc_index<<3);
> + i386_Physical_to_real(
> + int_passed_regs_spot,
> + (unsigned short *)&pm_bkp.rm_data_segment,
> + &unused_offset
> + );
> +
> + int_passed_regs_spot->inoutregs = *ir;
> + /* offset from the beginning of coppied code */
> + uint16_t rm_entry_offset;
> + __asm__ volatile(
> + "movw $(rment-cp_beg), %0\n\t"
> + : "=r"(rm_entry_offset)
> + );
> + i386_Physical_to_real(
> + rm_swtch_code_dst+rm_entry_offset,
> + (unsigned short *)&int_passed_regs_spot->rm_code_segment,
> + (unsigned short *)&int_passed_regs_spot->rm_entry
> + );
> + __asm__ volatile(
> + "movl $(cp_end), %0\n\t"
> + "movw %%cs, %1\n\t"
> + : "=mr"(int_passed_regs_spot->pm_entry),
> + "=mr"(int_passed_regs_spot->pm_code_selector)
> + );
> + /* copy code for switch to real mode and
> + executing interrupt to first MB of RAM */
> + __asm__ volatile( "\t"
> + "mov $cp_end-cp_beg, %0\n\t"
> + "mov $cp_beg, %1\n\t"
> + : "=rm"(cpLength), "=rm"(cpBeg)
> + );
> + memcpy(rm_swtch_code_dst, cpBeg, cpLength);
> + /* write interrupt number to be executed */
> + uint16_t interrupt_number_off;
> + uint8_t *interrupt_number_ptr;
> + __asm__ volatile( "\t"
> + "movw $intnum-cp_beg, %0\n\t"
> + : "=rm"(interrupt_number_off)
> + );
> + interrupt_number_ptr = (uint8_t *)(rm_swtch_code_dst+interrupt_number_off);
> + *interrupt_number_ptr = interruptNumber;
> + /* execute code that jumps to coppied function, which switches to real mode,
> + loads registers with values passed to interrupt and executes interrupt */
> + __asm__ volatile( "\t"
> + /* backup stack */
> + "movl %[regs_spot], %%ebx\n\t"
> + "movl %%esp, "BKP_ESP_OFF"(%%ebx)\n\t"
> + "movw %%ss, "BKP_SS_OFF"(%%ebx)\n\t"
> + /* backup data selector */
> + "movw %%ds, "BKP_DS_OFF"(%%ebx)\n\t"
> + /* backup other selectors */
> + "movl %[pm_bkp], %%esi\n\t"
> + "movw %%es, "BKP_ES_OFF"(%%esi)\n\t"
> + "movw %%fs, "BKP_FS_OFF"(%%esi)\n\t"
> + "movw %%gs, "BKP_GS_OFF"(%%esi)\n\t"
> + /* hopefully loader does not damage interrupt table on the beginning of
> + memory; that means length: 0x3FF, base: 0x0 */
> + /* preserve idtr */
> + "movl %%esi, %%eax\n\t"
> + "addl $"BKP_IDTR_LIM", %%eax\n\t"
> + "cli\n\t"
> + "sidt (%%eax)\n\t"
> + "movl $rmidt, %%eax\n\t"
> + "lidt (%%eax)\n\t"
> + /* prepare 'real mode like' data selector */
> + "movw "RML_D_SEL"(%%esi), %%ax\n\t"
> + /* prepare real mode data segment value */
> + "xorl %%edx,%%edx\n\t"
> + "movw "RM_DS"(%%esi), %%dx\n\t"
> + /* prepare real mode stack values */
> + "movw "RM_SS"(%%esi), %%cx\n\t"
> + "movzwl "RM_SP"(%%esi), %%esp\n\t"
> + /* jump to copied function and */
> + /* load 'real mode like' code selector */
> + "ljmp *"RML_ENTRY"(%%esi)\n"
> +"rmidt:"/* limit and base for realmode interrupt descriptor table */
> + ".word 0x3FF\n\t"
> + ".long 0\n\t"
> + /* load 'real mode like' data selectors */
> +"cp_beg: .code16\n\t"
> + "movw %%ax, %%ss\n\t"
> + "movw %%ax, %%ds\n\t"
> + "movw %%ax, %%es\n\t"
> + "movw %%ax, %%fs\n\t"
> + "movw %%ax, %%gs\n\t"
> + /* disable protected mode */
> + "movl %%cr0, %%eax\n\t"
> + "and %[cr0_prot_dis], %%ax\n\t"
> + "movl %%eax, %%cr0\n\t"
> + /* base for data selector of 16-bit protected mode is
> + at beginning of passed regs */
> + /* flush prefetch queue by far jumping */
