<PAGE>   1
                                                                   EXHIBIT 10.12

                       ASSUMPTION AND FOURTH AMENDMENT TO
                 AMENDED AND RESTATED REVOLVING CREDIT AGREEMENT

     THIS ASSUMPTION AND FOURTH AMENDMENT (this "AMENDMENT") made this 10th day
of October, 2000, is by and among O'CHARLEY'S INC., a Tennessee corporation
("ORIGINAL BORROWER"), OCI, INC., a Delaware corporation ("OCI"), O'CHARLEY'S
SPORTS BAR, INC., an Alabama corporation ("SPORTS BAR"), AIR TRAVEL SERVICES,
INC., a Tennessee corporation ("AIR TRAVEL"), O'CHARLEY'S MANAGEMENT COMPANY,
INC., a Tennessee corporation ("MANAGEMENT COMPANY"), DFI, INC., a Tennessee
corporation ("DFI"), O'CHARLEY'S RESTAURANT PROPERTIES, LLC, a Delaware limited
liability company, ("RESTAURANT PROPERTIES"), O'CHARLEY'S SERVICE COMPANY, INC.,
a Tennessee corporation ("SERVICE COMPANY"); individually, OCI, Sports Bar, Air
Travel, Management Company, DFI, Restaurant Properties and Service Company are
sometimes referred to herein as an "ADDITIONAL BORROWER" and when referencing
two or more of such entities, they are sometimes referred to herein as
"ADDITIONAL BORROWERS"); STONEY RIVER LEGENDARY MANAGEMENT, L.P., a Georgia
limited partnership, and STONEY RIVER MANAGEMENT COMPANY, INC., a Delaware
corporation (each a "NEW BORROWER" and collectively, the "NEW BORROWERS"), the
Original Borrower, the Additional Borrowers and the New Borrowers are sometimes
referred to herein, individually and collectively, as a "BORROWER" and the
"BORROWERS"), each of the undersigned Banks, BANK OF AMERICA, N.A., a national
banking association, successor in interest by merger to NationsBank, N.A., as a
Bank and as Co-Agent, and AMSOUTH BANK, an Alabama state bank, successor in
interest by merger to First American National Bank ("AGENT") as a Bank and as
Agent for the Banks.

                                    RECITALS:

     Pursuant to that certain Amended and Restated Revolving Credit Agreement,
dated as of December 8, 1997 (the "AMENDED AND RESTATED AGREEMENT") by and among
the Banks (other than SunTrust Bank) and Bank One, N.A. ("BANK ONE") (herein,
the "ORIGINAL BANKS") and the Original Borrower, the Original Banks made certain
loans (the "LOANS") in two separate facilities, to the Original Borrower, in an
aggregate amount of up to $100,000,000.00. Pursuant to an Assumption Agreement
and Amendment to Amended and Restated Revolving Credit Agreement dated December
7, 1998, an Assumption Agreement and Second Amendment to Amended and Restated
Revolving Credit Agreement dated December 8, 1999 and a Third Amendment to
Amended and Restated Revolving Credit Agreement dated January 31, 2000, the
Amended and Restated Agreement was amended to restructure the Loans to, among
other things, include the Additional Borrowers as borrowers thereunder, to
increase the applicable principal amount of the Loans to $135,000,000.00,
combine the Loans into one credit facility, and to provide for the departure of
Bank One and the addition of SunTrust, as a Bank (the Amended and Restated
Agreement, as so amended, is hereinafter referred to as the "AGREEMENT").
Capitalized terms not otherwise defined herein shall have the same meaning as in
the Agreement. The Original Borrower and the Additional Borrowers have requested
that the Banks restructure such loans to add each New Borrower as a Borrower
under the credit facility governed by the Agreement and to decrease the
Commitment of the Banks dollar for dollar according to the pro-rata interests in
the Loans of the Lenders, as transactions under the Synthetic Lease Facility (as
such term is hereafter defined) are closed, up to an aggregate reduction in
principal of $25,000,000.

