diff options
| -rw-r--r-- | cpukit/score/cpu/i386/cpu_asm.S | 43 | ||||
| -rw-r--r-- | cpukit/score/cpu/i386/rtems/score/i386.h | 32 |
2 files changed, 75 insertions, 0 deletions
diff --git a/cpukit/score/cpu/i386/cpu_asm.S b/cpukit/score/cpu/i386/cpu_asm.S index 9b395678b8..f3ef4e2c38 100644 --- a/cpukit/score/cpu/i386/cpu_asm.S +++ b/cpukit/score/cpu/i386/cpu_asm.S @@ -327,6 +327,49 @@ SYM (i386_Physical_to_logical): movl ecx,eax /* eax = ecx */ ret +/* + * int i386_Physical_to_real( + * void *address, + * uint16_t *segment, + * uint16_t *offset + * ); + * + * Fills segment:offest realmode pointer counted from thirty-two bit physical + * address. + * Returns 0 if unconvertible, 1 if successfuly converted. + */ + +.set PHYS_PTR_ARG, 4 +.set RM_PTR_SEG_ARG, 8 +.set RM_PTR_OFF_ARG, 12 + + PUBLIC (i386_Physical_to_real) + +SYM (i386_Physical_to_real): + movl PHYS_PTR_ARG(esp),eax + cmpl $0x10FFF0, eax + js 1f + movl $0, eax + ret +1: cmpl $0x100000, eax + js 2f + subl $0xFFFF0, eax + movl RM_PTR_OFF_ARG(esp), ecx + movw ax, (ecx) + movl RM_PTR_SEG_ARG(esp), ecx + movw $0xFFFF, (ecx) + movl $1, eax + ret +2: movl eax, edx + and $0xF, ax + movl RM_PTR_OFF_ARG(esp), ecx + movw ax, (ecx) + shrl $4, edx + movl RM_PTR_SEG_ARG(esp), ecx + movw dx, (ecx) + movl $1, eax + ret + END_CODE END diff --git a/cpukit/score/cpu/i386/rtems/score/i386.h b/cpukit/score/cpu/i386/rtems/score/i386.h index 57569fc398..926627dccb 100644 --- a/cpukit/score/cpu/i386/rtems/score/i386.h +++ b/cpukit/score/cpu/i386/rtems/score/i386.h @@ -186,6 +186,38 @@ void *i386_Physical_to_logical( ); /* + * i386_Real_to_physical + * + * Converts real mode pointer {segment, offset} to physical address. + */ +RTEMS_INLINE_ROUTINE void *i386_Real_to_physical( + uint16_t segment, + uint16_t offset) +{ + return (void *)(((uint32_t)segment<<4)+offset); +} + +/* + * i386_Physical_to_real + * Retreives real mode pointer elements {segmnet, offset} from physical address + * Function returns the highest segment (base) address possible. + * Example: input address - 0x4B3A2 + * output segment - 0x4B3A + * offset - 0x2 + * input address - 0x10F12E + * output segment - 0xFFFF + * offset - 0xF13E + * + * return 0 address not convertible, must be less than 0x10FFEF + * 1 segment and offset extracted + */ +int i386_Physical_to_real( + void *address, + uint16_t *segment, + uint16_t *offset +); + +/* * "Simpler" names for a lot of the things defined in this file */ |