> + "ljmp *"RM_ENTRY"\n\t"
> +"rment: "
> + /* establish rm stack - esp was already set in 32-bit protected mode*/
> + "movw %%cx, %%ss\n\t"
> + /* set data segment (value prepared in 32-bit prot mode) */
> + "movw %%dx, %%ds\n\t"
> + /* count real mode pointer so we don't need to overuse address
> + prefix (by using 32bit addresses in 16bit context) */
> + "shll $4,%%edx\n\t"
> + "subl %%edx,%%ebx\n\t"
> + /* prepare values to be used after interrupt call */
> + "pushw %%bx\n\t"
> + "pushw %%ds\n\t"
> + /* fill registers with parameters */
> + "movw " IR_DS_OFF"(%%bx), %%ax\n\t"
> + "pushw %%ax\n\t"
> + "movl "IR_EAX_OFF"(%%bx), %%eax\n\t"
> + "movl "IR_ECX_OFF"(%%bx), %%ecx\n\t"
> + "movl "IR_EDX_OFF"(%%bx), %%edx\n\t"
> + "movl "IR_EDI_OFF"(%%bx), %%edi\n\t"
> + "movl "IR_ESI_OFF"(%%bx), %%esi\n\t"
> + "movw " IR_ES_OFF"(%%bx), %%es\n\t"
> + "movw " IR_FS_OFF"(%%bx), %%fs\n\t"
> + "movw " IR_GS_OFF"(%%bx), %%gs\n\t"
> + /* prepare ebx register */
> + "movl "IR_EBX_OFF"(%%bx), %%ebx\n\t"
> + /* prepare ds */
> + "popw %%ds\n\t"
> + /* interrupt instruction */
> + ".byte 0xCD\n\t"
> +"intnum: .byte 0x0\n\t"
> + /* fill return structure */
> + "pushw %%ds\n\t"
> + "pushl %%ebx\n\t"
> + "movw 0x6(%%esp), %%ds\n\t"
> + "movw 0x8(%%esp),%%bx\n\t" /* regs_spot */
> + "movl %%eax,"IR_EAX_OFF"(%%bx)\n\t"
> + "popl %%eax\n\t"
> + "movl %%eax,"IR_EBX_OFF"(%%bx)\n\t"
> + "movl %%ecx,"IR_ECX_OFF"(%%bx)\n\t"
> + "movl %%edx,"IR_EDX_OFF"(%%bx)\n\t"
> + "movl %%esi,"IR_ESI_OFF"(%%bx)\n\t"
> + "movl %%edi,"IR_EDI_OFF"(%%bx)\n\t"
> + "popw %%ax\n\t"
> + "movw %%ax, " IR_DS_OFF"(%%bx)\n\t"
> + "movw %%es, " IR_ES_OFF"(%%bx)\n\t"
> + "movw %%fs, " IR_FS_OFF"(%%bx)\n\t"
> + "movw %%gs, " IR_GS_OFF"(%%bx)\n\t"
> + /* prepare protected mode data segment */
> + "movw "BKP_DS_OFF"(%%bx), %%ax\n\t"
> + /* restore protected mode stack values */
> + "movl "BKP_ESP_OFF"(%%bx),%%esp\n\t"
> + "movw "BKP_SS_OFF"(%%bx), %%dx\n\t"
> + /* return to protected mode */
> + "movl %%cr0, %%ecx \n\t"
> + "or %[cr0_prot_ena], %%cx\n\t"
> + "movl %%ecx, %%cr0 \n\t"
> + "ljmpl *"PM_ENTRY"(%%bx)\n\t"
> + ".code32\n"
> + /* reload segmentation registers */
> +"cp_end:"
> + "movw %%ax, %%ds\n\t"
> + /* restore stack segment in protected mode context */
> + "movw %%dx, %%ss\n\t"
> + "movl %[pm_bkp], %%esi\n\t"
> + "movw "BKP_ES_OFF"(%%esi), %%es\n\t"
> + "movw "BKP_FS_OFF"(%%esi), %%fs\n\t"
> + "movw "BKP_GS_OFF"(%%esi), %%gs\n\t"
> + /* restore IDTR */
> + "addl $"BKP_IDTR_LIM", %%esi\n\t"
> + "lidt (%%esi)\n\t"
> + :
> + : [regs_spot]"m"(int_passed_regs_spot),
> + [pm_bkp]"m"(pm_bkp_addr),
> + [cr0_prot_ena]"i"(CR0_PROTECTION_ENABLE),
> + [cr0_prot_dis]"i"(~CR0_PROTECTION_ENABLE)
> + : "memory", "ebx", "ecx", "edx", "esi", "edi"
> + );
> + *ir = int_passed_regs_spot->inoutregs;
> + return 1;
> +}
> +
> diff --git a/c/src/lib/libbsp/i386/shared/realmode_int/realmode_int.h b/c/src/lib/libbsp/i386/shared/realmode_int/realmode_int.h
> new file mode 100644
> index 0000000..e5f80d0
> --- /dev/null
> +++ b/c/src/lib/libbsp/i386/shared/realmode_int/realmode_int.h
> @@ -0,0 +1,85 @@
> +/**
> + * @file realmode_int.h
> + *
> + * @ingroup i386_shared
> + *
> + * @brief Definitioins supporting real mode interrupt calls.