     NOW, THEREFORE, in consideration of the foregoing premises, and other good
and valuable consideration, the receipt and sufficiency of which is hereby
acknowledged, the parties hereto agree as follows:

     1. Each New Borrower hereby joins in and assumes each of the obligations,
covenants and conditions set forth in the Agreement, as hereby amended, and
agrees to be bound by all of the terms thereof and further assumes and agrees to
pay, jointly and severally with the Original





<PAGE>   2

Borrower and the Additional Borrowers, the indebtedness evidenced by the Notes
and other Obligations.

     2. The parties acknowledge that Firstar Bank, N.A. ("Firstar") is the
successor-in-interest to Mercantile Bank, National Association ("Mercantile"),
and agree that the Agreement is and all loan documents executed in connection
therewith are hereby amended to the extent necessary to substitute therein a
reference to Firstar for every reference therein to Mercantile. By signing this
Amendment, Firstar acknowledges that it has assumed the duties and obligations
of Mercantile under the Agreement and all documents related thereto.

     3. Section 1 of the Agreement entitled "DEFINITIONS" is hereby further
amended by amending the following definitions:

          "Borrowers" or "Borrower" means O'Charley's Inc., OCI, Inc.,
     O'Charley's Sports Bar, Inc., Air Travel Services, Inc., O'Charley's
     Management Company, Inc., DFI, Inc., O'Charley's Restaurant Properties,
     LLC, O'Charley's Service Company, Inc., Stoney River Legendary Management,
     L.P. and Stoney River Management Company, Inc., individually and/or
     collectively.

          "Lessor Investment" has the meaning accorded such term in the
     definition of "Maximum Revolver Amount".

          "Loan" means any funds which any Bank has advanced or will advance to
     the Borrowers on a revolving basis pursuant to its Commitment under the
     Loan Facility or the Swingline Facility, and shall include advances in the
     form of letters of credit issued in accordance with the terms of this
     Agreement, and "Loans" means all such advances by all Banks up to the
     aggregate amount of the Maximum Revolver Amount.

          "Loan Facility" means the revolving line of credit facility described
     in Section 2.1, in the aggregate principal amount of the Maximum Revolver
     Amount.

          "Majority Banks" means Banks holding at least sixty-six and two-thirds
     percent (66 2/3%) of the then aggregate unpaid principal amounts of the
     Notes held by the Banks, or if no such principal amounts are outstanding,
     Banks have at least sixty-six and two-thirds percent (66 2/3%) of the Total
     Commitments.

          "Maximum Revolver Amount" means $135,000,000 less the sum of (a) the
     aggregate outstanding principal balance from time to time under the A Notes
     and the B Notes issued by the Synthetic Lessor (as "A Notes" and "B Notes"
     are defined in the Participation Agreement), and (b) the total amount of
     the Lessor Investment invested by the Synthetic Lessor (as "Lessor
     Investment" is defined in the Participation Agreement) that is outstanding
     from time to time.

          "Participation Agreement" means that certain Participation Agreement
     executed by Original Borrower, Synthetic Lessor, Agent and the Banks, dated
     on or about even date herewith.

          "Synthetic Lease Facility" means the synthetic lease facility
     described in the Participation Agreement.

          "Synthetic Lessor" means First American Business Capital, Inc.

          "Total Commitments" means the aggregate of the several Commitments of
     the Banks in the principal amount of up to One Hundred Thirty-Five Million
     and 00/100 Dollars






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     ($135,000,000.00), as set forth in Section 2 of this Agreement, including
     the aggregate of the several Commitments as they may be reduced from time
     to time, as described in Section 2.1(A) of this Agreement.

     4. The second and third sentences of Section 2.1(A) of the Agreement are
hereby amended in their entirety to read as follows:

     Subject to the terms and conditions of and relying on the representations,
     warranties and covenants contained in this Agreement, for a period ending
     on the Loan Termination Date, each Bank agrees to fund severally, but not
     jointly, to the Borrowers up to the amount set forth below opposite their
     names, which for all of the Banks shall be the aggregate maximum principal
     amount of up to One Hundred Thirty-Five Million and 00/100 Dollars
     ($135,000,000.00). The maximum Commitment of each of the Banks and its
     respective percentage of the Total Commitments (the "COMMITMENT
     PERCENTAGE") of each Bank are as follows (it being understood and agreed
     that such maximum commitments will be automatically reduced, dollar for
     dollar in accordance with the Commitment Percentage of each Lender, as
     reductions occur in the Maximum Revolver Amount:

<TABLE>
<CAPTION>
         Bank                       Commitment Amount          Commitment Percentage
         ----                       -----------------          ---------------------
     <S>                            <C>                        <C>
     AmSouth Bank                      $32,500,000                  24.07407407%
     Bank of America, N.A.             $32,500,000                  24.07407407%
     Firstar Bank, N.A.                $20,000,000                  14.81481481%
     First Union National
       Bank                            $25,000,000                  18.51851852%
     SunTrust Bank                     $25,000,000                  18.51851852%
</TABLE>

     5. The second, third and fourth sentences of Section 2.1(D) of the
Agreement are hereby amended in their entirety to read as follows:

     The Swingline Facility shall be a sublimit of the Loan Facility. All Loans
     under the Swingline Facility will be Floating Rate Loans. Notwithstanding
     that the Swingline Facility shall be evidenced by a separate promissory
     note, the aggregate principal amount of all Loans that may be outstanding
     at any one time, plus the aggregate face amounts of all outstanding letters
     of credit issued in connection with the Loan Facility, may not exceed the
     Maximum Revolver Amount.

     6. Section 2.4 of the Agreement entitled "Facility Fee" is hereby amended
in its entirety to read as follows:

          2.4 Facility Fee.

          The Borrower shall pay to the Agent for the account of the Banks a
     Facility Fee per annum equal to (i) $135,000,000 beginning January 31, 2000
     until September 29, 2000 and the Maximum Revolver Amount, beginning
     September 29, 2000, until the Loan Termination Date, multiplied by (ii) the
     applicable fee percentage set forth in the Table attached to this Agreement
     as Schedule I-A. The Facility Fee shall be payable quarterly, in arrears,
     on the first business day following each fiscal quarter end, the first such
     payment being due on October 1, 2000. Any accrued and unpaid Facility Fee
     shall be paid on the Loan Termination Date.

     7. Subsection (R) of Section 4.1 of the Agreement is hereby amended in its
entirety to read as follows:


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<PAGE>   4


          (R) O'Charley's Inc. owns 100% of the issued and outstanding stock of
     OCI, Inc., O'Charley's Sports Bar, Inc., Air Travel Services, Inc.,
     O'Charley's Management Company, Inc., DFI, Inc., O'Charley's Service
     Company, Inc. and Stoney River Management Company, Inc., and DFI, Inc. owns
     100% of the outstanding membership interests of O'Charley's Restaurant
     Properties, LLC. O'Charley's Inc. owns 100% of the partnership interest in
     Stoney River Legendary Management, L.P. Except as set forth in the
     preceding sentence, none of the Borrowers owns an interest in any Person.

     8. Section 6.1 of the Agreement is hereby amended to add the following
subsection, at the end of Section 6.1, following existing subsection (M), to
read as follows:

          (N) Should any "Event of Default" occur under the Participation
     Agreement.

     9. The first sentence of Section 7.1 of the Agreement is hereby amended in
its entirety to read as follows:

     With respect to all funds advanced hereunder or under the Notes, AmSouth
     Bank, Bank of America, N.A., Firstar Bank, N.A., First Union National Bank,
     and SunTrust Bank shall be obligated to advance, in the aggregate under the
     Loan Facility at any particular time, the Maximum Revolver Amount in effect
     at such time, multiplied by the Commitment Percentage of such Bank.

     10. Section 8.5 of the Agreement is hereby amended in its entirety read as
follows:

     Section 8.5. Notices.