> + */
> +
> +/*
> + * Interface allows calling given interrupt number with content of the
> + * registers defined. For passing or receiving higher amounts of the data
> + * there is a buffer accessible from real mode available. Real mode pointer
> + * to this buffer is passed to the interrupt in the registers.
> + *
This comment should be in the top of the file.
> + * Copyright (C) 2014 Jan Doležal (dolezj21 at fel.cvut.cz)
> + * CTU in Prague.
> + *
> + * The license and distribution terms for this file may be
> + * found in the file LICENSE in this distribution or at
> + * http://www.rtems.org/license/LICENSE.
> + */
> +
> +#ifndef _REALMODE_INT_H
> +#define _REALMODE_INT_H
> +
> +#include <libcpu/cpu.h>
> +#include <stdint.h>
> +
> +#ifndef ASM /* ASM */
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif /* __cplusplus */
> +
> +/* --- BIOS service interrupt number --- */
> +/* number of interrupt servicing video functions */
> +#define INTERRUPT_NO_VIDEO_SERVICES 0x10
> +
> +typedef struct { /* used for passing parameters, fetching results and preserving values */
> + uint32_t reg_eax;
> + uint32_t reg_ebx;
> + uint32_t reg_ecx;
> + uint32_t reg_edx;
> + uint32_t reg_esi;
> + uint32_t reg_edi;
> + uint16_t reg_ds;
> + uint16_t reg_es;
> + uint16_t reg_fs;
> + uint16_t reg_gs;
> +} RTEMS_COMPILER_PACKED_ATTRIBUTE i386_realmode_interrupt_registers;
> +
> +/**
> + * Provides position to real mode buffer. It is buffer
> + * accessible from real mode context - it is located below
> + * address ~0x100000 in order for it to be accessible
> + * This buffer is meant to be pointed to by segReg:GenPurpReg
> + * and through this get bigger portion of an information to/from
> + * interrupt service routine than just by using register.
> + *
> + * @param size pointer to variable, where the size of buffer
> + * will be filled
> + * @retval pointer to buffer
> + */
> +extern void *i386_get_default_rm_buffer(uint16_t *size);
> +
> +/**
> + * This function allows calling interrupts in real mode and to set processor
> + * registers as desired before interrupt call is made and to retrieve the
> + * registers content after call was made.
> + *
> + * @param interruptNumber interrupt number to be called
> + * @param ir pointer to structure containing registers to be passed to interrupt
Again could be too long.
> + * and to retrieve register content after call was made.
> + * @retval 0 call failed (GDT too small or pagin is on)
> + * 1 call successful
> + */
> +extern int i386_real_interrupt_call(uint8_t interruptNumber, i386_realmode_interrupt_registers *ir);
> +
> +#ifdef __cplusplus
> +}
> +#endif /* __cplusplus */
> +
> +#endif /* ASM */
> +
> +#endif /* _REALMODE_INT_H */
> --
> 1.9.1
>
> _______________________________________________
> devel mailing list
> devel at rtems.org
> http://lists.rtems.org/mailman/listinfo/devel
--
Joel Sherrill, Ph.D. Director of Research & Development
joel.sherrill at OARcorp.com On-Line Applications Research
Ask me about RTEMS: a free RTOS Huntsville AL 35805
Support Available (256) 722-9985
More information about the devel
mailing list