          Any notices or consents required or permitted by this Agreement shall
     be in writing and shall be deemed delivered in person, or when sent by
     certified mail, postage prepaid, return receipt requested or by overnight
     courier service, to the address as follows, unless such address is changed
     by written notice hereunder:

          (A)      If to the Borrower:

                   O'Charley's Inc.
                   P.O. Box 291809
                   Nashville, TN  37229
                   Attn: Chad Fitzhugh, Chief Financial Officer

                   cc:      J. Page Davidson, Esq.
                            Felix Dowsley, Esq.
                            Bass, Berry & Sims, PLC
                            AmSouth Center
                            315 Deaderick Street
                            Nashville, TN  37229

          (B)      If to the Agent:

                   AmSouth Bank
                   AmSouth Center
                   315 Deaderick Street
                   Nashville, TN  37237-0315
                   Attn: Mary Buckner, Sr. Vice President



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<PAGE>   5

                   cc:      Cynthia N. Sellers, Esq.
                            Farris, Warfield & Kanaday, PLC
                            424 Church Street, Suite 1800
                            Nashville, TN  37219

          (C)      If to Co-Agent:

                   Bank of America, N.A.
                   414 Union Street
                   Nashville, TN  37239
                   Attn: William Diehl, Sr. Vice President

          (D)      If to the Banks:

                   AmSouth Bank
                   AmSouth Center
                   315 Deaderick Street
                   Nashville, TN  37237-0202
                   Attn: Ken Dobbins, Sr. Vice President

                   Bank of America, N.A.
                   414 Union Street
                   Nashville, TN  37239
                   Attn: William Diehl, Sr. Vice President

                   Firstar Bank, N.A.
                   One Firstar Center, Tram 12-3
                   721 Locust Street
                   St. Louis, MO 63101
                   Attn: Eric J. Hartman, Assistant Vice President

                   First Union National Bank
                   301 South College Street, TW-10
                   Charlotte, NC 28288-0745
                   Attn: Mary J. Amatore, Vice President

                   SunTrust Bank
                   201 Fourth Avenue North
                   Nashville, TN  37219
                   Attn: Vipul Patel, Vice President

     11. The Exhibits to the Agreement described in Schedule X will be modified
as of the date of this Amendment by the corresponding Exhibits attached to this
Amendment.

     12. Conditions. The effectiveness of this Amendment is expressly contingent
upon Borrowers' delivery to Agent of the following amounts and documents, in
form and content acceptable to Agent, in its sole discretion:

          (a) This Amendment executed by the Borrowers;

          (b) Copies of the resolutions of each New Borrowers' governing boards,
     certified by the secretaries of each New Borrower as of the date of this
     Amendment, authorizing the




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     execution, delivery and performance of this Amendment, the other Loan
     Documents, and each other document to be delivered pursuant hereto;

          (c) Copies of each New Borrowers' charter or articles of organization,
     as applicable, all certified as of the most recent date practicable by the
     Secretary of State of its incorporation or formation, together with
     certificates dated the date of this Amendment of each New Borrowers'
     secretary to the effect that such charters or articles of organization have
     not been amended since the date of the aforesaid Secretary of State
     certifications;

          (d) Copies of each New Borrowers' by-laws or operating agreement, as
     applicable, all certified by each New Borrowers' secretary as of the date
     of this Amendment;

          (e) Certificates dated as of the date of this Amendment of each New
     Borrowers' secretary as to the incumbency and signatures of the officers of
     the New Borrowers executing this Amendment, the other Loan Documents, and
     each other document to be delivered pursuant hereto;

          (f) Certificates, as of the most recent dates practicable, of the
     aforesaid Secretary of State, the Secretary of State of each state in which
     each Borrower is qualified as foreign corporations or entities and of the
     department of revenue or taxation of the foreign states as to the good
     standing of each Borrower;

          (g) Written opinions of Bass, Berry & Sims, PLC, each Borrowers'
     counsel, dated the date of this Amendment and addressed individually to
     Agents and Banks, in form reasonably satisfactory to the Agents and Banks.

          (h) Payment of all reasonable costs and expenses incurred by Agent in
     connection with the Amendment, including, without limitation, reasonable
     attorneys' fees.

          (j) Payment to Agent of an amendment fee in the amount of $72,750, to
     be paid pro-rata to the Banks.

     13. Ratification. Subject to the terms hereof, each Borrower hereby
restates and ratifies, as of the date hereof, all the representations,
warranties and covenants contained in the Agreement in favor of Agent and Banks,
and confirms that the terms and conditions of the Agreement, as amended hereby,
remain in full force and effect, that no Event of Default under the Agreement
has occurred and continues to exist and that the terms of Article 8 of the
Agreement, as hereby amended, shall continue to govern the Agreement and shall
govern this Amendment.




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<PAGE>   7

     IN WITNESS WHEREOF, the parties hereby have duly executed this Agreement as
of the day and year first above written.

AGENT:                                   BORROWER:

AMSOUTH BANK                             O'CHARLEY'S INC.


By: /s/ Kenneth L. Dobbins               By: /s/ A. Chad Fitzhugh
   ----------------------------------        -----------------------------------

Title: Senior Vice President             Title: Treasurer
      -------------------------------           --------------------------------

CO-AGENT:                                OCI, INC.

BANK OF AMERICA, N.A.
                                         By: /s/ A. Chad Fitzhugh
                                             -----------------------------------

By:      /s/ William H. Diehl            Title: Treasurer
   ----------------------------------           --------------------------------

Title:   Senior Vice President
      -------------------------------

                                         O'CHARLEY'S SPORTS BAR, INC.
BANKS:

AMSOUTH BANK                             By: /s/ A. Chad Fitzhugh
                                             -----------------------------------


                                         Title: President
                                                --------------------------------
By: /s/ Kenneth L. Dobbins
   ----------------------------------
                                         AIR TRAVEL SERVICES, INC.
Title: Senior Vice President
      -------------------------------
                                         By: /s/ A. Chad Fitzhugh
                                             -----------------------------------

BANK OF AMERICA, N.A.                    Title: Treasurer
                                                --------------------------------

                                         O'CHARLEY'S MANAGEMENT
By:      /s/ William H. Diehl            COMPANY, INC.
   ----------------------------------

Title:   Senior Vice President           By: /s/ A. Chad Fitzhugh
      -------------------------------        -----------------------------------

                                         Title: Treasurer
                                                --------------------------------

FIRSTAR BANK, N.A.                       DFI, INC.


By:      /s/ Eric J. Hartman             By: /s/ A. Chad Fitzhugh
   ----------------------------------        -----------------------------------

Title:   Assistant Vice President        Title: Treasurer
      -------------------------------           --------------------------------


                    [Signatures Continued on Following Page]


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FIRST UNION NATIONAL BANK                O'CHARLEY'S RESTAURANT
                                         PROPERTIES, LLC

By:      /s/ Mary J. Amatore             By: /s/ A. Chad Fitzhugh
   ----------------------------------        -----------------------------------

Title:   Vice President                  Title: Secretary
      -------------------------------          ---------------------------------

SUNTRUST BANK                            O'CHARLEY'S SERVICE COMPANY, INC.

By:      /s/ Vipul Patel                 By: /s/ A. Chad Fitzhugh
   ----------------------------------        -----------------------------------

Title:   Vice President                  Title: Treasurer
      -------------------------------           --------------------------------






                                         STONEY RIVER LEGENDARY
                                         MANAGEMENT, L.P.

                                         By:    Stoney River Management
                                                Company, Inc., general partner

                                         By: /s/ A. Chad Fitzhugh
                                            ------------------------------------

                                         Title: Treasurer
                                               ---------------------------------


                                         STONEY RIVER MANAGEMENT
                                         COMPANY, INC.


                                         By: /s/ A. Chad Fitzhugh
                                            ------------------------------------

                                         Title: Treasurer
                                               ---------------------------------




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                                   SCHEDULE X



<TABLE>
<CAPTION>
Exhibits to Agreement to be modified           Modified Exhibits attached to Amendment
------------------------------------           ---------------------------------------
<S>                                            <C>
          Exhibit A-1                                    Exhibit A-2
          Exhibit B-1                                    Exhibit B-2
          Exhibit E-1                                    Exhibit E-2
          Exhibit F-1                                    Exhibit F-2
          Exhibit I-1                                    Exhibit I-2
          Exhibit J-1                                    Exhibit J-2
          Exhibit L-1                                    Exhibit L-2
          Exhibit M-1                                    Exhibit M-2
</TABLE>




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